Results 61 to 70 of about 5,486 (209)

BV CCD Photometry of M71: Distance and Age [PDF]

Journal of Astronomy and Space Sciences, 2004
We present BV CCD photometry of metal-rich globular cluster M71. Based on our color-magnitude diagram (CMD), we derive the distance to M71 using a sample of Hipparcos subdwarfs of similar metallicity. Our distance modulus is (m-M)V=13.46(± 0.17).
Hong-Suh Yim, Mun-Suk Chun, Yong-Ik Byun, Young-Jong Sohn   +3 more
doaj   +1 more source

Finding cool subdwarfs using a V-J reduced proper-motion diagram: Stellar parameters for 91 candidates

, 2003
We present the results of a search for cool subdwarfs for which our candidates were drawn from a V-J reduced proper-motion diagram constructed by Salim & Gould (2002).
Alonso A., David Yong, David L. Lambert, Edvardsson B., Goswami A., Grevesse N., Jorgensen U. G., Monet D. B. A., Schweitzer A.   +8 more
core   +2 more sources

Summary of Eighth Meeting on Hot Subdwarfs and Related Objects

Open Astronomy, 2017
Subjects discussed during the Eighth Meeting on Hot Subdwarfs and Related Objects are summarised. In particular, a succinct presentation is given of challenges to stellar evolution arising from recent observations.
Lynas-Gray Anthony Eugene
doaj   +1 more source

The hot subdwarfs revisited

The Astrophysical Journal, 1982
The properties and evolutionary status of the hot B and O subdwarfs are reinvestigated using recent homogeneous grids of hot, high-gravity model atmospheres and detailed convective envelope calculations appropriate to the hot subdwarf region of the H-R diagram discussed by Greenstein and Sargent.
F. Wesemael, D. E. Winget, W. Cabot, H. M. van Horn, G. Fontaine   +4 more
openaire   +1 more source

Detection of hot subdwarf binaries and He-poor hot subdwarf stars using machine learning methods and a large sample of Gaia XP spectra

Astronomy & Astrophysics
Context. Hot subdwarfs (hot sds) are compact evolved stars near the extreme horizontal branch, and they are key to understanding stellar evolution and the UV excess in galaxies.
Ambrosch M., Viscasillas Vázquez C., Solano E., Ulla A., Pérez-Couto X., Pérez-Fernández E., Medžiūnas A., Manteiga M., Dafonte C., Drazdauskas A., Magrini L., Mikolaitis Š., Šatas V.   +12 more
doaj   +1 more source

Are sdAs helium core stars?

Open Astronomy, 2017
Evolved stars with a helium core can be formed by non-conservative mass exchange interaction with a companion or by strong mass loss. Their masses are smaller than 0.5 M⊙. In the database of the Sloan Digital Sky Survey (SDSS), there are several thousand
Pelisoli Ingrid, Kepler S. O., Koester Detlev   +2 more
doaj   +1 more source

A search for lithium in metal-poor L dwarfs

, 2015
The aim of the project is to search for lithium in absorption at 6707.8 Angstroms to constrain the nature and the mass of the brightest low-metallicity L-type dwarfs (refered to as L subdwarfs) identified in large-scale surveys.
Burgasser, A. J., Lodieu, N., Pavlenko, Y., Rebolo, R.   +3 more
core   +1 more source

COOL SUBDWARF INVESTIGATIONS. II. MULTIPLICITY [PDF]

The Astronomical Journal, 2009
accepted by ...
Jao, Wei-Chun, Mason, Brian D., Hartkopf, William I, Henry, Todd J., Ramos, Stephanie N.   +4 more
openaire   +2 more sources

An additional pulsating mode (7.35 mHz) and pulsations timing variations of PG 1613+426

Open Astronomy, 2017
We present the detection of an additional pulsation mode (7.35 mHz) of a subdwarf B star, PG 1613+426, and periodic Observed minus Calculated (O-C) variations for two existing pulsations. PG 1613+426 is near the hot end of the sdB instability strip.
Otani Tomomi, Oswalt Terry D., Majewski Patrice, Jordan Riley, Amaral Marc, Moss Adam   +5 more
doaj   +1 more source

The Solar Neighborhood XXVII: Discovery of New Proper Motion Stars with mu > 0.18 "/yr in the Southern Sky with 16.5 > R_59F > 18.0

, 2011
Here we present 1584 new southern proper motion systems with mu > 0.18 "/yr and 16.5 > R_59F > 18.0. This search complements the six previous SuperCOSMOS-RECONS (SCR) proper motion searches of the southern sky for stars within the same proper motion ...
Bakos, Boyd, Burgasser, Finch, Finch, Giclas, Giclas, Hambly, Henry, Henry, Holberg, Jao, Jao, Jao, John P. Subasavage, Luyten, Luyten, Luyten, Lépine, Lépine, Mark R. Boyd, Nigel C. Hambly, Riedel, Subasavage, Subasavage, Subasavage, Todd J. Henry, Wei-Chun Jao   +27 more
core   +1 more source