New Comet: P/2013 T2 (SCHWARTZ)

Cbet nr. 3676, issued on 2013, October 22, announces the discovery of a new comet (discovery magnitude ~18.8) by M. Schwartz on CCD images obtained with the 0.41-m f/3.75 Tenagra III astrograph. The new comet has been designated P/2013 T2 (SCHWARTZ).

We performed follow-up measurements of this object, while it was still on the neocp. Stacking of 16 R-filtered exposures, 50-sec each, obtained remotely from MPC code F65 (Faulkes Telescope North) on 2013, October 16.4 through a 2.0-m f/10.0 Ritchey-Chretien + CCD (operated by Las Cumbres Observatory Global Telescope Network), shows that this object is a comet: sharp central condensation surrounded by a coma about 6" in diameter.

Below our confirmation image. Click on it for a bigger version.

M.P.E.C. 2013-U18 (including prediscovery Catalina Sky Survey data from Sept. 14.4 UT, when the magnitude was given as 17.8-18.6) assigns the following elliptical orbital elements to comet P/2013 T2: T 2013 June 20.65; e= 0.53; Peri. = 342.52; q = 1.60;  Incl.= 9.36

by Ernesto Guido, Nick Howes & Martino Nicolini

Update on Comet 168P/Hergenrother

Our team performed follow-up observations of comet 168P/Hergenrother on 2012, Oct. 22.4, remotely through the 2m, f/10 Ritchey-Chretien + CCD of Faulkes Telescope North (Haleakala) under good seeing conditions, and a scale of 0.3"/px. Comet 168P has recently undergone an outburst with its magnitude increasing from ~14-15 to magnituide ~9.5. For more info about the recent outburst of this comet, see our previous post here.

Recent observations posted on comet-images ml were showing a "cloud" of material trailing the nucleus in the anti-solar direction. In our image (stacking of 9 x 30-second exposures) is visible an unresolved and diffuse trail about 6" long and 3" wide in PA145. Click on the image for a bigger version.

Below you can see a graph showing recent magnitude estimates of comet 168P.  Click on the image for a bigger version.

Credit: Seiichi Yoshida

by Giovanni Sostero, Nick Howes, Alison Tripp & Ernesto Guido

Follow-up on 168P/Hergenrother bright phase

According to reports issued by a number of observers to several astro-forums, comet 168P/Hergenrother is currently experiencing a bright phase: over the course of several nights, it increased in brightness by several magnitudes, reaching a total visual magnitude of approximately 8. We performed some follow-up on it remotely, on 2012 Sept. 26 and Oct. 3, through the 2.0-m f/10.0 Ritchey-Chretien + CCD + Bessel R filter of the Faulkes Telescope South, at Siding Spring (click on the image below for a bigger version).

Inspecting our stacked images obtained on Sept. 26, the comet shows an obvious  central condensation, measuring nearly 3" across; the total coma was traced to a  diameter of about 1.7'. On Oct. 3, the central condensation grew to 8" and the  total coma diameter was nearly 3'. It's interesting to notice how, apart the growing of the central condensation  size, also its appearance changed, appearing pretty sharp on Sept. 26, and a bit "fluffy" on Oct. 3.

Subtracting the two images (after normalization of the stackings) of Sept. 26  from Oct. 3, the evolution of the central condensation became obvious. To some  extent, the difference might be due to a slight change in the perspective angles  (e.g. its phase angle passed from 10 to 13 deg), however we consider that a part  of what we see in the panel, is a genuine evolution of the central condensation  due to its active phase (click on the image below for a bigger version).

The photometric data supports the observed evolution: our afrho data on Sept. 26  shows a peak of about 670 +/- 100 cm at 2230 km from the photocenter, while on  Oct. 3 we measured an afrho of 1210 +/- 150 cm peaking at a radius of about 3000 km from the photocenter.  This seems to indicate a two-fold increase of the afrho  activity within the central condensation in a matter of a week, as well the  apparent recession of the activity peak from the central condensation. A change in the photometric profile of the coma is also obvious, from the comparison of the two panels, with the Oct. 3 graph significantly wider and less  steep, compared to that of Sept. 23.

