Monday, December 14, 2009

GEMINIDS 2009

This weekend, Earth passed through a stream of debris from 3200 Phaethon. In 1983 Whipple identified Phaethon like the parent of Geminid meteor stream. But it has never displayed unambiguous cometary activity.

The Geminids provide the most impressive meteor display of any of the annual showers.

Bill Cooke of NASA's Meteoroid Environment Office, prepared a plot showing how the shower has intensified since its discovery. Jupiter's gravity has been acting on Phaethon's debris stream, causing it to shift more and more toward Earth's orbit:


Preliminary counts from the International Meteor Organization (IMO) shows that the Geminids meteors reached a ZHR(max) ~ 130/150 around 20/21 UT of Dec. 13, so roughly 8/9 hours before the predicted peak scheduled for around 5 UT of Dec. 14.

Radio meteor observations all over the world seems to confirm that the peak arrived 4/5 hours early on the predictions:


(Credit: RMO)



According to IMO Meteor Shower Calendar "the Geminid peak has shown slight signs of variability in its rates and timing in recent years"

Our meteorcam, located in Castellammare di Stabia (Italy), imaged 44 meteors (35 were Geminids) on 12/13 December, one day before the peak. Unfortunately clouds prevented us to follow the Geminids through the maximum rate.

These are a composite image (because the images were collected over several hours, the radiant of the shower is spread out) + animation:




geminids video

The all-sky camera of Cloudbait Observatory (Colorado, Usa) recorded 419 Gemind meteors between sunset on December 9 and sunrise on December 14 (232 on on the peak night of December 13/14):

http://www.cloudbait.com/science/geminid2009.html#


by Ernesto Guido

References:

http://science.nasa.gov/headlines/y2009/08dec_geminids.htm

Wednesday, December 2, 2009

South African Fireball - November 21

After the Utah Fireball on Nov. 18, another bright fireball has been seen over South Africa aroud 11pm local time of Nov. 21, 2009. The meteor was spotted by dozens people as it passed over Johannesburg and Pretoria in Kauteng province on Saturday.

Footage from a security camera in Burgersfort in the Limpopo Province:


video

(Credit: Christo van Graan - Burgersfort)

This video has been captured from a security camera of the Mustek building in Midrand:



While here you can see a CCTV footage of the fireball over the skies of Gauteng:

Friday, November 27, 2009

NOVA ERIDANI 2009 - Update

According to the Cbets 2053 & 2055 the transient in Eridanus has been spectroscopically confirmed as a nova.

Spectra obtained on Nov. 26 by H. Maehara (Kyoto University) and by M. Fujii (Okayama) shows that the object seems likely to be an He/N-class nova

Moreover another spectrum obtained by NASA researchers using the Aerospace Near-Infrared Imaging Spectrograph on the 3-m Shane reflector of Lick Observatory shows very strong, broad emission lines and confirm this object as a nova.

In the meantime prediscovery measurements of Nova Eridani 2009 have been reported on VSNET mailing list by "Pi of the Sky” team.

According to their measurement the nova reached the magnitude 5.60 (R-filter) on Nov. 15:

20091113.301 7.10 R "Pi of the Sky"
20091114.304 5.71 R "Pi of the Sky"
20091115.308 5.60 R "Pi of the Sky"
20091116.302 5.92 R "Pi of the Sky"
20091117.297 6.09 R "Pi of the Sky"

Their light curve and a nice animation showing the first days after the outburst:

http://grb.fuw.edu.pl/pi/var/catac/nova_eri.htm


ASAS-3 system (Pojmanski 2002, Acta. Astron. 52, 397) also detected this object at the following V magnitudes:

Nov. 10.236 UT, [14.0:
Nov. 19.241, 7.34;
Nov. 22.179, 7.98;
Nov. 24.269, 8.12.

by Ernesto Guido

Thursday, November 26, 2009

POSSIBLE NOVA IN ERIDANUS

Following the posting on the Central Bureau's unconfirmed-objects webpage & Cbet No. 2050 about the discovery by K. Itagaki (Yamagata, Japan) of a possible Nova in Eri we performed some follow-up of this object remotely through a 0.25-m, f/3,4 reflector +CCD, from GRAS Observatory (near Mayhill, NM).

On our images taken on November 26.36 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 8.2 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 04 47 54.12, Decl.= -10 10 43.1
(equinox 2000.0; UCAC2 catalogue reference stars).

Our image:
http://bit.ly/5oZj01

A comparison with a DSS red plate (limiting magnitude about 20), obtained on 1990, Nov. 23, shows the proximity of a 15th-mag star to the position of the possible nova in Eri.

This is an animation showing our image and the DSS plate:

http://bit.ly/8N32kV

On the Cbet Yamaoka (Kyushu University) suggests that it might be the brightening of the 15th-mag blue star noting "that the amplitude of seven magnitudes is rather large for a dwarf nova, but somewhat small for a rapid classical nova".

Spectroscopic and time-resolved photometric observations are required to understand the real nature of this transient.

UPDATE

For an update about this object please see our Nov. 27, 2009 post:

http://remanzacco.blogspot.com/2009/11/nova-eridani-2009-update.html

by Ernesto Guido and Giovanni Sostero

Friday, November 20, 2009

Utah Fireball - 18 November 2009

On Nov. 18, just after midnight local time (MST) a great fireball was seen over parts of the western United States

According to Spaceweather website witness in Utah, Wyoming and Idaho saw "remarkable midnight fireball that turned night into day. It was not a Leonid. Infrasound measurements suggest a sporadic asteroid not associated with the Leonid debris stream. The space rock exploded in the atmosphere with an energy equivalent to 0.5 - 1 kilotons of TNT"

Many surveillance cameras have recorded the midnight-landscape illuminated by the fireball:

utah fireball,fireball

(click to enlarge)


Here you can find other videos of the fireball uploaded on youtube:

http://bit.ly/5pqVuW

http://bit.ly/4ZMSAY

http://bit.ly/7p2vpw

http://bit.ly/55ZRDa

http://bit.ly/80dBnS


Few hours after the fireball, strange clouds appeared in the dawn sky. These clouds are strikingly similar to the debris left in the sky after the 2008 TC3 event in Sudan on Oct. 7, 2008.


by Ernesto Guido

References:

http://www.spaceweather.com/

http://www.ksl.com/?nid=148&sid=8714738

Wednesday, November 18, 2009

Leonids 2009

According to preliminary counts from the International Meteor Organization (IMO) the Leonids meteors reached a ZHR(max) ~ 120/130 around 22UT of Nov. 17, as predicted by forecasters.



The ZHR surge, witnessed by observers in Asia, occurred when Earth passed through the debris left from Comet 55P/Tempel-Tuttle in 1466 AD and 1533 AD. When Earth exit these streams, the ZHR count fall to the value ~30/40.

Our meteorcam starting to image at 23:30 UT of Nov. 17. In 5 hours of imaging, our camera detected 35 meteors, of which 26 were leonids.

This is a composite of the brightest meteors (mostly leonids) imaged by the meteorcam from 23:30 UT of Nov.17 to 04:30 UT of Nov. 18 (because the images were collected over several hours, the radiant of the shower is spread out):


While checking online all-sky cameras around the web, I found this nice fireball imaged by the Sbig All-Sky camera on Nov. 17 at 02:20am local time:



Here you can see the video sequence showing the fireball and its trail:

Monday, November 9, 2009

NOVA SCUTI 2009

Following the posting on the Central Bureau's unconfirmed-objects webpage about a possible nova in Scuti, on 2009 November 09.08 we performed some follow-up of this object through a 0.25-m, f/3,4 reflector + CCD, from GRAS Observatory (near Mayhill, NM).

We can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 8.5 (UCAC-2 Catalogue reference stars) at coordinates:

R.A. = 18 43 45.57, Decl.= -07 36 42.0

(equinox 2000.0; UCAC-2 catalogue reference stars).

