Friday, September 26, 2008

COMET P/2008 QP20 (LINEAR-HILL)

The IAU Circular nr.8979, issued on 2008 Sept. 24, annouces the discovery of a new comet: P/2008 QP20 (LINEAR-HILL). This object has been picked-up in Aries by R. E. Hill through the 0.68-m Schmidt telescope of the Catalina Sky Survey on 2008, Sept.23.3, and afterwards linked by K. Smalley (Minor Planet Center) with an object discovered by the LINEAR sky survey on 2008, Aug. 25.4. Hill's discovery report describe this 18-th comet as having a well condensed coma about 6 to 12 arcsec in diameter, and a narrow tail up to 4' long in PA 250-260 deg.

After its posting on the NEO-CP, several observers confirmed its cometary nature: in general, the comments pointed to a small coma, and a tail pointing toward south-west. We performed some follow-up of this object on Sept. 24.4, remotely from Mayhill (NM), and foud a coma about 10" in diameter and a narrow tail about 30" long in p.a. 233 deg (details on image):

http://tinyurl.com/3eldrr

The preliminary orbital elements published on M.P.E.C. 2008-S48 ( http://www.cfa.harvard.edu/mpec/K08/K08S48.html ), points toward a Jupiter-family comet (a~ 3.5 AU, e~ 0.5, i~ 8 deg, P~ 6.5 years); perihelion will be reached at the beginning of November 2008, at about 1.7 AU. The maximum brightness will be reached at the end of next October, at about magnitude 17; it will mostly remain a northern object.

Updated ephemerids are available at the Minor Planet Center:
http://www.cfa.harvard.edu/iau/Ephemerides/Comets/2008QP20.html

by Ernesto Guido, Giovanni Sostero and Paul Camilleri

Monday, September 22, 2008

COMET C/2008 S1 (McNAUGHT)

IAUC nr.8977, issued on 2008, September 19, announces the discovery of a 17-magnitude comet by R. H. McNaught about 2.5 deg. northwest of Antares (Alfa Scorpii). It was described by the discoverer, and afterward by several astrometrists that perfermed confirmatory follow-up, as having a coma about 8 to 30-arcsec in diameter, with an extension (tail or elongated coma) 10 to 20-arcsec long toward North-East.

We performed some follow-up of this object with a 0.25-m, f/6 reflector + CCD from the Moorook Observatory (Australia) on 2008, Sept. 18.5, founding an obvious coma nearly 12-arcsec in diameter:

http://tinyurl.com/4eq4je

Preliminary orbital elements, published on M.P.E.C. 2008-S10, assume a parabolic orbit, with inclination of about 18 deg, and perihelion on 2008, Sept. 21 (r~ 1.35 AU). The comet is now receding from both, Earth and Sun, and will get progressively fainter. Updated ephemerids are available at the Minor Planet Center website:

http://www.cfa.harvard.edu/iau/Ephemerides/Comets/2008S1.html

by Ernesto Guido, Giovanni Sostero and Paul Camilleri

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

New Comet C/2008 R3 (LINEAR)

IAUC nr.8973, published on 2008, September 8th, announces the discovery by the LINEAR sky survey, of a new comet, named C/2008 R3 (LINEAR). It has been found in Hercules on 2008, Sept. 7 at about magnitude 18; several observers performing its follow-up, found signs of cometary activity (coma diameter ranging from 8 ti 13-arcsec, tail of 15 to 20-arcsec toward PA about 130-deg).

Initially we observed it with the 0.30-m f/5.8 reflector at Trunkey, N.S.W., Australia, on Sept. 8.44-8.48, obsering a small coma about 12-arcsec in diameter. Further observations were obtained on 2008, Sept. 8.8 through a 0.45-m, f/4.4 reflector + CCD at the Remanzacco Observatory (Italy), where a deep stacking showed the presence of a coma and a broad tail toward South-East.