  

By clicking on the thumbnail below you can see a short animation of comet 168P/Hergenrother on our images of 2012 Sept. 26:

So our follow-up confirms and adds scientific data to the previous reports: currently comet 168P/Hergenrother is alive and rather active.

Giovanni Sostero, Nick Howes, Alison Trip and Ernesto Guido

New Comets: C/2010 E1 (Garradd) & P/2010 E2 (Jarnac)

C/2010 E1 (Garradd)

IAU circular No. 9124 issued on 2010, March 12, announces the discovery by G. J. Garradd of a comet on CCD images taken with the 0.5-m Uppsala Schmidt telescope in the course of the Siding Spring Survey. After posting on the Minor Planet Center's 'NEOCP' webpage, other observers have noted the cometary appearance of this 18.5 magnitude object, designated C/2010 E1 (GARRADD).

We have been able to confirm this object remotely, through the GRAS network, using a scope located in Mayhill (NM): on 2010, March 12.2, co-adding of 15 unfiltered exposures, 120-seconds each obtained by means of a 0.25-m, f/3.4 reflector + CCD, show a diffuse coma nearly 10" in diameter with a a broad fan-tail about 20-arcsec long in PA 240-degrees.

Our confirming image:

The first and preliminary orbit for comet C/2010 E1 (Garradd) indicates perihelion already on Oct. 24, 2009, at about 2.6 AU.

According to COCD webpage this is the 15th comet for Garradd, and the 68th comet for the Siding Spring Survey.

P/2010 E2 (Jarnac)

IAU circular No. 9125 issued on 2010, March 13, announces that an apparently asteroidal object reported by T. Glinos on CCD images taken with a 0.64-m f/7.2 Ritchey-Chretien telescope at the Jarnac Observatory (observers listed as D. Levy, W. Levy, and T. Glinos) has been found to show cometary appearance by other CCD astrometrists. Moreover the MPC was also able to link observations of the Mt. Lemmon Survey obtained on Feb. 17, 2010.

We have been able to follow-up this object remotely, through the GRAS network, using a scope located in Mayhill (NM). Below you can see our image taken on 2010, March 13.3, co-adding of 10 unfiltered exposures, 120-seconds each obtained by means of a 0.25-m, f/3.4 reflector + CCD:

The orbit for comet P/2010 E2 (Jarnac) shows perihelion on Apr. 7, 2010, at about 2.4 AU

This is the first amateur discovery in 2010!!

by Ernesto Guido & Giovanni Sostero

Our last glance at comet 67P for a while

Periodic comet 67P/Churyumov-Gerasimenko, has greatly attracted the attention of the astronomical community, after the re-scheduling of the European Space Agency "Rosetta" mission toward it (http://www.esa.int/esaMI/Rosetta ).

After its perihelion passage, on February 28th, 2009, comet 67P has decreased its brightness, and moved toward solar conjunction. Currently it's observable again in Virgo. The main difficulty is due to its faintness (according to the ephemerids it's about m1= 19). On 2010 March 8th, we tried to perform some follow-up about this comet through the Grove Creek Observatory-Skylive network (near Trunkey, Australia). The sky conditions were good (stellar FWHM about 1.5 arcsec), with a stellar limiting magnitude on the final stacking close to 21.

At the expected coordinates, we found a faint (unfiltered CCD magnitude about 20.5) target that was and moving in good agreement with the ephemerids proper motion. In our stacking, it has a stellar aspect (details on image below. Click on the image for a bigger version):

According to the IAU-Minor Planet Center, "Dates Of Last Observation Of Comets", it was last observed on 2009 June 26, by the Observatorio Nazaret, of G. Muler (MPC#J47, Lanzarote, Spain).