Our confirmation image:


A bigger version is available here:

The extreme stellar crowding due to nearby field stars makes this measurement rather difficult. A comparison with a DSS red plate(limiting magnitude about 20), obtained on 1996, Aug. 13, fail to show a clear unambiguous pre-outburst precursor.

This is an animation showing of our image and the DSS plate:

More details about the discoverer have been provided on the Cbet circular No. 2008, issued of 2009 November 09. The cbet announces the discovery of Hideo Nishimura(Japan) of a possible nova (mag 8) on two 10-s CCD frames (limiting magnitude 11.5) taken on Nov. 8.3699 and 8.3700 UT using a Canon EOS 5D camera (+ Minolta 120-mm f/3.5 lens).


by Ernesto Guido and Giovanni Sostero

Tuesday, October 27, 2009

NOVA SAGITTARII 2009 No. 4

Cbet circular No. 1994, issued on 2009 Oct. 26, announces the discovery by K. Nishiyama and F. Kabashima of an apparent new Nova (mag 9.3) on images taken with a 105-mm f/4 camera lens in the course of their nova survey. Nothing is visible on their two recent survey frames taken on 20 & 21 October 2009 (limiting magnitude 13.9).

On our images taken on October 27.09 through a 0.25-m, f/3.4 reflector + CCD, near Mayhill (NM), we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 9.0 (USNO-B1 Catalogue reference stars) at coordinates:


R.A. = 18 31 32.81, Decl.= -16 19 07.5
(equinox 2000.0; USNO-B1 catalogue reference stars).


Our image of this transient:



A bigger version (2.5 MB) of our image is available here:

http://bit.ly/mcYVl

by Ernesto Guido and Giovanni Sostero

Monday, October 26, 2009

Alan Young Award 2009

We have just received news that our team members Ernesto Guido & Giovanni Sostero have been awarded the 2009 "Alan Young" Award by the readers of "The Astronomer" magazine. TA is a magazine for the advanced amateur with the "aim to publish all observations of astronomical interest as soon as possible after they are made". The magazine has been published monthly since 1964 and subscribers are found all over the world.

The award is in memory of the late Alan Young.

Congratulations to Ernesto & Giovanni!!!

The Team

Thursday, October 15, 2009

Netherlands Fireball - October 13, 2009

A bright fireball has been reported to streak across the sky in the Netherlands by many observers at approximately 1658 UT on Oct. 13th. The bolide breaks apart into a half-dozen fragments, and a trail in the sky remained visible for many minutes.




(Credit: Jan de Vries)



(Credit: Robert Mikaelyan, The Netherlands)





(Credit: Maciej Libert, The Netherlands)


According to Spaceweather website: "Royal Dutch Meteorology Institute listening post detected strong infrasound (low-frequency sound) waves, apparently confirming a high-altitude breakup event":


More images of both the fireball and the trail can be seen here:




Several thousand meteors of fireball magnitude occur in the Earth's atmosphere each day. Most occur over the oceans and uninhabited regions and many are masked by daylight. The brighter the fireball, the more rare is the event.

by Ernesto Guido

Wednesday, September 30, 2009

New Comet Discovery: P/2009 QG31

IAU circular No. 9078, issued on 2009, Sept. 29, announces that an asteroidal object, discovered with a 0.45-m f/2.8 reflector + CCD by the "La Sagra Sky Survey" (Spain), has been reported to show cometary features by several observers, involved in its astrometric follow-up.

Our attention to this object with a peculiar orbit, has been drawn by one member of the "La Sagra" staff (R. Stoss, 2009 Sept. 10, private communication). Then we planned an observing campaign, asking some help to other fellow observers of the CARA collaboration (namely, P. Bacci, E. Bryssinck and R. Ligustri).

Our first attempt to investigate about the nature of this object, simply failed: the images obtained on 2009, Sept. 14, remotely from the Mayhill Station (NM) of the GRAS network, were of bad quality due to the presence of thin cyrrus clouds. Then, for several nights, bad weather conditions prevented us to perform further follow-up on it.

Finally, on Sept. 18.5, we succeed imaging it remotely with the 0.35-m f/7 reflector + CCD of the "Skylive" network (near Trunkey, Australia). At that time, the object was nearly 70 deg above the horizon, and the very good seeing allowed us to identify its tiny round coma, about 7-arcsec in diameter, having a total (unfiltered R) magnitude of about 19:


Further confirming observations were performed by other fellow observers we alerted, like the CARA memebers E. Bryssinck (remotely through the Tzec Maun 0.4-m reflector, NM, Sept. 16.3) and R. Ligustri (Talmassons, Italy, 0.35-m reflector; Sept. 19.9), who reported a coma ranging from 10 to 15-arcsec in diameter.

Other indipendent positive detections of cometary features on this object were performed by observers operating professional telescopes, like A. F. Tubbiolo and R. S. McMillan (Spacewatch 1.8-m reflector, Sept. 12.3), F. Hormuth (Calar Alto 3.5-m telescope, Sept. 17.9) and G. Muler (2-m Faulkes Telescope North, Sept. 18.4), that described a 10-15-arcsec diffuse coma.

According to the Minor Planet Center's database, this low-activity, Jupiter-family comet, completes a revolution around the Sun every 6.8 years, with a perihelion at about 2.1 Au from our star (that will be reached in Oct. 2009), and an aphelion at 5.0 AU; inclination above the ecliptic plane is about 5 deg. It's future visibility will be complicated by its declining brightness.

Congratulations to the "La Sagra Sky Survey" staff for their discovery.

by G. Sostero, E. Guido, P. Camilleri, M. Jaeger, W. Vollmann, and E. Prosperi

Monday, September 28, 2009

New Comet Discovery: P/2009 S2 (McNAUGHT)

IAUC nr. 9075, issued on 2009 Sept. 24th, announces the discovery of another comet by Robert McNaught, named P/2009 S2. This object has been picked-up by McNaught on 2009, Sept.20.7 in the southern constellation of Fornax, at about magnitude 19.

We performed some follow-up of this target remotely on 2009, Sept. 24.36 with a 0.25-m, f/3.4 reflector + CCD (near Mayhill, NM). Stacking of 15 unfiltered exposures, 120-seconds each, showed a coma nearly 10" in diameter, remarkably elongated in the same direction of a narrow tail, that was measured to be about 14" long in p.a. 255 deg.

Our image is available here:


Preliminaty orbital elements and ephemerids of this periodic comet has been published on M.P.E.C. 2009-S90:


Perihelion has been reached on June, 2009, at about 2.2 AU from the Sun. The orbit has an inclination of 28 degrees, and is completed in nearly 8.5 years. P/2009 S2 will mostly remain a faint southern comet for the rest of the current perihelium passage.

by Ernesto Guido and Giovanni Sostero

Thursday, September 24, 2009

New discovered PHA: 2009 ST19

This minor planet, belonging to the "Apollo" class, is also flagged as a "Potentially Hazardous Asteroid", an object that, because of its orbital parameters, might represent a possible threat of impact for planet Earth (http://neo.jpl.nasa.gov/neo/pha.html).

It has beeen discovered serendipitously by the Spanish amateur astronomer J. M. Bosch (Santa Maria de Montmagastrell, MPC#B74) on 2009, Sept. 16.2, ay magnitude about 17. At that time it was posted on the NEO-CP webpage of the Minor Planet Center as "jmbo11"; after a couple of days it was withdrawn, because it was not confirmed by any further observations.

On 2009, Sept. 22, the LINEAR sky survey picked-up a fast moving object, that was posted in the NEO-Cp as "BQ24981". After some follow-up observations from various sites, on 2009 Sept. 23 the MPC published M.P.E.C. 2009-S72 (http://tinyurl.com/yer5xmr), informing that the two objects mentioned before were actually the same celestial body.

We performed some follow-up of this object on 2009, Sept.23.1, remotely from the Mayhill Station (NM) of the GRAS network. You can see our image here:

http://tinyurl.com/yclpzns

According to the NEODyS webpage this object. about 0.5-Km in diameter, made a close pass to Earth on 1980, Oct. 4, at a minimum possible distance of about 0.009 AU (nominal distance of about 0.04 AU).

