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Unusual spectral types

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I've put together a list of prominent stars with various details so that I can get familiar with what I am actually looking at.

However, there are some really odd spectral types listed for some of them, for which I wasn't even able to find a definition online. Anyone know what these mean?

Am/dM1e (Castor B )

A0mA1 Va (Sirius A)

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On 26/07/2018 at 22:42, robin_astro said:

At least SIMBAD reports it as such


which was a surprise to me but I have not found any reference to it being so

I'm pretty sure the spectroscopic binary being referred to is in fact Sirius A and the Pup. The spectroscope was used in this case to determine that the velocity of A is variable, and is in close agreement with the result derived from visual observation.

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Perhaps, but there are separate entries in SIMBAD for Sirius (double or multiple star), Sirius A (spectroscopic binary), Sirius B (white dwarf).  The classification "spectroscopic binary" is normally used where a binary pair are not resolved or the companion is unseen (at least at the time of discovery) whereas the discovery of Sirius B predates astronomical spectroscopy and was first deduced from proper motion measurements and then found visually.

Maybe it refers to a long postulated third object which has now been discounted, though I believe evidence for that was also suspected anomalies in the proper motion  rather than spectroscopy


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I think it refers to the (now disproven) 1995 paper that there was a small (brown dwarf mass) companion - see: http://adsabs.harvard.edu/abs/1995A&A...299..621B

Can't imagine the presence of anything very large is very likely (or at least something that isn't very close to A) - anything else probably wouldn't be in a very stable orbit, esp considering that B was previously a much larger star before evolving off the main sequence - the current upper observational limits on orbiting bodies in the system are quite small.

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