After making some other early morning observations on January 28, 2009, I turned the telescope on Comet Lulin. Astronomical twilight was threatening, and I needed to move quickly. The view was much better than earlier in the month. The coma appeared brighter and larger and both ion and dust tails appeared longer. The dust tail appeared to be about 12 arc minutes in length at a PA of 100°. It also appeared heavier on its southern side. The ion tail was still more difficult and appeared to be about 8 arc minutes in length at a PA of 280°. The coma took an elongated appearance, stretching in the direction of the two opposing tails. It was very slightly tinted green. The pseudo-nucleus appeared as a thicker knot of brightness at the center and I would rate the degree of condensation as 6.
I took a couple minutes to attempt a more attentive magnitude estimate. With my 32 mm Plössl, I defocused at low power and compared it to a couple nearby stars. The comet appeared brighter than HIP 75532 (vMag 7.74) and fainter than 28 Librae (vMag 6.15). It was a bit closer to 28 Librae in magnitude, so I would estimate the comet at 6.8 magnitude. That's a significant difference from my rough estimate earlier in the month, but it still makes for a great, bright telescopic comet.
If you are observing the comet with a telescope under skies that are even slightly compromised, the tails will likely be very difficult to see. Under excellent conditions at Sunset Crater National Monument this morning, they were still very subtle. The coma, however, is readily visible and should still provide a nice view of the comet even if the tails don't show up. I'm still looking forward to its appearance at opposition in February when it will swing by at a reasonable hour of the night. Check The Skyhound Site for a current finder chart and be sure to look this comet up!
[NOTE: Sketches, a photograph, and detailed report of my February 20, 2009, observation of this spectacular comet can be found here: C/2007 N3 (Lulin) FEB 20, 2009.
|Subject||C/2007 N3 (Lulin)|
|Position*||Libra: [RA: 15:24:27.4 / Dec: -17:48:52]|
|Size||Coma: 6 arc minute diameter|
Degree of Condensation: 6
Ion Tail: 12 arc minutes at 280°
Dust Tail: 8 arc minutes at 100°
|Brightness*||~ 7.8 vMag|
|Date/Time||JAN 28, 2009, 6:00 AM MST|
(JAN 28, 2009, 13:00 UT)
|Observing Loc.||Flagstaff, AZ - Home|
|Instrument||Orion SkyQuest XT8 Dobsonian|
|Eyepieces/Mag.||Pentax XW 10 (120X)|
|Conditions||Clear, calm, cold|
|Transparency||Mag 7+ NELM|
|*Sources||Aerith.net; Starry Night Pro Plus 5.8|