Congratulations to J. M. Bosch for his find.

E. Guido, G. Sostero, P. Camilleri, M. Jaeger, E. Prosperi, W. Vollmann

Wednesday, September 23, 2009

New Comet Discovery: P/2009 S1 (Gibbs)

IAU Circular nr. 9074 issued on 2009, Sep. 22, announces the discovery of a new comet by A. R. Gibbs, named P/2009 S1 (Gibbs).

It was found on Sep. 20 in the course of the Catalina Sky Survey with the Catalina 0.68-m Schmidt telescope.

After posting on the Minor Planet Center's 'NEOCP' webpage, other observers have noted the cometary appearance of this 18.5 - 19 magnitude object.

We have been able to confirm this object remotely, through the GRAS network, using a scope located in Mayhill (NM): on 2009, September 21.4, co-adding of 14 unfiltered exposures, 120 seconds each, obtained by means of a 0.25-m, f/3.4 reflector + CCD, show a condensed coma nearly 8" in diameter and a broad tail about 20" long in p.a. 260 deg.

Our image is available here:


The preliminary orbit for comet P/2009 S1 (Gibbs) indicates perihelion already on Jul. 25, 2009, at about 2.4 AU:


This is the 13th comet discovery for Gibbs.


by Ernesto Guido & Giovanni Sostero

Tuesday, September 15, 2009

Comet P/2009 R2 (PIGOTT-LINEAR-KOWALSKI)

IAUC no. 9072, issued on 2009, Sept. 11, announces the recovery of P/2003 A1 (LINEAR). This comet has been initially picked-up as a diffuse object (coma about 15-20 arcsec elongated in PA 280 deg) by R. A. Kowalski with the Catalina 0.68-m Schmidt telescope on 2009, Sept. 10.4.

Follow-up after its posting in the NEO-CP webpage was secured by several observers (P. Birtwhistle, G. Hug and the undersigneds), who noticed the presence of cometary features (in general, the existence of a small coma, about 10 arcsec in diameter with little or no central condensation, was reported).

D. Chestnov linked the new designated P/2009 R2 to P/2003 A1 (LINEAR). Probably due to a strong perturbation by Jupiter at the time of its aphelion (Sept. 2006), P/2009 R2 was found significantly off track (nearly 17 deg northeast of P/2003 A1 original ephemerids position).

IAUC No. 9073, published shortly after, informed us that B. G. Marsden successfully linked 14 astrometric data points collected in 1783 on comet Pigott (1783 W1) with the positions available so far on P/2009 R2 & P/2003 A1, establishing then that comet Pigott (1783 W1) had the same identity of P/2009 R2 & P/2003 A1.

Thus this object has been named as P/2009 R2 (PIGOTT-LINEAR-KOWALSKI).

M.P.E.C. 2009-R40, published on 2009, Sept. 11, details orbital solutions and preliminary ephemerids:


At first we imaged this object remotely, on Sept. 11.4, through the RAS network (MPC# H06, Mayhill, NM) with a 0.25-m, f/3.4 reflector + CCD: co-adding of 10 unfiltered exposures, 120-seconds each showed that this object was diffuse, without a clear central condensation (this created us some troubles establishing a useful photocenter for astrometrical purposes). Glare from a nearby field star prevented us to firmly establish a precise coma diameter, however in our images we saw at least 10 arcsec of coma.

Then we performed some additional follow-up on on 2009, Sept. 13.1, from the Malina River Observatory (MPC# B90, Povoletto, Italy) with a 0.25-m, f/11 reflector + CCD: stacking of 15 x 120-sec unfiltered exposures, confirmed the presence of a tiny coma, about 12-arcsec in diameter, with an extremely weak central condensation (40% illuminated Moon about 26-deg away).

Our image is available here:


by Ernesto Guido & Giovanni Sostero

Thursday, September 10, 2009

New Comet Discovery: C/2009 R1 (McNAUGHT)

IAU Circular nr.9071, issued on 2009, Sep. 10, announces the discovery of a new comet by R. H. McNaught, named C/2009 R1 (McNAUGHT). It was found on Sep. 09 in the course of the Siding Spring Survey with the 0.5-m Uppsala Schmidt telescope. Pre-discovery Uppsala Schmidt images taken by G. J. Garradd and McNaught on July 20, Aug. 1, and 18 have been identified by T. Spahr and B. G. Marsden in astrometry submitted to the Minor Planet Center.

After posting on the Minor Planet Center's 'NEOCP' webpage, other observers have noted the cometary appearance of this 17.5 magnitude object.

We have been able to confirm this object remotely, through the GRAS network, using a scope located in Mayhill (NM): on 2009, September 10.2, co-adding of 20 unfiltered exposures, 120 seconds each, obtained by means of a 0.25-m, f/3.4 reflector + CCD, show a coma of diameter about 12" with a hint of elongation toward p.a. 65 deg.

Our image is available here:



The preliminary orbit for comet C/2009 R1 (McNAUGHT) indicates perihelion on Jul. 02, 2010, at about 0.4 AU:


This comet may reach magnitude 5 at the end of June 2010, but the elongation will be very small (only 18 degree on June 27, 2010) and so the observing conditions.

This is the comet discovery number 51 for Robert McNaught.


UPDATE MAY 30, 2010

Please see our last post about this comet:

http://remanzacco.blogspot.com/2010/05/comet-c2009-r1-mcnaught-animation.html

by Ernesto Guido & Giovanni Sostero

Friday, September 4, 2009

Update about the unusual activity of 217P/LINEAR

We post here an update about the unusual activity of 217P/LINEAR (see our previous post http://bit.ly/32cXXc ). We did not use invasive image processing routines (as the Larson-Sekanina filtering) in order to minimize the risk of introducing any artefact in the images. In the panels you will find only ordinary grayscale palette images, azimuthal median subtractions and 1/r theoretical coma subtractions, in order to enhance inner coma details:

2009 Aug. 15, David Cardenosa:

2009 Aug. 20, Michael Jaeger:

2009 Aug. 21, David Cardenosa:

2009 Aug. 22, David Cardenosa:

2009 Aug 22, Guido-Sostero:

2009, Sept.3, Paul Camilleri:

Central condensation evolution during the rise of the phenomena:

From what is possible to see from the above images, we might bracket the rise of the event between Aug. 20 and Aug. 21. It had a rather quick evolution (matter of hours) and then it settled down in some days.

We would exclude a foreshortening effect. In our opinion we have witnessed a transient phenomena that has interested the nucleus of the comets and/or its surroundings for a relatively short time. Currently (i.e. after a couple of weeks from the event) the comet seems to have recevered to its pre-something occurence.

We are grateful with the authors of the images.

by Giovanni Sostero & Ernesto Guido

Tuesday, September 1, 2009

New comet discoveries: C/2009 Q5 (McNaught) & C/2009 Q4 (Boattini)

IAU Circular nr.9070, issued on 2009, Sep. 01, announces the discovery of a new comet by R. H. McNaught, named C/2009 Q5 (McNAUGHT). It was found on Aug. 31 in the course of the Siding Spring Survey with the 0.5-m Uppsala Schmidt telescope.

After posting on the Minor Planet Center's 'NEOCP' webpage, other observers have noted the cometary appearance of this 17magnitude object.

We have been able to confirm this object remotely, through the GRAS network, using a scope located in Mayhill (NM): on 2009, September 01.3, co-adding of 15 unfiltered exposures, 120 seconds each, obtained by means of a 0.25-m, f/3.4 reflector + CCD, shown a compact coma about 12 arcmin in diameter and a broad tail nearly 20" long in p.a. 255 deg.


Our image is available here:





This is an image of C/2009 Q5 by M. Jaeger:



The preliminary orbit for comet C/2009 Q5 (McNaught) indicates perihelion on Mar. 11, 2010, at about 1.6 AU:



This is the 50th comet discovery for Robert McNaught.

