J/AJ/157/136 RVs of RGs with suspected massive companions (Makarov+, 2019)
Observations of red giants with suspected massive companions.
Makarov V.V., Tokovinin A.
<Astron. J., 157, 136 (2019)>
=2019AJ....157..136M 2019AJ....157..136M (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Stars, giant ; Radial velocities
Keywords: binaries: spectroscopic
Abstract:
Motivated by the existence of binary systems where a stellar-mass black
hole is bound to a normal star, we selected four red giants with large
radial velocity (RV) variation from the survey of Space Interferometry
Mission (SIM) grid stars and monitored their RVs for several months.
None turned out to contain a massive companion above 2.5 solar masses.
The red giant TYC 9299-1080-1 with a large RV and a large proper motion
is a single-lined spectroscopic binary with a period of 81 days. It is
an extreme halo object moving at 350 km/s almost directly toward the
Galactic center. HD 206092 is a double-lined binary with a short period
of 4.37 days. It belongs to the rare class of active RS CVn-type binaries
with evolved primary components, apparently undergoing mass transfer.
The X-ray luminosity of HD 206092 is about twice as high as the most
luminous coronal X-ray emitters observed by ROSAT, including II Peg and
the prototype star RS CVn. HD 318347 has a variable double-peaked
emission-line spectrum (not a giant), while HD 324668 has a constant RV.
Despite the overall good quality of the SIM survey data confirmed by a
comparison with Gaia Data Release 2 (DR2, Cat. I/345) mean RVs, the few
large RV variations are explained, mostly, by erroneous data. We discuss
the significance of the non-detection of massive companions in the SIM
grid sample and the associated work.
Description:
The observations reported here were conducted at the 1.5 m telescope
located at Cerro Tololo (Chile) and operated by the SMARTS consortium.
Ten hours of observing time were allocated through the National Optical
Astronomy Observatory (NOAO). Spectra were taken by the telescope
operator in the service mode. The optical echelle spectrometer CHIRON
(Tokovinin et al. 2013PASP..125.1336T 2013PASP..125.1336T) was used in the fiber mode with
a spectral resolution of 30000. On each visit, a single five-minute
exposure of the star was taken, accompanied by the spectrum of the
comparison lamp for wavelength calibration. The RVs are derived from the
reduced spectra by cross-correlation with a binary mask based on the solar
spectrum, similarly to the CORALIE RVs. We used 39 echelle orders in
the spectral range from 4500 to 6500 Å, which is relatively less
contaminated by telluric lines. More details are provided by Tokovinin
(2016, J/AJ/152/11).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 78 4 List of candidates
table3.dat 36 43 Radial velocities
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See also:
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/152/11 : Orbits of four triple stars (Tokovinin, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- TYC Tycho identifier (NNNN-NNNN-N)
13- 18 I6 --- HD [206092/324668]? HD number
20- 34 A15 --- Name Object identifier in Table 3
36- 40 F5.2 mag Vmag [9.71/10.02] Visual magnitude
42- 46 A5 --- SpType Spectral type as given in Simbad
48- 52 F5.3 mas Plx [0.729/2.592] Parallaxe (1)
54- 58 F5.3 mas e_Plx [0.025/0.052] Uncertainty in Plx (1)
60- 72 A13 --- Note Note
74- 78 F5.2 d Per [4.37/81]? Orbital period
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Note (1): Parallaxes and errors are from the Gaia DR2 (Gaia Collaboration et al.
2018, Cat. I/345).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Object identifier
17- 26 F10.4 d JD [58260.847/58406.486] Julian Date (JD-2400000)
28- 34 F7.3 km/s RV [-85.55/335.944] Radial velocity
36 A1 --- m_Name [ab] Component label
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 14-Jun-2019