Results 21 to 30 of about 2,942 (136)

A Multiwavelength Classification and Study of Red Supergiant Candidates in NGC 6946

The Astrophysical Journal, 2023
We have combined resolved stellar photometry from Hubble Space Telescope (HST), Spitzer, and Gaia to identify red supergiant (RSG) candidates in NGC 6946, based on their colors, proper motions, visual morphologies, and spectral energy distributions.
Jared R. Johnson, Brad Koplitz, Benjamin F. Williams, Julianne J. Dalcanton, Andrew Dolphin, Léo Girardi   +5 more
doaj   +1 more source

Five New Sirius-like White Dwarf–Main-sequence Star Systems with MagAO-X

The Astronomical Journal
Most known white dwarfs in multiple systems with main-sequence stars have been discovered with M-type companions, because the white dwarf causes detectable UV excess and bluer colors than expected from a single M star.
Logan A. Pearce, Jared R. Males, Sebastiaan Y. Haffert, Laird M. Close, Joseph D. Long, Eden A. McEwen, Joshua Liberman, Maggie Y. Kautz, Jay K. Kueny, Alycia J. Weinberger, Jialin Li, Elena Tonucci, Katie Twitchell, Avalon L. McLeod, Warren B. Foster, Olivier Guyon, Alexander D. Hedglen, Kyle Van Gorkom, Jennifer Lumbres, Lauren Schatz, Victor Gasho, Katie M. Morzinski, Phil M. Hinz   +22 more
doaj   +1 more source

Search for DA White Dwarf Binary Candidates from LAMOST DR7

Universe, 2023
We obtained spectroscopy data for 761 Degenerate A (DA)white dwarfs (WDs) with multiple LAMOST observations. The radial velocity (RV) of each spectrum was calculated using the cross-correlation function method (CCF), and 60 DA WD binary candidates were ...
Hua-Hui Yan, Jing-Kun Zhao, Wei-Bin Shi, Jin-Cheng Guo, Liang Wang, Zhen-Xin Lei, Gang Zhao   +6 more
doaj   +1 more source

Don’t Believe the Hype(r): The Yellow Supergiants of Westerlund 1

The Astrophysical Journal, 2023
Yellow hypergiants (YHGs) are often presumed to represent a transitional post-red supergiant (RSG) phase for stars ∼30–40 M _⊙ . Here we present visual-wavelength echelle spectra of six YHG candidates in the Galactic cluster Westerlund 1, and we compare ...
Emma R. Beasor, Nathan Smith, Jennifer E. Andrews   +2 more
doaj   +1 more source

Orbits of Six Triple Systems

The Astronomical Journal
Joint analysis of position measurements and radial velocities of six triple stellar systems is conducted to determine their inner and/or outer orbits. Accumulation of such data is needed to study the architecture of stellar hierarchies and its relation ...
Andrei Tokovinin
doaj   +1 more source

Detecting New Visual Binaries in Gaia DR3 with Gaia and Two Micron All Sky Survey (2MASS) Photometry. II. Speckle Observations of 16 Low-separation Systems

The Astronomical Journal
Here we present speckle observations of 16 low-separation ( s < 30 au) high-probability candidate binaries from the catalog by Medan et al., where secondaries typically lack astrometric solutions in Gaia. From these speckle observations, we find a second
Ilija Medan, Sébastien Lépine, Zachary Hartman, Keivan G. Stassun   +3 more
doaj   +1 more source

Performance of the SOAR Speckle Instrument

The Astronomical Journal
The High Resolution Camera (HRCam) speckle imager at the 4.1 m Southern Astrophysical Research telescope is a highly productive instrument that has accumulated about 40K observations to date.
Andrei Tokovinin
doaj   +1 more source

Astronomical optical interferometry, II: Astrophysical results [PDF]

Serbian Astronomical Journal, 2011
Optical interferometry is entering a new age with several ground- based long-baseline observatories now making observations of unprecedented spatial resolution.
Jankov S.
doaj   +1 more source

Identification of Possible Stellar Companions via Speckle Interferometry in a Sample of Be Stars II

The Astronomical Journal
This study investigates the identification of possible stellar companions in a sample of Be stars using speckle interferometry. Be stars, which are rapidly rotating B-type stars exhibiting emission lines due to the presence of circumstellar disks, have ...
C. A. Guerrero, T. B. Souza, M. Borges Fernandes, A. D. Guajardo Jurado   +3 more
doaj   +1 more source

Orbits for sixteen binaries [PDF]

Serbian Astronomical Journal, 2006
In this paper orbits for 13 binaries are recalculated and presented. The reason is that recent observations show higher residuals than the corresponding ephemerides calculated by using the orbital elements given in the Sixth Catalog of Orbits of Visual ...
Cvetković Z., Novaković B.
doaj   +1 more source