Stars continue starry
May. 5th, 2009 12:23 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
fivemackThis is Collinder 399, on the border between Vulpecula and Sagitta, unsurprisingly called the Coathanger Cluster.
200mm f/2.8, ISO 3200, 2-second exposure; sky-glow removed and brighter stars made more visibly prominent by the protocol used in http://fivemack.livejournal.com/179278.html . Scale in the large version is about five pixels per arc-minute, in the smaller version about 80 pixels per degree.
Limiting magnitude is about 9.5 (if anyone has access to a better star catalogue than mine - YourSky only goes down to magnitude nine - and can make a better estimate of how bright the faintest visible star in the big image is, please tell me), so twenty times fainter than the naked eye can see from a perfect site, and about 250 times fainter than I can see from central Cambridge.
Below is the Beehive Cluster in Cancer, setting over a neighbour's roof, taken with roughly the same setup (ISO 1000, 2 seconds, 150mm f/2.8, contrast stretched in gimp):
If you looked at the Hubble picture of M57 as suggested in my last post, you may be amused by the image that the same setup produces of that object:
200mm f/2.8, ISO 3200, 2-second exposure; sky-glow removed and brighter stars made more visibly prominent by the protocol used in http://fivemack.livejournal.com/179278.html . Scale in the large version is about five pixels per arc-minute, in the smaller version about 80 pixels per degree.
Limiting magnitude is about 9.5 (if anyone has access to a better star catalogue than mine - YourSky only goes down to magnitude nine - and can make a better estimate of how bright the faintest visible star in the big image is, please tell me), so twenty times fainter than the naked eye can see from a perfect site, and about 250 times fainter than I can see from central Cambridge.
Below is the Beehive Cluster in Cancer, setting over a neighbour's roof, taken with roughly the same setup (ISO 1000, 2 seconds, 150mm f/2.8, contrast stretched in gimp):
If you looked at the Hubble picture of M57 as suggested in my last post, you may be amused by the image that the same setup produces of that object:
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Date: 2009-05-06 12:42 am (UTC)