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A review of 70 years with astrometry: From meridian circles to Gaia and beyond
Høg, Erik
In 1953 I heard of an experiment in 1925 by Bengt Strömgren where he observed transit times with the meridian circle at the Copenhagen University Observatory measuring the current in a photocell behind slits when a star was crossing. In 1954 just 22 years old I was given the task as a student to make first test observations with a new meridian cir…
The Pleiades apex and its kinematical structure
Yadav, R. K. S.; Vereshchagin, S. V.; Chupina, N. V. +4 more
A study of cluster characteristics and internal kinematical structure of the middle-aged Pleiades open star cluster is presented. The individual star apexes and various cluster kinematical parameters including the velocity ellipsoid parameters are determined using both Hipparcos and Gaia data. Modern astrometric parameters were taken from the Gaia…
A simultaneous spectroscopic and photometric study of two eclipsing binaries: V566 Oph and V972 Her
Yılmaz, M.; Selam, S. O.; Esmer, E. M. +4 more
In this study, we have performed simultaneous solutions of light and radial velocity curves of two eclipsing binary systems, V566 Oph and V972 Her. We observed both systems spectroscopically with a very recently installed spectrograph on the 40 cm telescope, T40, located in Ankara University Kreiken Observatory (AUKR), for the first time. We made …
The distance to the Galactic center determined by G, K, and M stars
Branham, Richard L.
The distance from the Sun to the center of the Galaxy
Metallicity calibration and photometric parallax estimation: II. SDSS photometry
Bilir, S.; Ak, T.; Karaali, S. +4 more
We used the updated [Fe/H] abundances of 168 F-G type dwarfs and calibrated them to a third order polynomial in terms of reduced ultraviolet excess,
The distance to the Galactic center determined by A–F stars
Branham, Richard L.
The distance from the sun to the center of the Galaxy
The distance to the Galactic center determined by OB stars
Branham, Richard L.
The OB stars are concentrated near the Galactic plane and should permit a determination of the distance to the Galactic center. van Leeuwen's new reduction of the Hipparcos catalog provides, after 824 Gould belt stars have been excluded, 6288 OB stars out to 1 kpc and Westin's compilation an additional 112 stars between 1 kpc and 3 kpc. The reduct…
Absolute magnitude calibration for red clump stars
Bilir, S.; Karaali, S.; Yaz Gökçe, E.
We combined the (Ks, J‑Ks) data in Laney et al. (Mon. Not. R. Astron. Soc. 419:1637, 2012) with the V apparent magnitudes and trigonometric parallaxes taken from the Hipparcos catalogue and used them to fit the
Asymptotic Giant Branch variables in the Galaxy and the Local Group
Whitelock, Patricia A.
AGB variables, particularly the large amplitude Mira type, are a vital step on the distance scale ladder. They will prove particularly important in the era of space telescopes and extremely large ground-based telescopes with adaptive optics, which will be optimized for infrared observing. Our current understanding of the distances to these stars i…
Building the cosmic distance scale: from Hipparcos to Gaia
Turon, Catherine; Luri, Xavier; Masana, Eduard
Hipparcos, the first ever experiment of global astrometry, was launched by ESA (European Space Agency) in 1989 and its results published in 1997 (Perryman et al. in Astron. Astrophys. 323:L49, 1997; Perryman & ESA (eds.) in The Hipparcos and Tycho catalogues, ESA SP-1200, 1997). A new reduction was later performed using an improved satellite a…