It is currently Thu Apr 09, 2020 10:41 am

Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: Moon amongst the Hyades
PostPosted: Wed Aug 16, 2017 3:04 pm 

Joined: Sun May 11, 2008 6:11 pm
Posts: 3303
Location: Portslade, Sussex Lat 50deg 51min Long 0deg 13mins West
16th August 2017, Wednesday; Used the Endurance 12-36x50 spotting scope on a tripod from my backdoor. The sky was clear but with an occasional areole around the crescent Moon. The terminator was approaching Copernicus. Times recorded are "glance-at-the-watch" BST and not precise.
At 0250BST the Moon and Aldebaran just fitted in the lowest magnification FOV of the scope - and by 0530BST were about 1/2 that apart, but unfortunately the later predicted occultation of alpha was lost to post-sunrise murk.
However the neat asterism in the Hyades consisting of the triangle of 3-pairs of stars (including theta-1 & theta-2 and 80 & 81) were clearly note between the Moon and Aldebaran (also 75 and 85 were seen). The theta stars were very obviously going to be occulted soon by the bright limb. Before this happened, I noticed that star 71 re-appeared at about 0335BST from behind the dark limb. Finally theta-2 slipped behind the bright limb at about 0343 BT and about three minutes later theta-1 followed it. regards maf

Last edited by mike a feist on Fri Aug 18, 2017 6:34 am, edited 1 time in total.

 Profile Send private message  
PostPosted: Thu Aug 17, 2017 2:52 pm 

Joined: Thu Jun 02, 2016 11:32 am
Posts: 508
Location: New Farnley, Leeds lat 53.8N long 1.6W
Hi Mike, fascinating - I watched the occultation of pi Cap on August 6 with the Moon just a day from full and it was amazing how much the star appeared to dim in an 80mm refractor as the Moon approached it. The next night I saw the Moon rise red and partially eclipsed in twilight. We're starting to get the darker evenings back. Kind thoughts Bob

 Profile Send private message  
PostPosted: Thu Aug 17, 2017 3:23 pm 

Joined: Mon Jan 09, 2006 11:05 am
Posts: 5361
Location: Lancashire
If a star dims at the lunar limb it's usually a double. First, one component, then the other gets occulted. A single star snaps out immediately, unless its traversing behind lunar terrain before it disappears.
Some earlier observers thought that the dimming of stars at the lunar limb was possibly an indication of a lunar atmosphere.


 Profile Send private message  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC

Who is online

Users browsing this forum: No registered users and 14 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group