Observation Notes:
I wasn’t sure the Swelling Spiral would cooperate, but it gained enough altitude and structure started to materialize. It appeared circular with a suddenly stellar core at first glance. Next to appear was a north-south patch across the center. The north side of this bar was brightest and arced subtly to the east for about 90 degrees. The south side gradually revealed a less sharp jog to the west for about 45 degrees. I added the 2X barlow for a magnification of 240X, and was able to see a couple stars nearby. One at PA 260° appeared right at the visible edge of the galaxy’s halo.
Object Information:
M61 is about 100,000 light years in diameter and lies 60 million light years away in the Virgo Cluster. It was discovered in 1779 by Barnabus Oriani while tracking down a comet. Charles Messier encountered it 6 days later, but mistook it for a the same comet Oriani was tracking. Two days later, Messier realized the object was not moving and added it to his catalog. M61 is also cataloged as NGC 4303, CGCG 042-045, MCG +01-32-022, PGC 040001, UGC 07420, VCC 0508
Subject | M61 (NGC 4303) |
Classification | Spiral Galaxy (Type SABbc) |
Position* | Virgo [RA: 12:21:54.4 / Dec: +04:28:19] |
Size* | 6′ x 5.5′ |
Brightness* | 9.7 vMag |
Date/Time | APR 21, 2009 – 10:00 PM (APR 22, 2009 – 05:00 UT) |
Observing Loc. | Flagstaff, Arizona – Home |
Instrument | Orion SkyQuest XT8 Dobsonian (203 mm dia./1200 mm F/L) |
Eyepieces/Mag. | Pentax XW10 (120X) |
Conditions | Clear, calm |
Seeing | 5/10 |
Transparency | Mag 5.8 NELM |
*Sources | SEDS; NED; DSS; Starry Night Pro Plus 5 |
This article has been added to the Astronomy Link List.