M 40 not a physical double star

[wvreeven]

Dear all,

Today I noticed this paper on arXiv

https://arxiv.org/abs/1612.00834

The authors have used the parallaxes in the Tycho/Gaia data release of September 2016 to show that the two components of M 40 don't form a physical double star. The parallaxes are too different.


Clear skies,

Wouter

[Don Pensack]

Interesting to read (it's been in the on-line news recently). I looked at this back in 1963 and haven't looked again since. Have you?
Now if Beta Cygni were proven to be an optical rather than true double (or triple, as the case may be, since the brighter one is a spectroscopic double),
that would be eye-popping news.

[wvreeven]

Beta 1 Cygni (the brighter component of Albireo) is not in the Tycho/Gaia data release since it is too bright. Beta 2 Cygni is in the data release with a parallax of 7.37 (+/- 0.98) which is in line with previous measurements. As soon as the next Gaia data release is done we will know more because that should contain both components.