Goodbye 67P, looking forward to you in May 2014, time of arrival of the Rosetta probe in yours vicinity.

by Giovanni Sostero & Ernesto Guido

The return of periodic comet 10P/Tempel

According to the ephemerids, comet 10P/Tempel is expected to reach (about) magnitude +8 next July. Currently 10P is visible (with some difficulties) in the early morning sky, pretty low in the south-east horizon, within the constellation of Serpens.According to the Minor Planet Center ephemerids, it's currently supposed to have an m1 of about 13.5; however in our images (details in the caption) this object is a modest target:

We measured it at (unfiltered Red) magnitude nearly 18, with a tiny coma of about 15 arcsec in diameter. Image enhancement techniques didn't provide any appreciable extent to the measured coma. One possibility is that, like other short period comets, 10P will develope an appreciable coma when it will get closer to the Sun (currently it's beyond the orbit of Mars, at about 2 AU from our star). Obviously we cannot rule out the hypothesis that the moonlight disturbance and/or the low altitude of the object on the horizon might have compromised the detection of a faint external coma (in spite of the fact that the sky was pretty clear and transparent).

The Afrho parameter (proxy of the dust abondance within the coma) currently is about 15 to 20 cm, like other short period comets at this distance, prior to their perihelion. Finger crossed for a neat binocular comet next summer.

Giovanni Sostero & Ernesto Guido

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

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

COMET P/2008 R6 (GIACOBINI) = 205P/Giacobini

IAUC nr.8975, issued on 2008, September 10th, announces the discovery of a 15-magnitude comet by Koichi Itagaki and Hiroshi Kaneda in the Aquarius-Aquila border. It was described having a coma diameter of about 25-arcsec, and a tail 2-arcmin long pointing toward east-southeast. We performed some follow-up of this object with the 0.45-m, f/4.4 reflector + CCD from the Remanzacco Observatory (Italy) on 2008, Sept.10.8, and with the "Skylive" 0.30-m f/6 reflector at Catania, Italy, on Sept. 10.9.Also from our stackings the coma and tail of this comet was obvious:

http://tinyurl.com/3jnbwp

Maik Meyer suggested that this apparently new comet actually was a return of D/1896 R2 (Giacobini); this link was confirmed by Nakano.Updated ephemerids are available at the Minor Planet Center website:

http://www.cfa.harvard.edu/iau/Ephemerides/Comets/0205P.html

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

Recovery of COMET P/2001 R1 = 2008 Q4 (LONEOS)

The Electronic Telegram No. 1490, published by the CBAT on September 1, announced that M. Jaeger (Stixendorf, Austria) recovered P/2001 R1 (LONEOS) on 2008, Aug. 31.08719. He described the object as having a small coma and a tail about 3' in PA 275 deg.

After reading a comment of Jaeger, posted in the newsgroup [Comets-ml] about his recovery of this comet, we performed some follow-up observations of this object, remotely from Pedara (Italy) through the "Skylive" 0.3-m, f/6 reflector + CCD. Co-adding of 14 unfiltered exposures, 120 seconds each, obtained on 2008 September 1.1, showed the presence of a small coma, nearly 10 arcsec in diameter, of about magnitude 16.8, and a tail nearly 40 arcsec long, toward PA 280 deg.

Our image is available here:

http://tinyurl.com/6zokce

G. Sostero, E. Guido, P. Camilleri and V. Gonano

Recovery of 145P/Shoemaker-Levy

M.P.E.C. 2008-R06, published on 2008, September 1, announces the recovery of 145P/Shoemaker-Levy. This periodic comet has been recovered by the Siding Spring observatory on 2008, Aug 04.55491 and 26.56107. We performed some indipendent observations of this object in the course of our own search for its recovery, along three consecutive nights (2008, Aug, 26.54329 to Aug. 28.57171) remotely, through a 0.30-m f/5.8 reflector + CCd of the Skylive-Grove Creek Observatory (Australia).