Here we post an animation (12 frames, 5 minutes exposure time each) obtained during such observing session:

video


Preliminary orbital elements from the Minor Planet Center (http://tinyurl.com/4577dd) assumes its orbit as parabolic, with an inclination of nearly 43-deg. Perihelion will be reached in November 2008, at r about 1.9 AU from the Sun. This comet is expected to reach a maximum magnitude of about 17, at its perihelion.

by P. Camilleri, G. Sostero and Ernesto Guido

Friday, September 5, 2008

Comet C/2008 R1 (GARRADD)

IAUC Circular No. 8969, published on 2008, Sept.4, informs that Gordon Garrad discovered a comet in the southern constellation of Grus, named C/2008 R1 (GARRADD). This object has been found on 2008, Sept. 2.5 through the 0.5-m schmidt at the Siding Spring observatory (Australia).

We performed some follow-up of this object remotely, from the Grove Creek-Skylive Observatory (Trunkey, Australia) on 2008, Sept. 2.7, by means of a 0.35-m, f/6.7 reflector + CCD.Our stacking of 24 unfiltered exposures, 120 seconds each, showed a tiny coma nearly 8 arcsec in diameter, elongated toward PA30 deg (details on image):

http://tinyurl.com/5rpan4

According to the preliminary orbital solution published on M.P.E.C. 2008-R22, this comet moves along a parabolic orbit, with i= 19 deg, and q= 1.7AU. Perihelium will be reached on November 2008. For te rest of this year it will mostly be a southern object, and the maximum magnitude is not expeted to be higher than 18.Updated ephemerids are available at the Minor Planet center website:

http://www.cfa.harvard.edu/iau/Ephemerides/Comets/2008R1.html

by Paul Camilleri, Giovanni Sostero and Ernesto Guido

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

Wednesday, September 3, 2008

Possible Nova in Sco

Following the posting on the Central Bureau's unconfirmed-objects webpage about a possible nova in Sco, on 2008 Sep. 3.45 we performedsome follow-up of this object remotely, from Moorook (Australia),through a 0.1-m, f/5 refractor + CCD.

We can confirm the presence of a relatively bright object (unfilteredmagnitude about 9.6) at coordinates:

R.A. = 17h57m32s.93, Decl. =-30o43'10".3 (equinox 2000.0; UCAC-2 catalogue reference stars).

Comparison with an archive UK-Schmidt Red plate (obtained on 1992,June 03) show no counterparts at this precise coordinates; a nearbyfield star, with position end figures: 32s.95, 08".1, has magnitudeabout 18.

Our confirmation image is available here:

http://tinyurl.com/5w5e8u

by Ernesto Guido, Giovanni Sostero and Paul Camilleri

Tuesday, September 2, 2008

Possible Nova in Centaurus

Following an alert note of Grzegorz Pojmanski, Dorota Szczygiel and Bogumil Pilecki of Warsaw University Astronomical Observatory, about their discovery of a possible nova in Centaurus at coordinates: A.R.= 14h 35m 03s; Decl.= -64o 06.4', through the ASAS3V instrument of The All Sky Automated Survey, we performed some follow-up of this object, remotely from the Skylive-Grove Creek Observatory (Trunkey, Australia).

Our LBVRI images, obtained on 2008 Sep. 2.4 to 2.5, through a 0.3-m, f/6 reflector + CCD, shows the presence of a relatively bright counterpart at coordinates:

R.A. = 14h35m02s.54, Decl. = -64o06'20".0 (equinox 2000.0; UCAC-2 catalogue reference stars).

Comparison with an archive Poss-2 Red plate (obtained on 1991, Jul.17) and with a Poss-2 Infrared plate (obtained 1981, Mar.02) show the presence at this coordinates of an extremely faint optical counterpart, at the detection limit of the plate. These are the results of our multicolor photometry (comparison stars HIP_71437 and HIP_71400): 2008, Sept. 2.39: B=9.54, V=8.63, R=8.03, I= 7.42; Sept. 2.46: B=9.69, V=8.70, R=8.10, I= 7.60 (accuracy about 0.05 magn. in each color). An estimation by P. Camilleri (Hurstville, NSW, Australia) performed on 2008, Sept. 2.48, through a 20x80 binocular, provides a visual magnitude of 8.4.

Our image is available here:

http://tinyurl.com/5mcxrs

by Giovanni Sostero, Ernesto Guido and Paul Camilleri