Year of the Comet
Comet C/2011 L4 (PANSTARRS)

PANSTARRS information

Comet C/2012 S1 (ISON)

ISON information

Ask Astro

Published: September 1, 2006
Observers often used the large refractors built in the 19th century for planetary observations. Through large telescopes like the Lick 36-inch refractor, the 26-inch U.S. Naval Observatory (USNO) refractor, and the 40-inch Yerkes Observatory refractor, magnifications of 400x to 600x were not uncommon. On nights when the seeing could be described only as "legendary," magnifications of 750x, 1,000x, and higher occasionally were employed.
Subscriber-Only Content Subscriber Only Access
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.
Login   Register
Non-subscribers, Subscribe TODAY and save!
Subscribe
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!
SEARCH SITE
Subscriber Only Access
Subscriber Only Content
Look for this icon. This denotes premium subscriber content. Learn more »
Become a Member of Astronomy.com
Register today for access to more valuable resource information.
Interact in our forums, comment on articles, receive our newsletter and much more!
Not a member?
Subscriber and Member Login
Password
Remember me