Congratulations to Rob for this great achievement.


--------------------------------------------------------------------------------

IAU Circular nr.9069, issued on 2009, Aug. 31, announces the discovery of a new comet by A. Boattini, named C/2009 Q4 (BOATTINI). It was found on Aug. 26 in the course of the Catalina Sky Survey with the 0.68-m Schmidt telescope. Magnitude at the discovery 18.9.

The preliminary orbit for comet C/2009 Q4 (Boattini) indicates perihelion on Nov. 1, 2009, at about 1.5 AU:



This is comet discovery number 10 for Andrea Boattini.


by Ernesto Guido & Giovanni Sostero

Saturday, August 29, 2009

New Comet P/2009 Q1 (HILL)

IAU Circular nr.9067, issued on 2009, Aug. 29, announces the discovery of a new comet by R. E. Hill, named P/2009 Q1 (HILL). It was found on Aug. 27 in the course of the Catalina Sky Survey with a 0.68-m Schmidt telescope.

After posting on the Minor Planet Center's 'NEOCP' webpage, the object's cometary appearance has been noted by several observers.


We have been able to confirm this object remotely, through the GRAS network, using a scope located in Mayhill (NM): on 2009, August 28.3, co-adding of 15 unfiltered exposures, 120 seconds each, obtained by means of a 0.25-m, f/3.4 reflector + CCD, shown a diffuse coma almost 15 arcmin in diameter and a broad tail 50" long in p.a. 255. The total magnitude m1 has been established to be about 18 (unfiltered CCD).


Our image is available here:



An Mpec (including pre-discovery Spacewatch observations on Aug. 16) with preliminary orbital elements and an ephemeris has been issued too:


The first orbit indicates for comet P/2009 Q1 (HILL) a perihelion on July 19, 2009, at about 2.8 AU.

by Ernesto Guido & Giovanni Sostero

Saturday, August 22, 2009

Unusual aspect of Comet 217P

Prompted by an alert note posted today by David CardeƱosa on [Comets-ml] about the unusual aspect of 217P/LINEAR he recorded in his images of this comet obtained on 2009, Aug 22.1, we performed some follow-up about 217P remotely, through a 0-25-m, f/3.4 reflector + CCD (near Mayhill, NM).

Co-adding of 12 unfiltered exposures, 120 seconds each, obtained on 2009, Aug. 22.4, confirms the presence of a highly structured coma. The central condensation appears sharp, and elongated in a West-East direction. A spiralling arclet about 1.5 arcmin long is emanating from the central condensation in clockwise direction.



We notice the presence of two distinc tails: one about 1.8 arcmin long in PA 245 deg, and a second one, about 2 arcmin long in PA 236 deg.

Our image is available here:


We notice that the current aspect of 217P, is striking similar to that of comet 73P-fragment B, at the time of its repeated outburst/splitting events occured in May 2006, e.g.:


Our Team recovered this comet on March 2009:


by Ernesto Guido & Giovanni Sostero

Friday, August 21, 2009

Unusual asteroid 2009 QY6

M.P.E.C. 2009-Q32 , issued on 2009 Aug. 20, annunced the discovery of an intriguing object: 2009 QY6.


It was picked-up on Aug. 17 with the 1.0-m f/2.15 reflector + CCD of the Lincoln Laboratory ETS team (NM), while it was moving at about 1.2"/min in the morning sky, through the constellation of Aries.

This object has an extremely peculiar orbit (a= 7.35 AU, e= 0.72, i= 137 deg, P= 20.0 years, as for 2009, Aug. 21 MPC website), very similar to that of a comet.

We performed some follow-up of 2009 QY6 while it was still listed in the NEO-CP website (labelled as "BP85104") from the Castelmartini Obs (MPC#160) on 2009, Aug. 19.0, and from the RAS Observatory (MPC#H06) on Aug. 19.4 and 20.4.

In all our stacks, we were consistently unable to identify any cometary feature on this object. Down to the limit of our seeing condition, we always obtained a FWHM profile of 2009 QY6 that was virtually undistinguishible compared to that of nearby field stars having similar brightness.

Stack from Castelmartini Obs.:


Stacks from RAS-Mayhill:


According to its preliminary orbit, this curious object might well be a "Damocloid" (http://en.wikipedia.org/wiki/Damocloid_asteroid), a few kilometers in diameter. It will reach its perihelion on 2009, OCt. 1, at about 2 AU from the Sun, and it's well worth to keep 2009 QY6 under close scrutiny, in order to check any arise of residual degassing.

Ernesto Guido, Giovanni Sostero, Enrico Prosperi and Paul Camilleri

Wednesday, August 19, 2009

Recovery of comet P/2002 S1 = P/2009 L18 (SKIFF)

CBET nr.1913, issued on 2009, Aug. 18, announces our recovery of P/2002 S1 = P/2009 L18 (SKIFF).

Our quest for this faint (magnitude about 20 at the time of recovery) periodic comet, started about two months ago, when we had several attempts to locate it in the southern costellation of Indus, by means of the remotely-controlled Skylive-Grove Creek main telescope (a 0.35-m, reflector + CCD located near Trunkey, NSW, Australia).

Finally we found it on 2009, June 15.6, about 1.7 arcmin northeast of the ephemerids position, and nearly 1.3 magnitudes fainter than predicted.

We performed a second night of follow-up on Jun. 17.6, however at that time the comet was projected over a field star, so we couldn't find it. Afterwards we had a row of bad weather, moonlight interference, personal problems, ect, that prevented us to perform a second night of astrometry, until Aug. 18.6, when we successfully imaged again P/2002 S1 through the same instrumentation. At that time the comet was about 1.8 arcmin northeast of ephemerids, nearly 1.5 magnitudes than predicted. On both observing runs, we found the comet of starlike aspect, without any appreciable coma and/or tail.

Our last image of this comet is available here:


According to CBET nr.1913, this object will reach its perihelion (q~ 2.4 AU) on 2010, Aug. 15. The ephemerids generated at the Minor Planet Center website inform us that P/2009 L18 (SKIFF) will reach its maximum brightness at perigee, on the beginning of next November 2010 (about magnitude 17).

Its last astrometric report before our recovery was performed on 2003 Apr. 07.89 by Peter Birtwhistle, from the Great Shefford Observatory (MPC#J95).

Giovanni Sostero, Ernesto Guido, Paul Camilleri and Enrico Prosperi

Comet C/2009 P2 (BOATTINI)

IAU Circular nr.9063, issued on 2009, Aug. 18, announces the discovery of a new comet by Andrea Boattini, named C/2009 P2 (BOATTINI).

It was found in the within Pegasus, with the 0.68-m schmidt of the "Catalina Sky Survey" on 2008, Aug 15.4.

Afterwards this object has been posted on the NEO-CP with the ID code of "9P1083D", in search of follow-up observations. Then, several astrometrists provided positive feedbacks about its cometary nature.

We first picked up this object on 2009, Aug. 17.4 remotely, from the Mayhill (NM) station of the Global Rent a Scope network. Unfortunately, of the 10 unfiltered exposures, 120-sec each we obtained through a 0.25-m, f/3.4 reflector + CCD, only a few were usable, because the object was merging with a field star. Under those circumstances, we could only obtain an astrometric position, with no clues about its nature because in our stacking we had not enough signal/noise to discriminate if it was an asteroid or a little comet.

We were more lucky on Aug. 18.3, when we were able to secure 20 unfiltered exposures, 120-sec each, by means of the same instrumentation. After careful image processing, it was clear to us that the object was not showing a stellar aspect: comparison of its FWHM profile with that of nearby field stars, was consistently showing higher values; the reason of this difference was the presence of a tiny coma, about 8 arcsec in diameter, with a slight elongation toward south-west.

