Comments on: The North Star has spots! https://behindtheblack.com/behind-the-black/points-of-information/the-north-star-has-spots/ Sun, 25 Aug 2024 04:42:36 +0000 hourly 1 https://wordpress.org/?v=6.9.4 By: Blair Ivey https://behindtheblack.com/behind-the-black/points-of-information/the-north-star-has-spots/#comment-1514831 Sun, 25 Aug 2024 04:42:36 +0000 https://behindtheblack.com/?p=107680#comment-1514831 “But I am constant as the Northern Star,
Of whose true fixed and resting quality
There is no fellow in the firmament.
The skies are painted with unnumbered sparks;
They are all fire, and every one doth shine;
But there’s but one in all doth hold his place”

‘Julius Caesar’ Act III Scene I The Bard 1599

While I agree with McCoy’s assessment of Gen. Chang’s delivery, it was still core.

]]> By: Robert Zimmerman https://behindtheblack.com/behind-the-black/points-of-information/the-north-star-has-spots/#comment-1513449 Wed, 21 Aug 2024 23:57:23 +0000 https://behindtheblack.com/?p=107680#comment-1513449 In reply to John.

John wrote, “All this time it was a Cepheid variable and I had no idea.”

One of the first magazine articles I ever got published, in March 1995 for Astronomy, was specifically on Polaris and its variable star nature. I too was astonished then to discover it was a Cepheid that varied in brightness.

]]> By: John https://behindtheblack.com/behind-the-black/points-of-information/the-north-star-has-spots/#comment-1513448 Wed, 21 Aug 2024 23:50:33 +0000 https://behindtheblack.com/?p=107680#comment-1513448 Or maybe triple star system? from linked article, “It is the brightest member of a triple-star system and is a pulsating variable star. Polaris gets brighter and fainter periodically as the star’s diameter grows and shrinks over a four-day cycle.

All this time it was a Cepheid variable and I had no idea :(

]]> By: David Ross https://behindtheblack.com/behind-the-black/points-of-information/the-north-star-has-spots/#comment-1513243 Wed, 21 Aug 2024 16:56:57 +0000 https://behindtheblack.com/?p=107680#comment-1513243 What I didn’t know: Polaris A is a binary. Semimajor 6.2 AU = 29 times the stellar radius, Ab eccentricity = 0.635. Period ~29.4 years. This certainly helps gauge the mass-ratio.

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