M81 & M82: Galaxy Pair (Ursa Major) |
M81 and M82 were the first galaxies I observed with my 10-inch Meade Starfinder equatorial Newtonian. The star hop may not seem particularly easy but is definitely worth the effort. I begin at 1.8 magnitude Dubhe in the bowl of the Big Dipper. A triangular arrangement of 5th and 6th magnitude stars is about one finder scope field (4 degrees) to the northwest. Slewing another 4 degrees north, an elongated triangular grouping of 6th magnitude stars comes into view. This asterism points the way to M81 and M82, about 3.5 degrees west. M81 is usually first to come into view. Both can be seen in an 8X50 finder. M82 is about half-a-degree north of M81. |
M81: Spiral Galaxy (Ursa Major) RA: 09h 55.6m / DEC: +69° 04'.0 Instrument: 10-inch Starfinder |
The sketch at left is based on a 129X view in the 10-inch. M81 appears as a 24'x13' oval nebulosity with a bright, condensed nuclear region. The uneven glow around the nucleus is suggestive of this galaxy's spiral structure. Several stars are visible in the foreground of M81. Don't be fooled into thinking these are supernovae. A pair of 12th and 13th magnitude stars south of the core region are often mistaken as such. The nuclear region is surrounded by a 4'x3' core. The surrounding nebulosity appears brighter and thicker to the southwest, an indication of the galaxy's inclined orientation to our line of sight. |
M82: Irregular Galaxy (Ursa Major) RA: 09h 55.9m / DEC: +69° 40'.9 Instrument: 10-inch Starfinder |
M82 lies 36 arc minutes due north of M81. This irregular galaxy appears as an elongated 11’x4’ glow in two distinct sections. The northeast section is somewhat thicker and shorter. A v-shaped cleft is visible separating this from the longer, thinner southwest portion. Excellent seeing conditions reveal substantial mottleing in M82. |
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