Our image is available here:


Preliminary orbital elements were published on M.P.E.C. 2009-Q1


according to the data published so far by the Minor Planet Center, this object is moving along a parabolic (e=1), retrograde (i= 164 deg) orbit, with a perihelion at about 6 AU, that will be reached in July 2010. At about that time, it will reach a maximum magnitude of m1 about 17.4.

by E. Guido, G. Sostero, P. Camilleri, E. Prosperi

Tuesday, August 18, 2009

NOVA OPHIUCHI 2009

Cbet No. 1910 issued on 2009, August 17th announces the discovery by Koichi Itagaki of a possible nova (mag 10.0) on his unfiltered CCD survey frames taken on Aug. 16.515 UT using a 0.21-m f/3 reflector.

The nova position:

R.A. = 17h38m19s.68, Decl. = -26d44'14".0 (equinox 2000.0)


An image of the nova (by T. Greiner):


Nova Ophiuchi 2009 has been confirmed spectroscopically by various observers with the BAO 1.01-m telescope on Aug. 17.6 UT, in the course of the BAO Summer School and Japan Space Forum.

U. Munari et al. reports on Cbet No. 1912 that medium-resolution CCD spectrogram (0.06 nm/pixel; range 540-670 nm) was obtained on Aug. 17.83 UT with the 1.22-m telescope of the Asiago Astrophysical Observatory showing a quite-red spectral energy distribution and the very wide profiles of the emission lines.

"The colors, the rapid decline, and the velocity of the ejecta suggest that N Oph 2009 is a highly reddened outburst occourring on a massive white dwarf, not dissimilar from the U-Sco type of recurrent novae. A search in plate archives for missed previous outbursts could pay dividends".

To this end see also this interesting article appeared this morning on Arxiv:

"Discovery of a Second Nova Eruption of V2487 Ophiuchi"



By Ernesto Guido

References:

(subscription required for Cbet)

Sunday, August 16, 2009

New Comet C/2009 P1 (GARRADD)


Cbet No. 1908 issued on 2009, August 15th announces the discovery by G. J. Garradd of a new comet: COMET C/2009 P1 (GARRADD). The discoverer describes this comet as a tailless object with an approximately circular coma 15".


We have been able to obtain follow-up observations of this object while it was posted in the NEO-CP, from mpc code E16 by mean of a 0.35-m f/6 reflector + CCD. Our image:

According to the first and very preliminary orbit, comet C/2009 P1 (Garradd) has perihelion on Aug. 10, 2011, at about 1.3 AU.


If this preliminary parabolic orbit will be confirmed, this comet may reach at least 8 magnitude in the summer of 2011.


by E. Guido, P. Camilleri, G. Sostero, E. Prosperi

References:


Saturday, August 8, 2009

NOVA SAGITTARII 2009 No. 3

Cbet No. 1899 issued on 2009, August 07th announces the discovery by K. Nishiyama and F. Kabashima of a possible nova (magnitude at discovery 7.7) in Sagittarius on two 60-s frames on Aug. 6.494 and 6.495 UT using 105-mm f/4 lens + unfiltered CCD.

The Nova position:

R.A. = 18h07m07s.67, Decl. = -33d46'33".9 (equinox 2000.0)

Independently the same nova has been discovered by All Sky Automated Survey (ASAS) with a telephoto lens 200/2.8,
diameter 70 mm + CCD + Johnson V filter.

G. Pojmanski, D. Szczygiel and B. Pilecki of Warsaw University Astronomical Observatory reported ASAS discovery on vsnet-alert 11369. According to ASAS images, the new object was V=7.78 on August 06, 2009.

Asas light curve and images are available here:


Nova Sagittarii 2009 no. 3 has been confirmed spectroscopically as a nova by M. Fujii (Fujii Bisei Observatory, Okayama, Japan). The object shows Balmer series emission lines and Fe II emission lines.

The FWHM of Halpha emission is 2300km/sec:



by Ernesto Guido

References:


Sunday, August 2, 2009

Three new comets discovered


Three new comets have been discovered in the last few days:

C/2009 O2 (Catalina) on July 27, 2009

Preliminary orbital elements from the Minor Planet Center ( http://bit.ly/aPGCz ) assumes its orbit as parabolic, with an inclination of 108-deg. Perihelion will be reached on Mar. 24, 2010, at r about 0.70 AU from the Sun. This comet is expected to reach a maximum magnitude of about 9, at its perihelion.


C/2009 O3 (Hill) on July 29, 2009

We have been able to confirm this object while it was posted in the NEO-CP, both from mpc code H06 & 160.

Co-adding of 6 unfiltered exposure, 120 seconds each, obtained remotely near Mayhill (NM) on 2009, July 30.4 through a 0.25-m, f/3.4 reflector + CCD showes that this object to be a comet with a small, compact, coma nearly 5 arcsec in diameter with a tail 30 arcsec long in PA 225 image.

Our image:


Preliminary orbital elements from the Minor Planet Center ( http://bit.ly/kggTy ) assumes its orbit as parabolic and indicates perihelion already on Apr. 21, 2009, at about 1.9 AU.



C/2009 O4 (Hill) on July 30, 2009


Preliminary orbital elements from the Minor Planet Center ( http://bit.ly/vlPkm ) assumes its orbit as parabolic and indicates perihelion on Dec. 1, 2009, at about 2.9 AU.


All 3 comets have been found in the course of the Catalina Sky Survey. According to COCD website now the total of comet discoveries is 73 for Catalina and 15 for Hill.

by Ernesto Guido


References:

IAUC 9057 (Subscription required)
IAUC 9058 (Subscription required)
IAUC 9059 (Subscription required)

Tuesday, July 21, 2009

Nasa images confirm Jupiter impact!!!

Following the alert by Australian amateur astronomer Anthony Wesley, professional astronomers have been able to confirm the impact nature of the new dark spot appeared on July 19th on the surface on Jupiter.

See our previous post for more information:



The clue arrived from near-infrared image of the upper atmosphere above the impact site:

"An impact would make a splash like a stone thrown into a pool, scattering material in the atmosphere upwards. This material would then reflect sunlight, appearing as a bright spot at near-infrared wavelengths"

"Our first image showed a really bright object right where that black scar was, and immediately we knew this was an impact," astronomer Glenn Orton says. "There's no natural phenomenon that creates a black spot and bright particles like that."


Image captured on July 20, 2009, by NASA's Infrared Telescope Facility in Mauna Kea:




Image captured by the Keck II telescope in Hawai:


Here you can see an image of the discoverer of the impact dark spot, Anthony Wesley, with his telescope:



by Ernesto Guido


References

Monday, July 20, 2009

New Impact on Jupiter?

Starting from July 19, 2009 rumors appeared all over the astronomical internet community about a possible new impact on Jupiter.

A new dark spot was just discovered by Australian amateur astronomer Anthony Wesley on Jupiter surface. He noticed it on his images taken with his 14.5" newtonian aroud 1300UTC of 19th July. The same area was imaged by Wesley 2 days before and the dark spot wasn't there. This new dark spot shares a strikingly resemblance with the impact marks made on Jupiter by comet Shoemaker-Levy 9 when it crashed into the giant planet in 1994 (just in these days is recurring the 15th anniversary of the impacts of the comet Shoemaker-Levy 9 fragments on Jupiter, dated 16-22 July 1994).

Here you can see the Wesley images of the new dark spot:




For comparison a SL9 impact image dated 1994:



After the announcement on Wesley website, other amateur astronomers have been able to confirm the dark spot. Anyway the shape alone of this dark spot, was not enough for the impact nature to be confirmed. In favour of the impact hypothesis: the location of this new dark spot, near the Jupiter South Pole where usually storm activity is minor and the fact that the location was featureless in the images of 2 days earlier.

But a more resolutive proof is the Near-IR or methane-band imaging. Material from an impact should be stratospheric and hence should appear bright at these wavelengths.

A confirmation that arrived few hours ago. Leigh Fletcher, planetary scientist at Pasadena, was twittering live about this event and the work he and his colleagues were doing with IRTF:

Some of his messages:

"We're now almost certain it's an impact event, extremely exciting!"