In our stackings the comet appears as a featureless, stellar object, about magnitude 19, slowly moving in the southern constellation os Microscopium.

Our mosaic is available here (details on image):

http://tinyurl.com/5mgoah

G. Sostero, P. Camilleri and E. Guido

Outburst of Comet 199P/Shoemaker

Prompted by an alert of Gustavo Muler about a possible outburst of 199P/Shoemaker, we perfomed some follow-up of this comet: we can confirm his initial observation of 2008, Aug. 3.9, that this comet is experiencing a bright phase. Co-adding of 30 unfiltered exposures, 60 seconds each, obtained on 2008, August 04.16 through a 0.25m, f/3.4 reflector + CCD (near Mayhill, NM) reveals the comet as an obvious featureless star-like object of magnitude 14.7N.

Our stack is available here (details on image):

http://tinyurl.com/6ocgp7

Image enhancement techniques show also the presence of a fain external coma, about 25 arcsec in diameter. The total magnitude m1 calculated for an aperture of 25 arcsec in diameter is about 14.6; the afrho parameter (proxy of the dust abundance within the coma) has been found to be about 800 +/- 100 cm (however it must be said that for an outbursting comet, the afrho characterization is not very meaningful because we are lacking a steady state coma behaviour).

Anyway, this is our afrho plot:

http://tinyurl.com/6yyuqq

According to Minor Planet Center "dates of last observation of comets" website, 199P was last observed by Gustavo Muler (MPC #J47) at magnitude 17.9N on 14.92 July 2008.

by Ernesto Guido and Giovanni Sostero

Recovery of Comet 59P/Kearns-Kwee

This periodic comet, 59P/Kearns–Kwee, has been recovered by us, on 2008, July 28 & 29, during the Visnjan School of Astronomy, an educational project aimed at the introduction of young talented students into the field of astronomy, organized every year by the Visnjan Observatory .

Two consecutive nights of follow up, as recommended by the Minor Planet Center, has been secured by means of the remotely controlled Skylive-4 telescope (0-30m, f/6.3 reflector + CCD) located in Catania, Italy (B40 – Skylive Observatory, Catania). 59P has been picked-up in the morning sky in Aries, significantly fainter than predicted (about magnitude 19) but very close to the expected position. In our stackings it appears as a faint dot of light, slightly wider than the nearby field stars of similar brightness. At recovery the comet was located about 2.8 AU from both, Earth and Sun. According to the Minor Planet Center, the last time of its observation was 2000, March 9 (Kuma Kogen Observatory).

Our recovery image. Click on it for a bigger version:

Comet Kearns-Kwee belongs to the Jupiter family comets; its period is nearly 9.5 years; at perihelion (March 2009) it will get as close as 2.3 AU from our star (beyond the orbit of Mars) while at aphelion it reaches 6.6 AU from the Sun (beyond Jupiter).

According to the current ephemerids, comet Kearns-Kwee will reach its maximum brightness at perigee, on November 2008: at that time it will shine at about magnitude 14, very well located (for northern observers) in the autumn constellation of Triangulum.

Updated orbital elements and ephemerids are available, as always, at the Minor Planet Center website.

by G. Sostero, E. Guido, J. Piquard, D. Bektesevic and A. Galant

Comet 6P/d'Arrest update

We imaged again periodic comet 6P/d'Arrest on 2008, July 11.96, from the Remanzacco Observatory (click on the image for a bigger version):

Image processing show the possible presence of a tiny coma, nearly 20 arcsec in diameter. The crowded stellar field hampers a sure identification of this feature, however this faint "halo" moves with the proper motion of the comet; moreover, the FWHM of the comet appears to be significantly larger compared to that of neary field stars of similar brightness, and this seems to confirm the presence of a detectable coma. The brightness of the comet has been measured at about magnitude 15 (Ru). This is still somehow fainter compared to the ephemerides (that indicates instead a visual total magnitude m1 equal to about magnitude 14), however we do know that i) CCDs magnitudes are frequently fainter than visual magnitudes and ii) the lightcurve of 6P/d'Arrest is known to show a striking asymmetric lightcurve, with lower pre-perihelion brightness. The Afrho parameter is still rather low (about 16-cm for a radius of nearly 3,000 Km at the comet distance).

