Sirius

Tiny points of light, with a magic all their own.
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Christopher K.
Posts: 4562
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Sirius

Post by Christopher K. » January 7th, 2014, 10:57 pm

I did something about ten minutes ago that I've never done...I went outside just to look at Sirius. It was hanging there a little east of south. Orion was a little west of south, so the central meridian was running between them. It was twinkling, but I couldn't discern any other color than its standard white. The night was very cold but the transparency is really good. Even with the first quarter Moon still up in the west and all kinds of light pollution around, the sky was covered with stars bright and dim.

Christopher K.
Posts: 4562
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Sirius

Post by Christopher K. » September 24th, 2014, 3:24 pm

Sirius has a companion, discovered in early 1862 by Alvan Clark. The two came closest (periastron) in 1944 and 1994 and, I assume, will do so again in 2044.

Below are the times during which Sirius reaches its culmination of forty-three degrees in the Baton Rouge sky...
23 October = 5:43am
27 October = 5:27am
31 October = 5:12am
Times above are Daylight. Times below are Standard.
4 November = 3:56am
8 November = 3:40am
12 November = 3:24am
16 November = 3:09am
20 November = 2:53am
24 November = 2:37am
28 November = 2:21am
2 December = 2:06am
6 December = 1:50am
10 December = 1:34am
14 December = 1:19am
18 December = 1:03am
22 December = 12:47am
26 December = 12:31am
30 December = 12:16am
3 January = 11:56am
7 January = 11:40pm
11 January = 11:25pm
15 January = 11:09pm
19 January = 10:53pm
23 January = 10:37pm
27 January = 10:22pm
31 January = 10:06pm
4 February = 9:50pm
8 February = 9:34pm
12 February = 9:19pm
16 February = 9:03pm
20 February = 8:47pm
24 February = 8:32pm
28 February = 8:16pm
4 March = 8:00pm
8 March = 7:44pm

More information:
Burnham's Celestial Handbook, pp. 386-400.

Christopher K.
Posts: 4562
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Sirius

Post by Christopher K. » October 8th, 2014, 2:56 am

Anxiously awaiting the lunar eclipse, I stepped outside the front doors of HRPO with a binocular to look at Sirius, which was about seventeen degrees up. It's blazing away; I purposefully put the binocular out of focus and the colorful twinkling intensified.

Chad Thibodeaux is here doing some sketching; Tom Northrop is setting up to take some lunar shots. I guess Ben and Jordan should be here shortly.

Christopher K.
Posts: 4562
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Sirius

Post by Christopher K. » August 7th, 2015, 6:14 pm

Though Sirius doesn't culminate until late October, sometime between tomorrow morning and the morning of the 14th it will probably experience its heliacal rising, which is the first time a star rises soon enough before sunrise to be detected with the unaided eyes. Which morning is that for the Baton Rouge area? I don't know! If I have the time and ability, I'll attempt a test.

Christopher K.
Posts: 4562
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Sirius

Post by Christopher K. » April 5th, 2016, 8:15 pm

This time of year yield's an intriguing fact. Sirius rises in the west in early spring as Arcturus is shining high in the east. At one instant, they are both the same altitude. When is that? Tonight for Baton Rouge, that's at ~9:44pm CDT.

Christopher K.
Posts: 4562
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Sirius

Post by Christopher K. » September 14th, 2016, 4:03 pm

A "sneak preview" of winter's sky occurs early tomorrow between 4:05am CDT and 5:20am CDT. Sirius (along with Orion and Gemini) will be occupying the east and southeast sky. Sadly, it will probably be too cloudy and humid to appreciate the view from Baton Rouge.

Christopher K.
Posts: 4562
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Sirius

Post by Christopher K. » May 4th, 2017, 5:24 pm

This may be the last week during which Sirius can still be seen after sunset. This can be tested night after night by using a clear western horizon and watching carefully. The last evening that Sirius can be seen is called its heliacal setting.

Christopher K.
Posts: 4562
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Sirius

Post by Christopher K. » December 22nd, 2017, 8:28 pm

Sirius rises tomorrow night at 7:17pm CST; at 8:37pm it will be fifteen degrees up. This is a perfect time to view it in a binocular and catch the incredible scintillation of the different colors.

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