Professor Comet Report may 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 8 Bright 50° N - 45°S Early Morning McNaught 2009 K5 C 8.5 Fading 55°N - 15°N All night Machholz 2 141P PPP ~10 Steady Elongation N/A Status: Poor Wild 2 81P PPP 10.5 Fading 55°N – 75°S All Night Tempel 2 10P PPP 11.5 Bright 45°N - 75°S Morning Christensen 2006 W3 C 12 Fading 30°N – 90°S Best Morning Vales 2010 H2 PPP 12 Possibly 55°N – 55°S Best Fading Evening Wolf – 43P PPP Possibly Bright Conjunction N/A Harrington 12 Gunn 65P PPP 12.5 Steady 30°N – 85°S Morning Schwassmann 29P PPP Possibly Varies 50°N - 45°S Early – Wachmann 13 Evening Siding Spring 2007 Q3 C 13 Fading 65°N – 5°S All Night Catalina 2009 O2 C 13.5 Fading Poor N/A Elongation P/Hill 2010 A3 PPP 14 Fading 45°N - 5°S Early Evening The red designation is assigned to all comets that are of 12 th visual magnitude or brighter and are classified as the majormajor 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! 1 C/2009 R1 (McNaught) This comet could possibly become the great comet of 2010 as reports coming in from comet observers now indicate an 8 th visual magnitude brightness of this comet. R1 has just left solar conjunction and initial reports indicate that the comet is brighter than what was expected and continues to get brighter throughout the months of May and thru June. R1 is rapidly getting brighter at an ever increasing rate as it reduces its distance between itself and both the Earth and Sun. However the absolute brightness for this comet increases at an ever slower rate. Right now it is visible between the Eastern edge of the great square of Pegasus and the Eastern Fish of Pisces during the early morning hours of late spring before sunrise. Based on MPC data, this comet is expected to reach 5 th visual magnitude by late June and a maximum brightness of 4.7 during the period 3 – 8 July. However, an analysis of the light curve indicates that this comet could reach a visual magnitude range of 2 – 3, but the comet is moving eastward across the sky and enter back into solar conjunction! Currently the comet can be located between the Northeast edge of the great square of Pegasus and the Eastern Fish of Pisces during late May. As of 24 May the comet is positioned between Epsilon and Zeta Andromedae at a current distance from Earth of 1.3955 AU and a solar distance of 1.0154 AU. This means that the comet is technically now as close to the Sun as Earth is in its mean distance from our home star, but still above the plane of the ecliptic. The comet will move in a general NE direction passing north of Tau Piscium during the early morning hours of 28 May. The comet will move along the southern edge of Andromeda passing a few degrees to the SE of both Mirak ( β Andromedae) and Almach ( γ Andromedae) during the period of 28 May thru 6 June. All the while the comet will have reached a distance form Earth of 1.1823 AU and a solar distance of 0.7645 AU at an expected 7.2 visual magnitude. The comet will graze to the South of the spiral galaxy NGC 891 during the evening hours of 7 June. R1 will fly past Andromeda and move towards Perseus during early thru mid June. It will be about 2° to the NW of the open star cluster NGC 1039 by mid day of 9 June moving in a NE direction towards the northern region of Perseus. The comet will pass to the south of Melotte 20 which houses Mirfak ( α Persei) during mid June. The comet will graze by Delta Persei to its SE and then head out of the Perseus and move into Auriga by late June with a solar elongation of only 27° by 20 June! The comet will move in 2 an easterly direction to the north of Capella and then head south again towards the Sun for another solar conjunction. R1 McNaught will occult Castor at an expected visual magnitude of 4.8 during the evening hours of 4 July EDT, but it will be at a paltry solar elongation of 13° and not visible to astronomers during the mid summer. During this whole period from late June thru mid July, R1 will turn more southerly towards the ecliptic as it moves out of Gemini towards the Western edge of Cancer. All this is happening as it approaches the ecliptic while obtaining its perihelion during the time in which it will be at maximum brightness! IAU MPC Ephemeris data for C/2009 R1: Date TT RA(2000) Decl. Delta r Elong. Phase m1 m2 2010 05 24 00 38.69 +25 48.9 1.408 1.026 46.7 45.9 8.9 2010 05 29 01 04.06 +31 03.2 1.311 0.932 45.1 50.3 8.3 2010 06 03 01 37.04 +36 37.2 1.230 0.837 42.5 54.9 7.7 2010 06 08 02 20.73 +42 01.6 1.171 0.742 38.8 59.1 7.0 2010 06 13 03 17.79 +46 19.9 1.139 0.647 34.4 62.3 6.4 2010 06 18 04 26.49 +48 14.0 1.139 0.558 29.3 63.0 5.7 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 NoteNote:: 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. 3 C/2009 K5 (McNaught) This is another of McNaught’s comets that is currently well positioned in the northern hemisphere for late spring. It is currently being reported as a well condensed smudge in a good pair of binoculars when seen in fairly dark skies. K5 is believed to have reached a maximum brightness of 7.9 visual magnitude during the earlier part of May is expected to stay in the 8 – 9 range for into the first few days of June. After that it will continue to fade towards 10 – 11 visual magnitude range thru early June and then dim to 12 th magnitude before 18 July while still observable in the northern hemisphere while low in the night skies. K5 McNaught as of 24 May is at the northern edge of the constellation region of Cepheus having past through the main body of that constellation last month. It will move thru a line of stars stretching from HD 30338 which is a K3III star to HD 268326 and ending at HD 25007 with a spectral classification of G8III + A6V. The stars have a visual magnitude of 5.07, 5.43, and 5.10 respectfully and crossing this line of stars during the evening of 24 May while moving to the ESE. The comet will then turn south heading towards Camelopardalis and will stay within eastern region of the constellation until mid July. To find the comet in northern area of Camelopardalis, look for a ‘broken – T’ shaped asterism of stars centered on HD 34351 which has a spectral type F0 at a visual magnitude of 6.74. The comet will pass just over half a degree during the late afternoon of 28 May and during that same night the comet will have to the north of HD 35783. It has the spectral type F8 at a visual magnitude of 7.69 and represents the eastern edge of the broken – T asterism. The comet will move through many non – distinguishing stars during early June, but can be found on average about 1 hr of RA to the east of open cluster Collinder 464 through early June while moving in a more SE direction.