The Big Dipper

Tiny points of light, with a magic all their own.
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Christopher K.
Posts: 5474
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

The Big Dipper

Post by Christopher K. »

Probably the most famous asterism in the night sky is "upside down" tonight. If you go out, say, anytime from 9:15pm to 10:45pm you can see it stretching from the north to the northeast. Remember, the handle "arcs to Arcturus".

Christopher K.
Posts: 5474
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: The Big Dipper

Post by Christopher K. »

I kicked off a nice night of viewing this past Monday with this old favorite. The seeing was actually nice, but the dipper was immersed in the northern light dome, almost as though someone stuck it in a hazy grey sink of dishwater. I saw the three handle stars and (probably) Dubhe.

Christopher K.
Posts: 5474
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: The Big Dipper

Post by Christopher K. »

Tuesday night at ~8:45pm I attempted to spot Arcturus and the Big Dipper. There were some clouds to the southwest but they spared Arcturus and I saw it with no problem. The Big Dipper was another story; it was so low I only saw Alkaid and Mizar. Any who want to look too need to try tonight or tomorrow night to see roughly the same orientation.

Christopher K.
Posts: 5474
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: The Big Dipper

Post by Christopher K. »

Early tonight is not the time to look for the Big Dipper because you won't find it. Anyone wanting to see it standing on its handle in the northeast will have to wait until at least 3am CST tomorrow morning.

Christopher K.
Posts: 5474
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: The Big Dipper

Post by Christopher K. »

I trained a Bushnell 10x at Alkaid, Alioth and Dubhe a little over a half-hour ago. When I looked at Alioth I saw nearby 78 Ursae Majoris (F-class, mag 4.9). This may be the first I've noticed of Dubhe's orange tint.

Christopher K.
Posts: 5474
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: The Big Dipper

Post by Christopher K. »

Tonight at 10pm CDT go outside, face north and look about two-thirds of the way up. The Big Dipper is emptying its contents onto the landscape below! Of course that means Cassiopeia (which is always on the opposite side of the North Star) is buried below the horizon.

In fact this an EXCELLENT night for skygazing. Here's the NOAA forecast for 10pm to 12am...
precipitation potential, 1%
sky cover, 4%
relative humidity, 77%
temperature, 24˚C
surface wind, S 8 km/h

Danko's Clear Dark Sky states that during this time the transparency rating will be "above average" (4 out of 5) and the seeing rating will be "average" (3 out of 5). View with caution, though; there is an Air Quality Alert until midnight.

Christopher K.
Posts: 5474
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: The Big Dipper

Post by Christopher K. »

The Mizar-Alcor group will be a planned telescopic target from 9:45pm to 10:15pm during HRPO's next viewing session on Saturday 11 May. Although it is mid-May and Daylight Time is still in effect, twilight will have ended.

Christopher K.
Posts: 5474
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: The Big Dipper

Post by Christopher K. »

The Big Dipper is at its highest tonight due north at about 11:45pm CDT. The seeing will leave something to be desired, but the transparency should cooperate fully.

The Dipper will be upside down. If you follow the curve made by its crooked handle, you will arc to orange magnitude 0 Arcturus then speed on to blue magnitude 1 Spica. (Both of these stars can be seen in the southeast.)

Christopher K.
Posts: 5474
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Using the The Big Dipper to Find Other Night Sky Features

Post by Christopher K. »

Who knows the trick of using the Big Dipper to find some of the most notable and beautiful features in the spring night sky? This asterism is a key to unlock a large portion of the Baton Rouge celestial sphere--from Arcturus and Spica to Polaris, from golden Capella to Deneb (the top of the Northern Cross)!

The Big Dipper should be visible over the next few nights in the north-northeast beginning at around 8:45pm CDT.

Scott Levine's 29 April Big Dipper article contains detailed instructions...
https://skyandtelescope.org/observing/b ... ky-sights/

This interactive map from Jim Kaler labels the prominent stars of the Big Dipper...
http://stars.astro.illinois.edu/sow/uma-p.html

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