"Working with Glenn Orton, we're acquiring spectra of the impact site
with IRTF/SpeX. Very bright in refl. sunlight, high altitude
particles"

"The impact site on Jupiter is rotating into view on the IRTF, we're
imaging with Spex, have acquired spectra. VERY bright feature!!"

"New instrument for looking at Jupiter impact site: IRTF/MIRSI,
probing thermal characteristics of the impact location."

"This has all the hallmarks of SL-9 in 1994 (15 years to the day!). High altitude particulates, looks nothing like weather phenom"


While this is a note appeared on mpml mailing list by Franck Marchis (Astronomer at University of California at Berkeley):

"We observed Jupiter with the Keck telescope and its NIR camera and we confirm that the feature is unusual because of its brightness in the CH4 band. It is most likely a impact explosion in the upper atmosphere of Jupiter. We are processing the data right now and will beginning the analysis"

While waiting for an official release by professional astronomers confirming the impact event definitively, it's interesting to report this comment by astronomer Alan Fitzsimmons:

"it is no surprise that if an asteroid or inert comet had hit Jupiter recently we might not know about it. A 1-km diameter asteroid or inactive comet at that distance is roughly magnitude V=25 to 26 (100 thousand million times fainter than Jupiter itself), much too faint to pick up. SL-9 was only found because it had activated through tidal disruption - we now know that it had probably been in orbit around Jupiter since the 1930’s, but no-one picked it up because of its faintness"

Congratulations to Anthony Wesley for his finding!!!


by Ernesto Guido

References:




Thursday, June 18, 2009

New Comet P/2009 L2 (YANG-GAO)

IAUC Circular No. 9052, issued on 2009, June 16, announces the discovery by Rui Yang and Xing Gao of a new comet on several survey images taken by Gao in the course of the Xingming Comet Survey at Mt. Nanshan using a Canon 350D camera (+ 10.7-cm f/2.8 camera lens).

We have been able to confirm this object while it was posted in the NEO-CP, both from mpc code H06 & E16.

Co-adding of 10 unfiltered exposures, 60 seconds each, obtained remotely near Mayhill (NM) on 2009, June 16.4 through a 0.25-m, f/3.4 reflector + CCD showed a coma about 40 arcsec in diameter, and a tail nearly 90 arcsec long toward PA 245 deg.

Here you can see our confirming images:

http://bit.ly/lc1J6

http://bit.ly/KNrdz

An Mpec with a preliminary orbital elements and an ephemeris has been issued too:

http://www.cfa.harvard.edu/mpec/K09/K09M05.html

The first preliminary orbit for comet P/2009 L2 (Yang-Gao) indicates perihelion already on May 19, 2009, at about 1.3 AU. The period is about 6.6 years.

This is the third amateur discovery in 2009, and the second for the Xingming Survey.

Congratulations to our chinese fellow observers for this new find.

by Ernesto Guido, Giovanni Sostero, Paul Camilleri & Enrico Prosperi

Friday, May 22, 2009

Recovery of 107P/Wilson-Harrington = (4015) Wilson-Harrington

MPECs 2009-K24 & 2009-K27, issued on 2009 May 21 & 22, reports our recovery of comet 107P/Wilson-Harrington, obtained over three consecutive nights: on 2009, May 19 and 20 from Mayhill (NM) through a 0.25-m, f/3.4 reflector + CCD (details on image):

http://tinyurl.com/r83bdq

and on 2009, May 21, by means of the 0.61-m f/10 reflector + CCD of the Sierra Stars Observatory, Markleeville (CA).

This object has an interesting story, since its cometary nature (a tail without coma) has been reported only once, at the time of its discovery, so its activity appears to be rather irregular:

http://cometography.com/pcomets/107p.html
http://www.aerith.net/comet/catalog/0107P/index.html
http://en.wikipedia.org/wiki/107P/Wilson-Harrington
etc.

Also in our current stackings, the object appears perfectly stellar, with no trace of any coma or tail.107P/Wilson-Harrington was last observed on 2007, March 13 by the Mt. Lemmon Survey.

Ernesto Guido, Giovanni Sostero, Paul Camilleri & Enrico Prosperi

Monday, May 18, 2009

Update about comet 19P/Borrelly

Further follow up performed by the undersigneds with the same instrumental set-up of our previous report (but with 600-sec total integration time) on 2009, May 17.21, shows that the secondary condensation (or knot) that has been reported on comet 19P/Borrelly (see our previous post) has significantly weakened, with an aspect extremely diffuse and elongated compared to our previous observation of May 15.21.

On May 17.21 the optocenter (difficult determination) of this feature had a displacement of about 4 arcsec in PA 301 with respect to the central condensation of 19P/Borrelly.

Our image is available here:

http://tinyurl.com/qnvpvw

Giovanni Sostero, Paul Camilleri, Enrico Prosperi & Ernesto Guido

Friday, May 15, 2009

Secondary condensation on 19P/Borrelly

Prompted by an alert note of Bernhard Haeusler, posted in the newsgroup [Comets-ml] on May 11, 2009 about a possible secondary "condensation" in 19P/Borrelly, we performed some follow-up about this comet.

Images obtained by the undersigneds on 2009, May 15.21 with the 0-61-m Cassegrain + CCD of the Sierra Stars Observatory (Maarkleville, CA) confirms the presence of a tailward, diffuse, secondary condensation or "knot", placed about 4.7 arcsec in PA 301 from the primary central condensation. This feature is nearly 1.5 magnitude fainter compared to the central condensation itself. Image processing techniques (azimuthal median subtraction of the inner coma) enhances the visibility of this detail.

Our image is available here:

http://tinyurl.com/qendnd


Comparing the offset data posted in the same blogspot by B. Hausler (May 7: 13 arcsec in PA 310) and F. Kugel (May 10: 8 arcsec PA 305), this feature apparently approaches the central condensation; however some foreshortening effect might be under course, also considering the fact that, on about 2009 June 5th, Earth will cross the orbital plane of this comet.

Paul Camilleri, Enrico Prosperi, Giovanni Sostero & Ernesto Guido

Wednesday, May 13, 2009

Possible Nova in Centaurus 2009

Following an alert note posted today by Grzegorz Pojmanski in the vsnet-alert newsgroup about a possible nova in Cen, on 2009 May. 13.57 we performed some follow-up of this object remotely through a 0.25-m, f/6 Ritchey-Chretien + CCD, from the RAS Observatory (Moorook, Australia).

We can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 8.6 (UCAC-2 Catalogue refernce stars) at coordinates:

R.A. = 13h31m15.77s, Decl. = -63o57'38".6 (equinox 2000.0; UCAC-2 catalogue reference stars).

Comparison with an Anglo-Australian Observatory Schmidt red plate (limiting magnitude about 20), obtained on 1997, Feb. 05, show that this position is nearly coincident with a field star, whose position end figures are 15s.68, 38".6, and magnitude about 15 (however, the extreme stellar crowding due to nearby field stars, makes this measurement rather difficult).

Our image of this transient is available at the following URL:

http://tinyurl.com/qlbesc

by Ernesto Guido and Giovanni Sostero

Monday, April 20, 2009

Recovery of comet P/2002 LZ11 (LINEAR) = P/2009 H1 (LINEAR)

IAU Circular No. 9039, issued on 2009 Apr 19, announces our recovery of P/2002 LZ_11 (LINEAR), now designated P/2009 H1 (LINEAR); it was last observed in January 2004 (MPC code #372, Geisei).

After several frustating and unsuccessful tryings due to moonlight interference and stellar crowding (the searched comet was in Sgr) we initially picked-up P/2002 LZ11 on 2009, Apr. 17.45 through a remotely controlled telescope of the GRAS network (details on image):


In our stacking the comet was located about 4 arcmin to the East-Northeast of the ephemerids position: co-adding of 25 unfiltered exposures, 120 seconds each, through a 0.25-m, f/3.4 reflector + CCD, revealed the presence of an extremely compact coma, about 12-arcsec in diameter, and a short tail nearly 25-arcsec long toward West.

