M21 (Open cluster)
R/B-band color composite image from the Second Digitized Sky Survey (DSS2), measuring 10 arcminutes across.
From Cambridge , M21 is visible in the evening sky, becoming accessible around 21:41 (EDT), 22° above your southern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 23:02, 25° above your southern horizon. It will continue to be observable until around 00:34, when it sinks below 21° above your southern horizon.
Name
M21
|
Object type
Open cluster
|
Position
Right ascension: | 18h04m [3] |
Declination: | −22°29' [3] |
Constellation: | Sagittarius |
Magnitude: | 5.90 (V) [5] |
Distance: | 1.2 kpc 3.9 klyr [2] |
Derived quantities
Absolute mag (V): | -4.50 |
Sources