Stephen James O'Meara's Secret Sky: Twilight musings
January 2011: If you wait until the dark of night to do your observing, you're missing a lot.
November 19, 2010
|In July 2010, Sverrir Gudmundsson of Reykjavík, Iceland, decided to search the twilight for naked-eye stars about one and a half hours after sunset. He noticed that the sky surrounding 1st-magnitude Deneb (Alpha [α] Cygni), at an altitude of about 70°, appeared a much darker shade of blue than the sky around similarly bright Altair (Alpha Aquilae), at an altitude of 35°. What Gudmundsson observed is a little-known aspect of the twilight sky — one that artists and nature observers alike have long appreciated. |
You are currently not logged in. This article is only available to Astronomy magazine subscribers.
Already a subscriber to Astronomy magazine?
If you are already a subscriber to Astronomy magazine you must log into your account to view this article. If you do not have an account you will
need to regsiter for one. Registration is FREE and only takes a couple minutes.
Non-subscribers, Subscribe TODAY and save!
Get instant access to subscriber content on Astronomy.com!
- Access our interactive Atlas of the Stars
- Get full access to StarDome PLUS
- Columnist articles
- Search and view our equipment review archive
- Receive full access to our Ask Astro answers
- BONUS web extras not included in the magazine
- Much more!