We tried further follow-up on April 18 from the same site and from the Skylive-Grove Creek Obs. (MPC #E16), however our efforts were hampered due to the star crowding and to the unsuitable observing conditions (a magn. 19 comet seen through amateurs instrumentation, needs a pretty good sky).

Hopefully we were more lucky using the 0.37-m, f/14 reflector + CCD of the Iowa Robotic Observatory near Sonoita, AZ ((MPC# 857) over the same night: co-adding of 20 unfiltered exposures, 120 seconds each, showed the presence of a tiny coma about 8-arcsec in diameter, with a faint extension toward West (two bright field stars were interfering with the detection of the small tail we had recorded well the day before). Our image is available here:



According to the orbital elements published so far by the Minor Planet Center website (http://tinyurl.com/cqnamw), perihelion will occur on March 2010, with the comet at 2.4 AU from the Sun. This Jupiter-family comet moves along an elliptic orbit in about 7 years, having a semi-major axis of 3.7 AU, eccentricity of 0.35 and an inclination of 11.5 deg.


Ernesto Guido, Giovanni Sostero, Paul Camilleri and Enrico Prosperi 

Friday, April 17, 2009

Recovery of comet P/2003 H4 (LINEAR) = P/2009 F7 (LINEAR)

IAU Circular No. 9038, issued on 2009 Apr 15, announces the recovery P/2003 H4 (LINEAR) = P/2009 F7 (LINEAR) by the LINEAR team and the undersigneds; it was last observed in August 2003.

The Lincoln Near Earth Asteroid Research facility: 


picked-up P/2003 H4 on 2009, March 31 during a single-night observing session. We indipendently found the return of this object on 2009 April 15.60 through one remotely controlled telescope of the "Skylive" network, located at Grove Creek (near Trunkey, Australia). 

In our images (stacking of 30 unfiltered images, 60-seconds each, with a 0.35-m f/7 reflector + CCD), the comet showed a diffuse coma about 15-arcsec in diameter, with a central condensation, having m2 about 19.6.

The recovered comet was about 8 arcmin East, South-East to the ephemerids positions, located in Hydra.

Here you can found our recovery image of April 15, 2009:


Afterwards we performed some further follow-up from different observing sites and instruments, that confirmed the aspect of this object. 

Like the Iowa Robotic Observatory (MPC# 857) 20x60 stack of images, obtained on 16 April 2009:


or the GRAS stacking, obtained on the same night under good seeign conditions (details on image):



According to the orbital elements published so far by the Minor Planet Center website (http://tinyurl.com/c8k56q), perihelion will occur on June 2009, with the comet at 1.7 AU from the Sun. This Jupiter-family comet moves along an elliptic orbit in 6.1 years, having a semi-major axis of 3.3 AU, eccentricity of 0.49 and an inclination of 18 deg.

We would like to thank the Grove Creek-Skylive staff for their kind support during this recovery.

by Giovanni Sostero, Enrico Prosperi, Ernesto Guido & Paul Camilleri 

Tuesday, April 7, 2009

New Comet 2009 F6

IAUC Circular No. 9034, issued on 2009, April 6, announces the discovery by R. D. Matson of a new comet from analysis of ultraviolet SWAN-SOHO images obtained on 2009, Mar. 29, 31, Apr. 1, 3, and 4.

We undertaken a first try to locate this object from the private observatory of one of us on (about) Apr. 6.1; however we were unsuccessfull, due to some hardware problems with the telescope.

Afterwards we were able to confirm the existence of this comet remotely, through the GRAS network, using a scope located in Mayhill (NM): on 2009, April 6.5, co-adding of 10 unfiltered exposures, 60 seconds each, obtained by means of a 0.25-m, f/3.4 reflector + CCD, shown a diffuse coma about 2.5 arcmin in diameter, with a sharp central condensation about 20 arcsec in diameter. The magnitude of the central condensation was measured to be at about 14 (unfiltered CCD), while the total magnitude m1 has ben established to be about 11 (unfiltered CCD).

Stacking a total of 20 minutes exposure time, through equalization of the histogram, we can trace a coma diameter of nearly 5 arcmin; image enhancing techniques (azimuthal median subtraction and 1/r theoretical coma subtraction) show the presence of a short extension toward North-East, emanating from the central condensation (hint of a tail, or elongation of the coma?).

Our image is available here:

http://tinyurl.com/co95my

At the time of this writing, no orbital elements of this comet has been published by the Minor Planet Center. A preliminary calculation, performed by the undersigneds running through FindOrb the observation currently available at the the NEO-CP webpage, gives the following (approximate) orbital solution:

q= 1,3 AU, e= 1, Incl.= 85.5 deg, Peri.= 129.5 deg, Node= 279 deg.



UPDATE (07 April 2009, 14:00 UT)

IAUC Circular 9035 has been released and the new comet is now officially designated C/2009 F6 (YI-SWAN).

According to this IAUC, Dae-am Yi (Yeongwol-kun, Gangwon-do, Korea) has contacted H. Yamaoka, on March 28, informing him about his discovery of a possible comet through a Canon 5D camera + 90-mm telephoto lens. The available astrometry indicate that this is the same object of comet 2009 F6. So, the double denomination.

An Mpec with a preliminary parabolic orbital elements and an ephemeris has been issued too:

http://www.cfa.harvard.edu/mpec/K09/K09G21.html


UPDATE (07 April 2009, 21:00 UT)

Our image of comet C/2009 F6 (YI-SWAN) rendez-vous with open cluster NGC 7789:

http://tinyurl.com/d7h7aj

by Ernesto Guido, Giovanni Sostero & Paul Camilleri

Monday, March 30, 2009

Recovery of P/2001 MD7 (LINEAR) = P/2009 F3 (LINEAR)

IAU Circular No. 9031, issued on 2009 Mar 20, announces the recovery of comet P/2001 MD_7 = COMET P/2009 F3 (LINEAR) by the undersigneds; it was last observed in April 2002.

We picked up this object on 2009 Mar 17, 18 and 20 through a couple of remotely controlled telescopes, located in New Mexico and Australia. The comet appeared as a pale glow, magnitude about 18, nearly 15 arcsec in diameter.

The recovered comet was very close to the ephemerids positions, however its detection has been a little problematic, because it was rather low in the morning sky just before twilight, located in a rich star field in Sgr. We took several nights of observations to locate it, fighting with clouds and moonlight interference.

Here you can see our image of March 22, 2009:

http://tinyurl.com/czgnts

According the orbital elements published by the Minor Planet Center, perihelion will occur in September 2009, with the comet at 1.25 AU from the Sun; at that time P/2009 F3 (LINEAR) will reach about magnitude 12. This object moves along an elliptic orbit in 7.9 years, having a semi-major axis of 3.97 AU, eccentricity of 0.68 and an inclination nearly 13.5 deg.

We thanks the Mayhill-GRAS and Grove Creek-Skylive staff for the kind support they provided us for this tricky recovery.

by Ernesto Guido, Giovanni Sostero & Paul Camilleri

Sunday, March 15, 2009

New comet C/2009 E1 (ITAGAKI)

M.P.E.C. 2009-E68  issued on 2009 March 15, announced the discovery by K. Itagaki of a new comet:


We performed some follow-up of this object while it was posted in the NEO-CP.

Since the candidate was too low to be imaged from the Remanzacco Observatory (MPC #473), on 2009, Mar. 15.1 we connected to the GRAS network, and imaged it remotely from Mayhill (NM), details on image:


The initial stacking produced a trailed image of the central condensation, because the expected proper motion was slightly off. After some trials, we found the suitable speed and PA able to produce a sharp image of the comet.

Stacking our frames (co-adding of 30 unfiltered exposure, 30 seconds each) we noticed an obvious comet, with a central condensation having about magnitude 14.6 (unfiltered R), a bright inner coma, having a diameter of about 1.4 arcmin, and faint external halo nearly 4 arcmin in diameter, slightly elongated toward South-West. The total magnitude m1 we measured was about about 11.0 (unfiltered R).

