|
Daylight test
Sometimes people ask whether stars can be seen by day. With a clear blue sky today, I decided to find out.
Using the 8" SCT, I had to algin the telescope first so that meant finding Sirius and Canopus. They were both easily visible in the finder (8 x 50).
I then had a look for Orion and found all the main stars in that region (Rigel, Bellatrix, Betelgeuse, Alnitak, Alniham & Mintaka) relatively easily.
I then came back to Canis Major and searched for progressively dimmer stars until I exceeded magnitude 6 with 14 Puppis (SAO 153796) which is mag 6.13. This was seen 30 minutes prior to sunset. One surprise was a nice double in Puppis at magnitude 5.8
Up to magnitude 4, they were fairly easily to see in the FoV (x 77) but the mag 5 & 6 stars had to be searched for. I guess one issue here different to my usual night observing is that the eye has no focus reference until it actually sights the star.
What practical use is this? Well - I don't know, unless one wanted to get the alignment sorted well prior to a night observing session. In my case, it was probably just a bit of a once-off challenge.
I would be interested to hear if others have taken on a similar challenge.
Chris
|