Long-period radial velocity variations in three K giants

1993 ◽  
Vol 413 ◽  
pp. 339 ◽  
Author(s):  
Artie P. Hatzes ◽  
William D. Cochran
Keyword(s):  
Radial Velocity ◽  
Long Period ◽  
Velocity Variations ◽  
K Giants

scholarly journals Low-amplitude and long-period radial velocity variations in giants HD 3574, 63 Cygni, and HD 216946

2014 ◽  
Vol 566 ◽  
pp. A124
Author(s):  
B.-C. Lee ◽  
I. Han ◽  
M.-G. Park ◽  
A. P. Hatzes ◽  
K.-M. Kim
Keyword(s):  
Radial Velocity ◽  
Long Period ◽  
Velocity Variations ◽  
Low Amplitude

scholarly journals Detection of planet candidates around K giants. HD 40956, HD 111591, and HD 113996

2018 ◽  
Vol 610 ◽  
pp. A3 ◽  
Author(s):  
G. Jeong ◽  
B.-C. Lee ◽  
I. Han ◽  
M. Omiya ◽  
H. Izumiura ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Astronomy Observatory ◽  
Giant Stars ◽  
Long Period ◽  
Substellar Companions ◽  
Optical Astronomy ◽  
K Giants

Aims. The purpose of this paper is to detect and investigate the nature of long-term radial velocity (RV) variations of K-type giants and to confirm planetary companions around the stars. Methods. We have conducted two planet search programs by precise RV measurement using the 1.8 m telescope at Bohyunsan Optical Astronomy Observatory (BOAO) and the 1.88 m telescope at Okayama Astrophysical Observatory (OAO). The BOAO program searches for planets around 55 early K giants. The OAO program is looking for 190 G–K type giants. Results. In this paper, we report the detection of long-period RV variations of three K giant stars, HD 40956, HD 111591, and HD 113996. We investigated the cause of the observed RV variations and conclude the substellar companions are most likely the cause of the RV variations. The orbital analyses yield P = 578.6 ± 3.3 d, m sin i = 2.7 ± 0.6 MJ, a = 1.4 ± 0.1 AU for HD 40956; P = 1056.4 ± 14.3 d, m sin i = 4.4 ± 0.4 MJ, a = 2.5 ± 0.1 AU for HD 111591; P = 610.2 ± 3.8 d, m sin i = 6.3 ± 1.0 MJ, a = 1.6 ± 0.1 AU for HD 113996.

scholarly journals Two new double-lined spectroscopic binary white dwarfs

2020 ◽  
Vol 493 (2) ◽  
pp. 2805-2816 ◽  
Author(s):  
Mukremin Kilic ◽  
A Bédard ◽  
P Bergeron ◽  
Alekzander Kosakowski
Keyword(s):  
Radial Velocity ◽  
White Dwarf ◽  
White Dwarfs ◽  
Binary Systems ◽  
Mass Ratio ◽  
Orbital Parameters ◽  
Long Period ◽  
Spectroscopic Binary ◽  
Velocity Variations ◽  
Period System

ABSTRACT We present radial velocity observations of four binary white dwarf candidates identified through their overluminosity. We identify two new double-lined spectroscopic binary systems, WD 0311–649 and WD 1606+422, and constrain their orbital parameters. WD 0311–649 is a 17.7 h period system with a mass ratio of 1.44 ± 0.06 and WD 1606+422 is a 20.1 h period system with a mass ratio of 1.33 ± 0.03. An additional object, WD 1447–190, is a 43 h period single-lined white dwarf binary, whereas WD 1418–088 does not show any significant velocity variations over time-scales ranging from minutes to decades. We present an overview of the 14 overluminous white dwarfs that were identified by Bédard et al., and find the fraction of double- and single-lined systems to be both 31 per cent. However, an additional 31 per cent of these overluminous white dwarfs do not show any significant radial velocity variations. We demonstrate that these must be in long-period binaries that may be resolved by Gaia astrometry. We also discuss the overabundance of single low-mass white dwarfs identified in the SPY survey, and suggest that some of those systems are also likely long-period binary systems of more massive white dwarfs.