From the preliminary orbital elements published by the MPC:


we understand that this comet moves along a parabolic, retrograde, orbit (i= 126 deg, q= 0.6 AU). Perihelion will be reached in the beginning of next April 2009, with m1 about 10. Unfortunalety comet ITAGAKI will stay at small elongation from the Sun, so it will be a difficult object to be observed.

K. Itagaki found it from his private observatory of Takanezawa-Tochigidi with a 0,2-m f/3, reflector + CCD camera at (about) 09h UT on 2009, March, 14.

Congratulations to Itagaky-san for his nice gift: there are still some opportunities for dedicated amateur comet catchers, in spite of the professional surveys!

by Ernesto Guido, Giovanni Sostero e Paul Camilleri 
(AFAM, Osservatorio di Remanzacco)

Wednesday, March 11, 2009

Foreshortening effects on C/2007 N3 (LULIN)

Comet C/2007 N3 (LULIN) was a nice show in late February this year, when it passed relatively close (nearly 0.42 AU, on Feb. 24th). At about its perigee, another phenomena occurred: its phase angle reached a minimum value, then it quickly started to grow-up again. Nearly simultaneosly we witnessed an abrupt change in the appearance of the comet, due to the consequent foreshortening effect: the ion tail, in a matter of hours, switched from North-West to South-East.

Possibly another, less cospicuous, change in comet's LULIN aspect may be under course: according to our follow-up, some effects of the foreshortening change seems to be readily visible also in a series of images we secured from various sites & through with different scopes, in the past few weeks.

As you may notice from the following panels, the prominent feature (kind of "fan" structure) originating from the central condensation toward South-West (i.e. at about PA 220 deg), plus a secondary one, toward North-East (i.e. at about PA40 deg) that was reported by several observers, visible till March 2nd, now seems to be over:

March 11th: http://tinyurl.com/acq7wr

March 2nd: http://tinyurl.com/d8bnfc

Februaty 27th: http://tinyurl.com/cpslxs

February 19th: http://tinyurl.com/bgt6yd

More data need to be secured to definitely clarify the situation, however at a first glance we have the impression that this might be a foreshortening effects as well. Apparently, the changing geometry really plays a strong role, when interpreting the inner coma details sometimes reported on comets (alleged fans, jets, etc.).

by Giovanni Sostero, Ernesto Guido, Paul Camilleri & Virgilio Gonano

Monday, March 9, 2009

Curious coma-tail of C/2007 Q3 (Siding-Spring)

Recently we imaged C/2007 Q3 (Siding Spring), remotely with a "Skylive" scope from Grove Creek (Australia):

http://tinyurl.com/amgcvn

details on picture.

Through image processing, the comet show a funny effect: at low contrast, an asymmetric coma is seen, about 45 arcsec in diameter, with an obvious elongation toward (about) East (PA 90 deg). In high contrast, a broad tail, nearly 80 arcsec long, became obvious; but it points toward South-West, at about PA 230 deg (i.e., in nearly opposite direction)!

Further image processing, capable to extract possible inner coma features (azimuthal median subtraction, 1/r theoretical coma subtraction) confirms the presence of an asymmetric coma, with a possible feature exing toward East, North-East, developing in a counterclockwise direction.

Preliminary photometric analysis of our frames, show a total m1 magnitude of about 13, while the sharp central condensation shine at m2 about magnitude 15 (unfiltered CCD).

Comet C/2007 NQ3 (Siding-Spring) moves along a parabolic orbit, whose perihelion will be reached in October 2009, at 2.2. AU from the Sun.

Updated orbital elements and ephemerids are available in the Minor Planet Center's Website:

http://tinyurl.com/bgbme8

by Giovanni Sostero, Ernesto Guido & Paul Camilleri

Monday, March 2, 2009

Asteroid 2009 DD45 Close Approach

2009 DD45, an "Apollo" type asteroid, has been discovered on 2009, Feb. 27th, with the "Siding Spring Survey" 0.5-m Uppsala Schmidt + CCD:

Few days later, on 2009, Mar. 2nd, about 13h40m UT, it made a close approach with Earth, passing only 72,000 Km away (i.e. 1/5th of the Earth-Moon distance, and about twice the height of geostationary satellites).

When we shoot our image, a couple of hours before its closest approach, this rock (about 35-m in diameter) was speeding at about 9 deg/hour in the southern constellation of Vela, shining at about magnitude 12. The 5 seconds exposure time was more than enough to record its trail among the field stars (details on image):

http://tinyurl.com/b7j4cd

by Paul Camilleri, Giovanni Sostero & Ernesto Guido

Friday, February 27, 2009

Changing geometry of comet C/2007 N3 (LULIN)

During the past few nights, we witnessed a dramatic change of the viewing geometry of comet LULIN: its ion tail switched its position from North-West, and is currently hidden behind the coma. However this phenomena doesn't change that much the visibility of some details within the inner coma of the comet.

Here you can find an image obtained on 2009, feb. 27 (details in caption):

http://tinyurl.com/av6q5e

Comparison with a similar image, obtained on 2009, Feb. 19:

http://tinyurl.com/bhku68

show the persistence of some asymmetries in the inner coma. In particular, a kind of "fan" toward PA200 deg, with a second, similar structure (but less evident) in the opposite direction, toward PA 20 deg. It's not clear yet the explanation of this features; what we can say at the moment, is that they doesn't seem to be artefacts (i.e. artificially generated features using image processing softwares) and that they show no significant changes in spite of the significative change of our perspective angle.

by Ernesto Guido, Giovanni Sostero and Paul Camilleri

Tuesday, February 24, 2009

Comet Lulin at its best

Today, February 24th, Comet Lulin is making its closest approach to Earth (0.41 A.U.) peaking at magnitude 5.0. After that Lulin is moving away from both Earth and the Sun, so it fades fairly quickly. 

Yesterday, Lulin was just 2 degrees south-southwest of Saturn.

Here You can see our image showing the rendez-vous between the comet and the planet:


While here there is an animation showing the motion of the comet in 5 minutes (this week the comet is moving at over 5° per day):


Because of the particular geometry between Earth, comet and Sun we see the comet Lulin showing a nice sunward pointing dust tail (antitail) along with a ion tail.

This diagram shows the geometry of Comet Lulin's tail and anti-tail:

http://tinyurl.com/djj3gm (courtesy of Paolo Berardi)


For more information and images please check also our past posts about this nice comet:



By E. Guido & G. Sostero

Friday, February 20, 2009

2008 TC3 Fragments Recovered!!!

According to an article appeared few hours ago on New Scientist website, a team of meteorite hunters, using data provided by NASA, has finally has found fragments of the asteroid 2008 TC3 plunged into the atmosphere above Sudan on 7 October 2008.

Here You can find some of the post appeared on this blog about 2008 TC3 story:

http://remanzacco.blogspot.com/2008/10/small-asteroid-2008-tc3-to-hit-earth.html

http://remanzacco.blogspot.com/2008/10/2008-tc3-animation.html

http://remanzacco.blogspot.com/2008/10/2008-tc3-update-impact-flash-imaged.html

http://remanzacco.blogspot.com/2008/11/2008-tc3-trail-imaged-over-northern.html

A photo of one of the fragments recovered can be seen in the slides of a presentation reported at a United Nations meeting discussing near-Earth object (NEO) impacts (slide number 19):

http://www.oosa.unvienna.org/pdf/pres/stsc2009/tech-25.pdf



http://tinyurl.com/dftr2m (courtesy of P. Jennisken - SETI Institute)

It seems that the discovery team, including well-know meteorite expert Peter Jenniskens, has already submitted a study about the find to a scientific journal, but no more information are available at present.

Sources:
http://www.newscientist.com/article/dn16635-found-pieces-of-space-rock-once-seen-heading-for-earth.html

http://www.oosa.unvienna.org/oosa/en/COPUOS/stsc/2009/index.html

by Ernesto Guido