Professor Comet Report June 2010 Current status of the predominant comets for 2010 Comets Designation Orbital Magnitude Trend Observation Visibility (IAU(IAU(IAU-(IAU --- Status (Visual) (Lat.) Period MPC) McNaught 2009 R1 C 5 Bright 50° N - 5°N All Night McNaught 2009 K5 C 9 Fading 50°N - 20°N All night Tempel 2 10P PPP 10 Bright 50°N - 75°S Early Morning Wolf ––– 43P43P43P PPP ~111111 Bright Conjunction N/AN/AN/A Harrington Wild 2 81P PPP 11.5 Fading 50°N – 75°S Evening Christensen 2006 W3 C 12 Fading 20°N – 90°S All Night Gunn 65P PPP 12.5 Steady 40°N – 90°S Best Morning Schwassman 29P PPP ~13 Varies 25°N – 40°S Early –Wachmann Evening Vales 2010 H2 PPP 13 Possibly 50°N – 60°S Early Fading Evening Siding Spring 2007 Q3 C 13.5 Fading 50°N - 0°S All Night Machholz 2 141P PPP ~14 Fading Conjunction N/A The red designation is assigned to all comets that are of 12 th visual magnitude or brighter and are classified as the major comets . All remaining comets that are possibility at 12 th visual magnitude or fainter are given the blue designation and are classified as the minor comets! The green designation is assigned to comets to far south to be seen in the continental United States. The orange designation is for comets 12 th visual magnitude or brighter lost in the daytime glare! 1 C/2009 R1 (McN(McNaught)aught) This comet is now becoming very bright and visible in the early morning hours before sunrise with visual magnitude reports indicating that this comet is now at 5 th magnitude. The comet will continue to brighten rapidly and quite possibly reach a visual magnitude of 4.7 by early July in accordance with the predictions set forth by the MPC. However, recent analysis of the photometry data obtained from the brightness of McNaught R1 show the comet reaching 2 nd or 3 rd visual magnitude during the time period of 30 June thru 2 July. The comet has been reported even from one early visual sighting from the George Observatory as a bright, glowing, greenish – blue coma. Most visual reports have given estimations for the coma size to be between 5 – 10 arcminutes with one report indicating a photographic 12 arcminute size for the coma. There are two tails extending out from the Coma in a ‘V – shaped’ pattern with a shorter dust tail extending out with an arclength equal to the coma and a long, skinny ion tail extending 5° from the Coma! The ion tail was first reported back on 6 June and the dust tail was first identified on 13 June; it has been referred to as ‘an apple on a stick’! This is the 51 st comet to be discovered by the British-Australian astronomer Robert H McNaught on 9 September 2009 using the Uppsala Schmidt telescope at the Siding Spring observatory in Australia. This is a non periodic comet that is expected to leave the solar system permanently, so get out and observe the comet while it is still possible. Currently the comet is in the northern region of Capella which rises in the morning sky about a couple of hours before dawn. As of 23 June the comet was about 11m 41s of RA to the West and just less than 1.25° to the North of Menkalinan ( β Aurigae) which neighbors to the East of Capella. This places the comet at a distance of 1.1791 AU from Earth and a solar distance of 0.4688 AU, but the solar elongation is now at 23°. The comet will graze by Menkalinan to its North by 0.49° during the early afternoon of 24 June. Previously the comet did fly through Perseus grazing to the southeast of the open star cluster NGC 1245 during the period of 12 – 13 June. The comet is now poised to fly to the Eastern region of Auriga and fly just south of another open star cluster NGC 2218. This comet should become visible around 3 am in the morning CDT of 29 June about 45s of RA to the East and 42’ 38” of Dec. to the South of the cluster. However, the solar elongation will have been reduced to 18°. 