OBJECT = M15
TELESCOPE = 17.5 inch f3.23
CAMERA = ST7-E
OBSERVER = Rusty Fletcher
LOCATION = Seguin Outdoor Learning Center
DATE (Yr-Mo-Dy) = 2004-08-15
TIME (UT) = 04:06:48
TOTAL EXPOSURE = 450 sec
IMAGES STACKED = 45
Globular Cluster M15 (NGC 7078)
This cluster ranks third in the number of known variable stars. The first two are M3 and Omega Centauri. A total of 112 variables have been identified in M15. One of them is apparently a Cepheid of Type II (a W Virginis star).
M15 is perhaps the densest of all (globular) star clusters in our Milky Way galaxy. M15 was the first globular cluster in which a planetary nebula, Pease 1 or K 648, could be identified (Pease 1928, on photographic plates taken at Mt. Wilson in 1927). Leos Ondra has provided more information on this planetary nebula. In 1976 Peterson has reported a possible second planetary nebula in this globular, situated near its center, which was however never confirmed since (thanks to Leos Ondra for pointing out this fact).
Right ascension 21 : 27.6 (hours : minutes) Declination +11 : 57 (degrees : minutes) Distance 40,000 light years Visual magnitude 6.0
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