Globular with a Wealth of Variables

M3
By Cyprien Pouzenc

Lying about 33,900 light years away in the constellation Canes Venatici, M3 is a globular cluster populated by about a half million stars. This cluster is notable for being rich in variable stars and also contains a relatively large number of Blue Stragglers. It provides a visual delight to the telescopic observer, as noted by Cyprien Pouzenc in this sketch from Southern France. Cyprien’s translated notes can be seen below:

Sketch done with graphite pencil on white paper.

Object : M 3
Nature : Globular Cluster
Constellation : CVn

RA : 13h 42′ 11,2″
Dec. : +28° 22′ 48″

– Date, hour, duration : 10-05-07, 22:35 TU, 9′
– Location, elevation : La Roque d’Anthéron (south of France), 175m

– No wind, T°16
– T1 (limit magnitude in UMi with naked eye : 6.17), P1 (light
pollution), S2/200x (Seeing) — all in 0 to 5 scale, 0 is the best.

– Reflector : Meade Lx90, 203/2000, F/10

Comments :
200x, H=73°; Circular cluster saw in direct vision, seemingly
fully resolved in beautiful dust of stars. A luminous central area
without important gradient is surrounded by a halo less luminous and by
a crown very grainy.

Web page of this object : http://cyprien.pouzenc.free.fr/M-3.htm
Web site : http://cyprien.pouzenc.free.fr

Clear Sky !

—
Cyp