Terry's Astronomy Thread.

[Bluearrowll]

What's in the sky tonight?
December 9, 2013

-First-quarter Moon (exact at 10:12 a.m. EST). This evening the Moon shines just under the dim Circlet of Pisces below the Great Square of Pegasus.

-Jupiter is passing just 15 arcminutes from Delta Geminorum, magnitude 3.5, this evening and tomorrow evening. That's about half a pencil-width at arm's length. (But it's not as close as Jupiter passed by the star on October 4th, while going the other way.)

-Later this month, NASA plans to point the Hubble Space Telescope at Comet ISON to see if anything remains after the comet's death plunge through the sun's atmosphere on Nov. 28th. Note to Hubble: Don't expect to see much. Amateur astronomers are already searching the comet's position and setting hard limits on the brightness of any remains. Consider this image taken on Dec. 8th by Eric Allen of the Observatoire du Cégep de Trois-Rivières in Champlain, Québec. The position of the comet-had it survived-is circled. "I unfortunately have to say that there is nothing down to about magnitude +16.5, not even a small condensation," says Allen. More information about Allen's observing techniques and image processing may be found here.

As Karl Battams of the Naval Research Lab comments in his blog on the Comet ISON Observing Campaign web site: "The evidence appears strong that at some point approaching perihelion Comet ISON likely began to completely fall apart. What remains of ISON now is going to be either just a cloud of dust, or perhaps a few very depleted chunks of nucleus. Either way, it's not going to flare up at this point and we should assume the comet's show is over."

Astro Picture of the Day:
December 9, 2013

Source:
Lovejoy continues to be an impressive camera comet. Pictured above, Comet C/2013 R1 (Lovejoy) was imaged above the windmill in Saint-Michel-l'Observatoire in southern France with a six-second exposure. In the foreground is a field of lavender. Comet Lovejoy should remain available for photo opportunities for northern observers during much of December and during much of the night, although it will be fading as the month progresses and highest in the sky before sunrise. In person, the comet will be best viewed with binoculars. A giant dirty snowball, Comet Lovejoy last visited the inner Solar System about 7,000 years ago, around the time that humans developed the wheel.