Updated ephemerides are available (as always) at the Minor Planet Center website.

Giovanni Sostero and Ernesto Guido

Recovery of Periodic Comet 61P/Shajn-Schaldach

M.P.E.C. 2008-L40, issued on 2008 June 9, report the recovery of the 61P/Shajn-Schaldach (it was last observed in 2001, Dec. 11). We picked-up this faint periodic comet on 2008, June 6.4, and confirmed it on June 7,4 while it was in Pisces, by means of a remotely-controlled telescope of the R.A.S. network (details on image):

http://tinyurl.com/5okxdm

In our stackings it appears as a faint smudge of light (magnitude nearly 18). No coma or tail can be appreciated in our images, however it must be said that when we imaged it, the comet was merely 20 degrees above the horizon, nearly lost in the morning twilight, so we cannot exclude that under better observing conditions further details could be glimpsed.

61P belongs to the "Jupiter family comets" class, it completes its elliptic orbit (a~ 3.7 AU, e~ 0.43, i~ 6 deg) every 7 years. It will reach perihelion at the beginning of September 2008; however, it is not supposed to get significantly brighter than magnitude 15 (this maximum in its lightcurve will be reached at perigee, around the end of October 2008).

Updated orbital elements and ephemerids are available at the Minor Planets Center's website:

http://www.cfa.harvard.edu/iau/Ephemerides/Comets/0061P.html

by Ernesto Guido and Giovanni Sostero

Periodic Comet 6P/d'Arrest

This comet has been recovered during its current return to perhelion by J. Hobart (Kachina Observatory) on 2008 Apr. 29.37, through a 0.36-m f/11.2 Schmidt-Cassegrain + CCD, while it was slowly moving in Ophiucus at m2~ 19.5.

It is supposed to became a relatively easy telescopic object in a few months from now; perihelion will be reached on 2008, August 14, while perigee will occour few days earlier).

We performed some follow-up observations on 2008, June 9 (details on image; click on it for a bigger version):

In our stackings it appears as a faint starlike object (red magnitude close to 18) while it moves in a very rich Milky Way's star field in Aquila. Due to the star crowding, it is nearly impossible to distinguish any potential weak coma, if present.

by Giovanni Sostero & Ernesto Guido

Comet 7P/Pons-Winnecke

Prompted by a comment published on the newsgroup [Comets-ml] about a possible outburst of comet 7P/Pons-Winnecke detected by G. Muler, on 2008, May 23, we performed some follow-up of this object. Stacking of 30 unfiltered exposures, 60 seconds each, obtained remotely from Mayhill (NM) on 2008, May 25.2 through a 0.25-m, f/3.4 reflector + CCD, show that 7P/Pons-Winnecke currently has a diffuse coma nearly 25 arcsec in diameter, with a sharp central condensation.

Total magnitude m1 was measured to be R= 15.9. Preliminary afrho calculation provides a rather flat trend, with an average value of 30 +/- 5 cm.

by Ernesto Guido & Giovanni Sostero

Comet 46P/Wirtanen

Prompted by a comment published on the newsgroup [Comets-ml] about a possible outburst of comet 46P/Wirtanen reported by M. Kidger and his spanish collaborators, we performed some follow-up of this object.

