Stn 15 in Canis Majoris


 
William Schart
Star: Stn 15 in Canis Majoris
Date & Time: 21, January, 2002
From 10:00 pm CST.
Seeing: ~ 6 <1-10 Seeing Scale (10 best)>
Location of site: Killeen, TX, USA.
Site classification: Suburban
Sky darkness:  <Limiting magnitude>
Temperature: ~ 50ºF
Telescope: Celestar 8" SCT
Magnification: 80x, 120x and 200x 

 

Quite a challenge for a variety of reasons: tight, dim and right smack dab in the    middle of M41!.  I popped in the mid power and scanned around a bit, looking at the dimmest stars I could find and much to my surprise actually found this.
 
There are severak chains of stars radiating out from a central core of the cluster, and this pair is located just south and west of this core. Although dim, it still was readily seen and easily split - in fact, once I knew where it was, I went back to low power and could still find and split it.
 
 
 
Stuart Clough
Star: Stn 15 in Canis Majoris
Date & Time: 24.01.02 2200 - 22:55 UT
Seeing: 6+ <1-10 Seeing Scale (10 best)>
Location of site: Huddersfield A.S. Observatory
Lat 53° 37' 20". Long 01° 50'  25"W.
Site classification: Moorland.
Sky light polluted to East & North. 
Sky darkness: 4.2 (U Mi) <Limiting magnitude>
Temperature: -2º C
Conditions: Cloudless sky. Wind - 2 to 5 kts NNW.
Telescope: Orion Optics UK GX250 10"  f4.8
Mount: Vixen GP
Eyepieces:   20 mm Plossl, 9mm Ortho. Celestron Ultima x2 Barlow
Magnification: x60, x133, x267
   
Once M41 was in the eyepiece at x60, this double was surprisingly easy to identify courtesy of Skymap Pro. SMP shows it at the NE corner of a trapezium of stars which has another in the longer (southern) side. This asterism shows up well in the eyepiece STN15 is also its dimmest corner; this even amongst the briliance of the open cluster field.
   
Splitting it proved rather harder. I needed x267 to be sure and yet the split could afterwards be seen at x133. Colour was fairly difficult to determine as well. I made both stars white with just a hint of yellow.