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:

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).

by Ernesto Guido

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. Below the footage from a security camera in Burgersfort in the Limpopo Province:

(Credit: Christo van Graan - Burgersfort)

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

by Ernesto Guido

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.

This nova has been designated NOVA ERIDANI 2009.

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"

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

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:

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:

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

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:

(click to enlarge)

Here you can find other videos of the fireball uploaded on Youtube.

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

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:

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

by Ernesto Guido

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:

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. This 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 & Giovanni Sostero

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:

by Ernesto Guido and Giovanni Sostero

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

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 even.

by Ernesto Guido

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" team for their discovery.

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

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 confirmation image (click on it for a bigger version):

Preliminaty orbital elements and ephemerids of this periodic comet have 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 & Giovanni Sostero

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.

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 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. Click on the image below for a bigger version.

 

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

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:

The preliminary orbit for comet P/2009 S1 (Gibbs) indicates perihelion already on Jul. 25, 2009, at about 2.4 AU: http://www.cfa.harvard.edu/mpec/K09/K09S70.html

This is the 13th comet discovery for Gibbs.

by Ernesto Guido & Giovanni Sostero

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 ephemerid.

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 below:

by Ernesto Guido & Giovanni Sostero

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: http://www.cfa.harvard.edu/mpec/K09/K09R33.html

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

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:

http://tinyurl.com/myrzz5

http://tinyurl.com/lhhusa

http://tinyurl.com/la4zoe

2009 Aug. 20, Michael Jaeger:

http://tinyurl.com/l6azme

2009 Aug. 21, David Cardenosa:

http://tinyurl.com/mv5u3w

http://tinyurl.com/m7t6cf

http://tinyurl.com/nhzyam

2009 Aug. 22, David Cardenosa:

http://tinyurl.com/nwz729

http://tinyurl.com/nr5bl4

http://tinyurl.com/l5ddrc

2009 Aug 22, Guido-Sostero:

http://tinyurl.com/l2jtqz

2009, Sept.3, Paul Camilleri:

http://tinyurl.com/lyore4

http://tinyurl.com/n4vnaw

http://tinyurl.com/mvwoth

Central condensation evolution during the rise of the phenomena:

http://tinyurl.com/nqgwdd

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

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: http://www.cfa.harvard.edu/mpec/K09/K09R02.html

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: http://www.cfa.harvard.edu/mpec/K09/K09Q84.html

This is comet discovery number 10 for Andrea Boattini.

by Ernesto Guido & Giovanni Sostero

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: http://www.cfa.harvard.edu/mpec/K09/K09Q67.html

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

Unusual aspect of Comet 217P

Prompted by an alert note posted today by David Cardeñosa 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.

Arclet are temporary phenomena in the cometary coma that are related with fragmentation events of the nucleus

We notice the presence of two distinct 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

Unusual asteroid 2009 QY6

M.P.E.C. 2009-Q32 , issued on 2009 Aug. 20, announces 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.

Stacks from RAS-Mayhill:

According to its preliminary orbit, this curious object might well be a "Damocloid", 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

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

http://www.cfa.harvard.edu/mpec/K09/K09Q14.html

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

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)

http://www.cfa.harvard.edu/iau/cbet/001900/CBET001910.txt

http://www.cfa.harvard.edu/iau/cbet/001900/CBET001911.txt

http://www.cfa.harvard.edu/iau/cbet/001900/CBET001912.txt

http://arxiv.org/abs/0908.2143

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.

http://www.cfa.harvard.edu/mpec/K09/K09P54.html

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:

http://www.cfa.harvard.edu/iau/cbet/001900/CBET001908.txt (subscription required)

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:

Credit: ASAS

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:

http://www.astrouw.edu.pl/asas/ (ASAS)

http://ooruri.kusastro.kyoto-u.ac.jp/mailman/listinfo/ (VSNET)

http://www.cbat.eps.harvard.edu/ (CBAT)

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 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 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 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)

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 about this event.

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."

Below the image captured on July 20, 2009, by NASA's Infrared Telescope Facility in Mauna Kea (click on the image for a bigger version):

Below the image captured by the Keck II telescope in Hawai (click on the image for a bigger version):

Below the image of the discoverer of the impact dark spot, Anthony Wesley, with his telescope:

UPDATE - June 03, 2010

NASA's Hubble Space Telescope imaged the dark spot caused by the impact of a comet or an asteroid. The first image is dated back to July 23, 2009. Other images taken in the following months showed how the dark spot changed day to day in the planet's cloud tops (click on the images below for a bigger version - Images Credit: NASA, ESA, and H. Hammel (Space Science Institute, Boulder, Colo.), and the Jupiter Impact Team).

by Ernesto Guido

References

http://www.jpl.nasa.gov/news/news.cfm?release=2009-112

http://bit.ly/oWUKk

http://bit.ly/Ktd5O

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).

Below the Wesley images of the new dark spot (click on the image for a bigger version)

For comparison below you can see a SL9 impact image dated back to 1994 (click on the image for a bigger version)

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.  Below are some of his tweets:

"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

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 image:

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

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):

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

Also in our current stackings, the object appears perfectly stellar, with no trace of any coma or tail. Comet107P/Wilson-Harrington was last observed on 2007, March 13 by the Mt. Lemmon Survey.

Ernesto Guido, Giovanni Sostero, Paul Camilleri & Enrico Prosperi