2 The comets perigee will be increasing with the distance at 1.2492 AU the early morning CDT of 29 June while the solar distance decreases to 0.4150 AU. The comet is expected to reach its perihelion on 2 June at a solar distance predicted to be a mere 0.405 AU just placing it outside of Mercury’s orbit. McNaught R1 will have obtained a solar elongation of less than 14° making it impossible to see in the later morning hours around sunset. During this period the comet will continue to move in a SE direction across the morning sky in the northern region of ‘The Winter Hexagon’ and cross into the northern boundary of the constellation of Gemini the early evening of 2 July when the comet will be predominantly lost in the morning glare. The comet will afterwards be in Gemini with the Sun for the month of July occulting Castor between 9 – 10 PM CST on 4 July after approaching perihelion. McNaught will be in Cancer from 8 – 23 July crossing into Eastern fish of Pisces with a solar elongation of 15° with the Sun in Cancer. For the foreseeable future the comet will be placed in Pisces moving southeasterly until crossing into Antlia on the last of August by then the comet will have faded to 11 th magnitude! IAU MPC Ephemeris data for C/2009 R1: Date TT RA(2000) Decl. Delta r Elong. Phase m1 m2 2010 06 23 05 37.00 +46 44.8 1.171 0.480 24.0 59.6 5.2 2010 06 28 06 36.84 +42 00.7 1.231 0.424 18.8 50.7 4.7 2010 07 03 07 20.69 +35 08.7 1.305 0.405 14.2 37.9 4.7 2010 07 08 07 50.73 +27 30.3 1.382 0.430 10.9 26.7 5.0 2010 07 13 08 11.73 +20 04.7 1.454 0.489 10.3 21.9 5.7 2010 07 18 08 27.57 +13 16.4 1.521 0.570 12.2 22.1 6.5 2010 07 23 08 40.53 +07 08.3 1.584 0.660 15.2 23.8 7.2 2010 07 28 08 51.84 +01 35.8 1.646 0.754 18.4 25.2 7.9 2010 08 02 09 02.13 -03 26.9 1.707 0.850 21.6 26.1 8.5 2010 08 07 09 11.78 -08 05.0 1.767 0.945 24.7 26.6 9.0 2010 08 12 09 20.99 -12 22.8 1.826 1.039 27.5 26.8 9.5 2010 08 17 09 29.89 -16 23.6 1.886 1.131 30.2 26.7 9.9 2010 08 22 09 38.56 -20 10.3 1.945 1.222 32.7 26.5 10.3 2010 08 27 09 47.08 -23 44.8 2.004 1.311 35.0 26.2 10.7 2010 09 01 09 55.47 -27 09.0 2.063 1.399 37.2 25.9 11.0 3 Note: See ephemeris data terminology below . Date: Month and Year using the standard Gregorian calendar. TT: Terrestrial Time (Day of the Month) as a substitute for the astronomical Julian date. RA(2000): Right Ascension based on the Epoch J2000 (longitudinal coordinate for the celestial sky) measured in hours and minutes. Decl.: Declination as measured in degrees and arcminutes. Delta: The distance from Earth measured in AUs (1 AU = 1 Astronomical Unit = 92 955 807 mi = 149 597 871 km as the mean distance between the Earth and Sun). R: The solar distance as measured in AUs. Elong: Solar elongation which is the angle of separation between the observed object and the Sun as measured across the night sky as measured in degrees. Phase: Phase angle between the Sun, the celestial object, and the observer on the surface of the Earth. Also known as the Sun – Object – Observer angle. m1: The visual magnitude of the celestial object as observed on the surface of the Earth at sea level. m2: The nuclear magnitude which is the visual magnitude of the false nucleus within the coma as seen by an observer here on Earth at sea level. 4 C/2009 K5 (McNaught) This is another of McNaught comet with the latest reports showing a decent smudge with a reported visual magnitude of 8.3, so it is visible in binoculars. In photographs it shows a ghostly, mostly turquoise-like color with a faint tail only visible in exposure images. It will continue to be visible in the Northern hemisphere for quite a long time until it will eventually fade out visually around autumn and being quite low in the sky for the month of July. K5 McNaught as of 23 June is moving through an inauspicious area of the eastern region of Camelopardalis heading east towards the bright, irregular spiral galaxy NGC 2403 which has a visual magnitude of 8.5. This galaxy is a member of the Messier 81 group which overlaps into Ursa Major; home of the big dipper asterism. The comet will be positioned about 11m 8s of RA to the West and 1.18° to the South of NGC 2403 during the favorable evening hours on 28 June.