Discovered by Hodierna before 1654.
Independently redeiscovered by William Herschel in 1783.
The Tau Canis Majoris cluster, NGC 2362, was one of the discoveries of Giovanni Battista Hodierna, which he published in 1654. Nevertheless, as these observations were forgotten until their rediscovery in the early 1980s, this cluster escaped its rediscovery until it was eventually found by William Herschel on March 4, 1783 as his second discovery, and cataloged by him as H VII.17 based on his measurement of March 6, 1785.
Open cluster NGC 2362 contains about 60 stars, and with 25 million years, is quite young; it is still associated with nebulosity. The brightest star is Tau Canis Majoris, which is of magnitude 4.39 and spectral type O8 (Sky Catalog 2000). As it is the brighter component of a a spectroscopic binary, the mass of the system could be estimated at 40 to 50 solar masses. If, as it appears, this star is actually a member of this cluster at 5,000 light years distance, it is one of the most luminous supergiants known, at about absolute magnitude -7, or 50,000 solar luminosities.
The Sky Catalog 2000 classified this cluster as of Trumpler type I,3,p,n, taking into account that it is associated with a huge but faint diffuse nebula, which is 1.5 x 5 degrees in extension ! However, Burnham states that there's no nebulosity in the immediate neighborhood; this may be blown away by the enormous stellar wind of the young stars, above all Tau CMa. Note: This image cropped due too severe reflection artifact on right side of image, artifact still apparent through main star, cause unknown
Nice star colors Trevor.
Do you use a field flattner?
I only ask because the stars in the left hand top corner are elongated.
It could also be that something is not square or misaligned.
nice object... has good potential for your FOV. Nice contrast and colour in this image, shame about the reflections and elongated stars.
Odd reflections/whatever. I've only had rings like that when I've had dew on the scope or fog on the ccd or something on a filter in between. not sure why you have such a strong diagonal line in addition to the usual 4 though?
Don't know where it came from their is one right through the star and another larger reflection too the right which I worked out
Only thing I can think off was that I was using an Orion OAG which was borrowed (for a try) and although I couldn't get it too focus with my OSSAG I left it in the image train and the reflection may have be due the prism in the OAG
Hey Rod thanks for picking up this older thread did this one again recently using a QHY8 OSC CCD camera comparison with less data only 40 minutes in 4 frames in this one
