* Astronomy

Pan-STARRS Telescope Finds New Distant Comet

The comet is expected to be brightest in February or March 2013, when it makes its closest approach to the sun. At that time, the comet is expected to be visible low in the western sky after sunset, but the bright twilight sky may make it difficult to view.
Over the next few months, astronomers will continue to study the comet, which will allow better predictions of how bright it will eventually get. Wainscoat and UH astronomer Henry Hsieh cautioned that predicting the brightness of comets is notoriously difficult, with numerous past comets failing to reach their expected brightness.
Making brightness predictions for new comets is difficult because astronomers do not know how much ice they contain. Because sublimation of ice (conversion from solid to gas) is the source of cometary activity and a major contributor to a comet's overall eventual brightness, this means that more accurate brightness predictions will not be possible until the comet becomes more active as it approaches the sun and astronomers get a better idea of how icy it is.
The comet is named C/2011 L4 (PANSTARRS). Comets are usually named after their discoverers, but in this case, because a large team, including observers, computer scientists, and astronomers, was involved, the comet is named after the telescope.
C/2011 L4 (PANSTARRS) most likely originated in the Oort cloud, a cloud of cometlike objects located in the distant outer solar system. It was probably gravitationally disturbed by a distant passing star, sending it on a long journey toward the sun.
Comets like C/2011 L4 (PANSTARRS) offer astronomers a rare opportunity to look at pristine material left over from the early formation of the solar system.

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Source

Google earth file: Comet C2011 L4 (PANSTARRS).kmz  (17kb, kmz)

Ephemeris

 Date__(UT)__HR:MN     R.A._(ICRF/J2000.0)_DEC  Mag

 2011-Apr-06 00:00     16 40 01.61 -17 15 29.0  19.61
 2011-May-06 00:00     16 28 10.50 -16 59 39.1  19.33
 2011-Jun-05 00:00     16 11 29.39 -16 39 31.5  19.11
 2011-Jul-05 00:00     15 55 21.22 -16 26 12.9  18.96
 2011-Aug-04 00:00     15 44 53.28 -16 32 05.0  18.87
 2011-Sep-03 00:00     15 42 26.18 -17 02 48.8  18.79
 2011-Oct-03 00:00     15 47 39.65 -17 55 14.2  18.69
 2011-Nov-02 00:00     15 58 48.83 -19 01 04.4  18.53
 2011-Dec-02 00:00     16 13 34.40 -20 11 13.8  18.30
 2012-Jan-01 00:00     16 29 14.78 -21 18 39.8  17.98
 2012-Jan-31 00:00     16 42 38.25 -22 20 01.6  17.58
 2012-Mar-01 00:00     16 49 48.76 -23 15 44.0  17.09
 2012-Mar-31 00:00     16 46 05.53 -24 06 28.2  16.53
 2012-Apr-30 00:00     16 27 25.72 -24 43 56.9  15.96
 2012-May-30 00:00     15 55 13.20 -24 45 56.4  15.46
 2012-Jun-29 00:00     15 20 52.64 -24 07 29.5  15.09
 2012-Jul-29 00:00     14 58 05.67 -23 32 39.9  14.82
 2012-Aug-28 00:00     14 51 42.86 -23 48 40.9  14.54
 2012-Sep-27 00:00     14 59 40.02 -25 09 01.6  14.15
 2012-Oct-27 00:00     15 18 42.68 -27 28 46.7  13.59
 2012-Nov-26 00:00     15 46 50.47 -30 44 58.2  12.79
 2012-Dec-26 00:00     16 24 23.46 -35 11 39.8  11.67
 2013-Jan-25 00:00     17 18 12.46 -41 44 49.0  10.05
 2013-Feb-24 00:00     19 12 26.91 -52 17 43.3   7.59
 2013-Mar-26 00:00     00 45 42.49 -39 00 07.5   3.98
 2013-Apr-25 00:00     02 32 18.15 +19 49 50.6   2.70
 2013-May-25 00:00     02 20 31.50 +53 22 29.7   6.68
 2013-Jun-24 00:00     01 22 50.49 +80 13 10.3   8.74
 2013-Jul-24 00:00     16 17 22.61 +73 19 17.3  10.24
 2013-Aug-23 00:00     16 13 53.95 +53 53 31.0  11.55
 2013-Sep-22 00:00     16 36 28.39 +40 28 06.1  12.69
 2013-Oct-22 00:00     17 04 33.70 +32 03 06.1  13.64
 2013-Nov-21 00:00     17 33 49.95 +27 24 56.4  14.41
 2013-Dec-21 00:00     18 01 37.40 +25 42 35.8  15.03
 2014-Jan-20 00:00     18 25 19.52 +26 21 15.0  15.52
 2014-Feb-19 00:00     18 41 57.72 +28 50 49.5  15.90
 2014-Mar-21 00:00     18 48 05.51 +32 33 59.6  16.21
 2014-Apr-20 00:00     18 40 25.25 +36 32 35.1  16.48