Bright Giants with Small Amplitude Long Period Velocity Variability

1984 ◽  
Vol 88 ◽  
pp. 289-297
Author(s):  
Willet I. Beavers
Keyword(s):  
Radial Velocity ◽  
Small Amplitude ◽  
Variable Velocity ◽  
Complete Cycle ◽  
Giant Stars ◽  
Long Period ◽  
Velocity Variations

AbstractObservations during the first eight years of operation of the Fick Observatory photoelectric radial velocity spectrometer have led to the development of a list of approximately seventy bright late giant stars with suspected small amplitude long period velocity variations. Some of these stars have been identified as variable velocity objects by other observers, and a few of them have previous low quality orbit determinations or estimations. Preliminary SB1 orbits are reported for eight of the list members which have been observed through at least one complete cycle. Estimates of the period (P) and velocity semiamplitude (K) are made for other confirmed variables. Generally, the sample contains long P (2 to 8 years), small K (4 to 14 km/sec), late giant systems.

scholarly journals Velocity Observations of Multiple Mode AGB Variable Stars

2002 ◽  
Vol 185 ◽  
pp. 560-561
Author(s):  
T. Lebzelter ◽  
K.H. Hinkle ◽  
R.R. Joyce ◽  
F.C. Fekel
Keyword(s):  
Radial Velocity ◽  
Orbital Motion ◽  
Variable Stars ◽  
Spectroscopic Observations ◽  
Long Period ◽  
Multiple Mode ◽  
Infrared Spectroscopic ◽  
Velocity Variations ◽  
Velocity Changes ◽  
Light Variability

AbstractNumerous infrared Spectroscopic observations were obtained of eight AGB field M giants that have multiple periods of light variability. For six of the eight giants we found radial-velocity periods that confirm the long-period light variability. Although we consider the possibility that the velocity variations result from orbital motion, we conclude that the long-period velocity changes in most, if not all of our sample stars, likely result from pulsation rather than duplicity.

Search for Long-Period Radial Velocity Variations in Some Be Stars

Be Stars ◽  
1982 ◽  
pp. 155-159
Author(s):  
L. Pastori ◽  
E. Antonello ◽  
M. Fracassini ◽  
L. E. Pasinetti
Keyword(s):  
Radial Velocity ◽  
Be Stars ◽  
Long Period ◽  
Velocity Variations

Long-period radial-velocity variations of Arcturus

1989 ◽  
Vol 101 ◽  
pp. 147 ◽  
Author(s):  
Alan W. Irwin ◽  
Bruce Campbell ◽  
Christopher L. Morbey ◽  
G. A. H. Walker ◽  
S. Yang
Keyword(s):  
Radial Velocity ◽  
Long Period ◽  
Velocity Variations

scholarly journals Long-lived, long-period radial velocity variations in Aldebaran: A planetary companion and stellar activity

2015 ◽  
Vol 580 ◽  
pp. A31 ◽  
Author(s):  
A. P. Hatzes ◽  
W. D. Cochran ◽  
M. Endl ◽  
E. W. Guenther ◽  
P. MacQueen ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Stellar Activity ◽  
Long Period ◽  
Velocity Variations

scholarly journals Long period variables in the globular cluster 47 Tuc: Radial velocity variations

2005 ◽  
Vol 432 (1) ◽  
pp. 207-217 ◽  
Author(s):  
T. Lebzelter ◽  
P. R. Wood ◽  
K. H. Hinkle ◽  
R. R. Joyce ◽  
F. C. Fekel
Keyword(s):  
Radial Velocity ◽  
Globular Cluster ◽  
Long Period ◽  
Long Period Variables ◽  
Velocity Variations
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