Recent results have suggested that there is tension between the Gaia DR1 TGAS distances and the distances obtained using luminosities determined by eclipsing binaries or asteroseismology on red giant stars. We use the Ks-band luminosities of red clump stars, identified and characterized by asteroseismology, to make independent distance estimates. Our results suggest that Gaia TGAS distances contain a systematic error that decreases with increasing distance. We propose a correction to mitigate this offset as a function of parallax that is valid for the Kepler field and values of parallax that are less than ∼1.6 mas. For parallaxes greater than this, we find agreement with previously published values. We note that the TGAS distances to the red clump stars of the open cluster M67 show a high level of disagreement that is difficult to correct for.
Using red clump stars to correct the Gaia DR1 parallaxes / Davies G.R.; Lund M.N.; Miglio A.; Elsworth Y.; Kuszlewicz J.S.; North T.S.H.; Rendle B.; Chaplin W.J.; Rodrigues T.S.; Campante T.L.; Girardi L.; Hale S.J.; Hall O.; Jones C.D.; Kawaler S.D.; Roxburgh I.; Schofield M.. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - ELETTRONICO. - 598:(2017), pp. L4.1-L4.5. [10.1051/0004-6361/201630066]
Using red clump stars to correct the Gaia DR1 parallaxes
Miglio A.;
2017
Abstract
Recent results have suggested that there is tension between the Gaia DR1 TGAS distances and the distances obtained using luminosities determined by eclipsing binaries or asteroseismology on red giant stars. We use the Ks-band luminosities of red clump stars, identified and characterized by asteroseismology, to make independent distance estimates. Our results suggest that Gaia TGAS distances contain a systematic error that decreases with increasing distance. We propose a correction to mitigate this offset as a function of parallax that is valid for the Kepler field and values of parallax that are less than ∼1.6 mas. For parallaxes greater than this, we find agreement with previously published values. We note that the TGAS distances to the red clump stars of the open cluster M67 show a high level of disagreement that is difficult to correct for.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