Stacking of 10 unfiltered expsoures, 50 seconds each, obtained remotely from Mayhill (NM) on 2008, May 18.2 through a 0.25-m, f/3.4 reflector + CCD, show that 46P/Wirtanen currently has a very compact coma nearly 15 arcsec in diameter. The total magnitude m1 was measured to be R= 14.8. Preliminary afrho calculation provides a rather flat photometric profile with a value ranging from 90 to 130-cm for apertures diameters passing from, respectively, 10,000 to 30,000-Km at the comet distance.

by Ernesto Guido & Giovanni Sostero

Recovery of Periodic Comet 15P/Finlay

Periodic comet 15P/Finlay has been picked-up by the undersigneds on 2008, April 27.79 by means of a 0.25m, f/6 reflector + CCD (remotely, near Moorook, AU) and confirmed on 2008, April 28.70 through the same instrumentation.

Our recovery image:

 

Our astrometry:

0015P C2008 04 27.79053 22 58 27.09 -12 37 33.0 17.2 N EJ027D90

0015P C2008 04 27.79941 22 58 29.31 -12 37 19.0 17.5 N EJ027D90

0015P C2008 04 28.78638 23 02 33.02 -12 10 37.3 17.4 N EJ027D90

0015P C2008 04 28.79848 23 02 36.10 -12 10 18.9 17.5 N EJ027D90

According to the Minor Planet Center's website "Dates of last observation of comets" it was last observed on: 2002 03 30.42 14.0 T 340

W. H. Finlay (Royal Observatory, Cape of Good Hope, South Africa) discovered this comet with a 7-inch equatorial on 1886 September 26.83.

It's interesting to notice that, due to the proximity to Earth of its orbit (15P/Finlay is a Jupiter-family comet in a low inclination orbit just outside Earth's orbit), comet Finlay has been studied by several authors as a potential candidate for meteoroid delivering. D.A.J. Seargent discussed a potential relation of the famous Murchison meteorite fall with 15P/Finlay.

"Lubor Kresak identified comet 15P/Finlay as a likely source of meteor storms in the period 2004-2064. Neslusan and coworkers searched for photographed orbits in the IAU database, expecting activity around september 24, but no orbit could be linked to this comet. Martin Beech found that in the years 2001 and 2008 some meteoroids can make it toward the Earth's orbit, but Earth is not a the right time at that spot to cause a meteor outburst." (P.Jenniskens, 2006, chap. 19)

In a paper published in 1993, Z. Sekanina investigated about the orbital anomaly of 15P/Finlay (and few other periodic comets) as a result of the temporary activation of new discrete sources in cometary nuclei.

by Ernesto Guido & Giovanni Sostero

References

G. Kronk, http://www.cometography.com/pcomets/015p.html

P. Jenniskens (2006), Meteor Showers and their Parent Comets

L. Kresak (1992), Meteor Storms. Meteoroids and Their Parent Bodies

Comet P/2008 G2 (SHOEMAKER)

IAUC nr. 8939, issued on 2008, April 24, announces the recovery of P/1995 J3 = 1994k = 1994 XXVIII (Shoemaker), providing it the new designation P/2008 G2 (SHOEMAKER). It was picked up by T. Spahr, analyzing the astrometry of Apr. 10, reported by the Catalina Sky Survey (observer: R.A. Kowalsky, no comments about any potential cometary appearance) to the Minor Planet Center; linkage to further archive data of Apr.1 was provided by B. G. Marsden. The object was reported as having a magnitude of about 18.6.

We performed some follow-up of this comet on 2008, Apr. 24.9 from the Remanzacco Observatory (details on image; click on it for a bigger version):

From our stacking we have evidence of a tiny coma, nearly 10 arcsec in diameter, possibly elongated toward North-West. The measured total magnitude is about 18.5 (R unfiltered).

Perihelion of P/2008 G2 (Shoemaker) will occur in April 2009. At that time the comet will have m1 nearly 17. The maximum brightness is expected to be just half a magnitude better, in August 2009, when the comet will mostly be a southern object.

by Giovanni Sostero & Ernesto Guido (AFAM-CARA, Italy)