The mass of Albireo Aa and the nature of Albireo AB: new aspects from Gaia DR2

<i>Aims.<i/> We aim to clarify the nature of Albireo AB and specifically to decipher whether it is an optical or physical pair. We also try to determine the mass of Albireo Aa.<i>Methods.<i/> We scrutinize and compare the available absolute astrometric data (from HIPPARCOS an...

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Hauptverfasser: Bastian, Ulrich (VerfasserIn) , Anton, Rainer (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: 26 November 2018
In: Astronomy and astrophysics
Year: 2018, Jahrgang: 620
ISSN:1432-0746
DOI:10.1051/0004-6361/201834351
Online-Zugang:Verlag, Volltext: http://dx.doi.org/10.1051/0004-6361/201834351
Verlag, Volltext: https://www.aanda.org/articles/aa/pdf/2018/12/aa34351-18.pdf
Volltext
Verfasserangaben:U. Bastian, R. Anton
Beschreibung
Zusammenfassung:<i>Aims.<i/> We aim to clarify the nature of Albireo AB and specifically to decipher whether it is an optical or physical pair. We also try to determine the mass of Albireo Aa.<i>Methods.<i/> We scrutinize and compare the available absolute astrometric data (from HIPPARCOS and <i>Gaia<i/> DR2) of Albireo A and B, and we investigate the relative orbit of the pair Albireo Aa,Ac using orbit solutions based on ground-based interferometric measurements.<i>Results.<i/> The mass of Albireo Aa (K3 II) is surprisingly small; only an upper limit of about 0.7 <i>M<i/><sub>⊙<sub/> could be derived. The systemic proper motion of Aa,Ac differs from that of component B by about 10 mas year<sup>−1<sup/> with an uncertainty of less than 2 mas year<sup>−1<sup/>. Albireo AB is therefore most probably an optical double.<i>Conclusions.<i/> Specific astrometric and spectroscopic follow-up observations clarifying the surprising mass estimate for Albireo Aa are recommended.
Beschreibung:Gesehen am 13.02.2019
Beschreibung:Online Resource
ISSN:1432-0746
DOI:10.1051/0004-6361/201834351