Monday, May 15, 2023

enjoyed Aitken's first sighting of Sirius B

I read the September 1942 edition (volume 1 number 11) of Sky & Telescope. From the Seven Decade Collection.

A good source of reading material while I'm... resting for a while. I had forgotten about this!


Really enjoyed the fascinating intimate account of Robert G Aitken's first personal measurement of Sirius B as a young, unknown astronomer working at Lick Observatory on Mt Hamilton. In somewhat of an accident!

On 23 October 1896, with the 12-inch telescope, Aitken made the first direct measurement of Sirius B in some years. His work was verified the following night by Professor J M Schaeberle.

Aitken's article then delved into the earlier historical notes on the brightest star in the sky, such as Halley discovering its proper motion and Bessel proposing the influence of a massive but unseen companion. In fact, Bessel computed a 50 year period for the nearby dark star.

It was Alvan G Clark with an 18½ telescope at the Dearborn Observatory who visually saw Sirius B in 1862. This triggered a flurry of measurements by double star observers as the tiny companion arced ever closer to the bright host. They watched for 30 years but they could not compute a good orbit. 

Burnham was the last to see it in 1892. 

As Aitken re-aquired it, they substantiated Bessel's predictions.


Later in the issue, William H Barton Jr, in his Autumn Skies piece, encouraged observers to view Epsilon Lyrae. He cautioned that "a person with keen eyesight can separate the stars, but the average person cannot." In a telescope, it will be apparent why some call it the "double double."

Barton remarks that colourful Albireo is beautiful in the telescope.

He urges people to run what you brung. "Many people who possess spyglasses or good field glasses or binoculars fail to appreciate how much hidden beauty they will reveal." 

Oh, I like that.

Barton does a bit of deep dive into intriguing Mizar.

He closes on the importance on the studying and naming of stars, at the time, necessary in the grim war-time defense efforts.

A double star, delta, is noted being near to Jupiter, at 10 minutes on September 1. This provided by Jessa A Fitzpatrick on his Observer's Page column.

And finally, Leland S Copeland suggests a number of double star targets in his The Starry Heavens in September article.

Doubles galore!

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