I enjoyed a very nice view of C/2009 P1 (Garradd) tonight. It’s been too long since I’ve gotten out for a recreational observation. The coma was moderately condensed with distinct elongation to the southeast. Further scrutiny revealed a prominent tail about 10 arc seconds in length pointed to the southeast at a PA of 115°. The south edge of this tail had a more abrupt spine while the north edge was softer. At a northeast PA 67°, a shorter, more delicate tail drifted about 5 arc seconds from the central condensation. Overall, there was an impression of a diffuse hood draped across the northwest side of the coma.
At times, I thought I detected the slightest hint of green in the coma, but I wasn’t certain enough to include it in the sketch. The warmly colored, ninth magnitude glow of TYC1559-1174-1 decorated the north edge of the view. I looked for evidence of the comet’s motion 90 minutes later, and there appeared to be some slight drift to the northwest. However, I hadn’t plotted the star field with enough density close to the coma to estimate the apparently slow motion with enough accuracy.
OCT 31, 2011 UPDATE: I re-observed the comet the following night (NOV 1, 2011, 0330 UT) and noted motion of about 8 arc minutes to the west-northwest at a PA of about 287°.
|Subject||C/2009 P1 (Garradd)|
|Position*||Hercules: [RA: 17 37 31.2 / Dec: 18 44 35.5]|
|Size||Coma: 5 arc minute diameter
Degree of Condensation: 6
Dust tail: 10 arc minute length at 115° PA
Ion tail: 5 arc minute length at 67° PA
|Date/Time||OCT 30, 2011, 7:00 PM MST
(OCT 31, 2011, 0200 UT)
|Observing Loc.||Flagstaff, Arizona, USA – Home|
|Instrument||SkyQuest XT8 (8 inch f/5.9 Dobsonian)|
|Eyepieces/Mag.||Pentax XW10 (120X)|
|Conditions||Clear, calm, 1st quarter moon|
|*Sources||Starry Night Pro Plus 5.8; Aerith.net|