Asteroid 2009 BD81 Removed from Risk List February 11, 2009
Posted by jcconwell in Asteroid, Asteroids, Astronomy.Tags: 2009 BD81, Asteroid, Astronomy
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This in from The Tracking News JPL/NASA has removed asteroid 2009 bd from the risk page, after new observations that have narrowed the impact uncertainty to exclude Earth.
Summary Risk Table for Risk Assessments Updated Today (last checks: NEODyS and JPL at 2358 UTC)
See the CRT page for a list of all objects rated recently as risks and our ephemerides page for a list of risk-listed objects under current observation.
The time horizon for JPL is 100 years from today and for NEODyS is usually the year 2090. Beginning Jan. 22nd, both are also posting impact solutions beyond 100 years for a few objects.
For the latest official risk assessments, and for explanations of the terminology, see the JPL NEO Program Sentry and NEODyS CLOMON (backup) risk pages.
| Object | Risk Monitor |
When Noted UTC |
Year | Prob Cum |
PS Cum |
PS Max |
Notes for Today’s Latest Risk | ||
| 2009 BD81 | JPLSentry | 1605 | R E M O V E D | JPL: Risk listing removed at 1549 UTC. | |||||
Comet Lulin February 11, 2009
Posted by jcconwell in Astronomy, Comets.Tags: Astronomy, comet
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Well it’s raining here in Illinois, but when it clears tomorrow, and through the month of February, a good object to look at in a small telescope is Comet Lulin . It’s even BETTER with a pair of binoculars .
Comet Lulin on February 2nd, glowing at magnitude 6.5 with tail and antitail. Click image for larger view. Paolo Candy
The comet makes its closest approach to Earth (0.41 AU) on Feb. 24, 2009. Current estimates peg the maximum brightness at 4th or 5th magnitude, which means dark country skies would be required to see it. No one can say for sure, however, because this appears to be Lulin’s first visit to the inner solar system and its first exposure to intense sunlight. Surprises are possible.
Comet C/2007 N3 (Lulin) was discovered by Quanzhi Ye, a student (age 19) at Sun Yat-sen University in mainland China, as an apparently asteroidal object on images taken by Chi Sheng Lin (National Central University, Taiwan) with a 16-inch telescope at Lulin Observatory in Taiwan on the night of July 11, 2007.
Lulin’s green color comes from the gases that make up its Jupiter-sized atmosphere. Jets spewing from the comet’s nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.
It is visible before dawn in the southern sky, as shown below and should reach peak brightness in late February and early March.
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EIU Astro 