J/AJ/156/64 RV measurements for 6 K giants in the SENS program (Jeong+, 2018)
A search for exoplanets around Northern Circumpolar Stars.
IV. Six planet candidates to the K giants, HD 44385, HD 97619, HD 106574,
HD 118904, HD 164428, and HD 202432.
Jeong G., Han I., Park M.-G., Hatzes A.P., Bang T.-Y., Gu S., Bai J.,
Lee B.-C.
<Astron. J., 156, 64 (2018)>
=2018AJ....156...64J 2018AJ....156...64J (SIMBAD/NED BibCode)
ADC_Keywords: Stars, K-type ; Stars, giant ; Radial velocities ; Exoplanets
Keywords: planetary systems - stars: late-type - techniques: radial velocities
Abstract:
We report the discovery of long-period radial velocity (RV) variations
in six intermediate-mass K-giant stars using precise RV measurements.
These discoveries are part of the Search for Exoplanets around Northern
Circumpolar Stars (SENS) survey being conducted at the Bohyunsan Optical
Astronomy Observatory. The nature of the RV variations was investigated
by looking for photometric and line shape variations. We can find no
variability with the RV period in these quantities and conclude that
RV variations are most likely due to unseen sub-stellar companions.
Orbital solutions for the six stars yield orbital periods in the range
418-1065 days and minimum masses in the range 1.9-8.5 MJ. These
properties are typical on planets around intermediate-mass stars. Our
SENS survey so far has about an 8% confirmed planet occurrence rate,
and it will provide better statistics on planets around giant stars when
the survey is completed.
Description:
In 2010, we began a new program, the Search for Exoplanet around Northern
circumpolar Stars (SENS; Lee et al. 2015A&A...584A..79L 2015A&A...584A..79L). The main goal
of SENS is to observe stars that are accessible year-round in order to
have better sampling for our targets and thus increase the planet detection
efficiency. The stars of SENS were selected from the HIPPARCOS catalog
with visual magnitudes of 5.0<mv<7.0 and color indices of 0.6<B-V<1.6.
Observations were made with the high-resolution fiber-fed Bohyunsan
Observatory Echelle Spectrograph (BOES; Kim et al. 2007PASP..119.1052K 2007PASP..119.1052K)
of the 1.8 m telescope at BOAO. An iodine (I2) absorption cell is
equipped in BOES for precise RV measurements. BOES has three fibers with
80, 200, and 300 µm of diameter, which give resolutions of R=90000,
45000, and 27000, respectively. For our program, we used the 200 µm
fiber. A typical exposure time of 20 minutes yielded a signal-to-noise
ratio (S/N) of about 150. Since the start of the program in 2010 January,
we have collected 30 spectra each for HD 44385, HD 97619, HD 106574,
HD 118904, HD 164428, and HD 202432. In order to check the instrumental
stability, we have monitored an τ Ceti by standard since 2003. The
long-term RV accuracy of BOES is ∼7.6 m/s.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 33 6 List of stars
table3.dat 33 198 RV measurements
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See also:
J/A+A/430/165 : Radial velocities for 6691 K and M giants (Famaey+, 2005)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Stellar identifier (HD NNNNNN)
11- 12 I2 h RAh Simbad Hour of Right Ascension (J2000)
14- 15 I2 min RAm Simbad Minute of Right Ascension (J2000)
17- 21 F5.2 s RAs Simbad Second of Right Ascension (J2000)
23 A1 --- DE- Simbad Sign of the Declination (J2000)
24- 25 I2 deg DEd Simbad Degree of Declination (J2000)
27- 28 I2 arcmin DEm Simbad Arcminute of Declination (J2000)
30- 33 F4.1 arcsec DEs Simbad Arcsecond of Declination (J2000)
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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- 9 A9 --- Star Stellar identifier (HD NNNNNN)
11- 21 F11.6 d JD [5132.94597/8151.089358] Julian Date (JD-2450000)
23- 28 F6.1 m/s RV [-183.2/182.9] Radial velocity
30- 33 F4.1 m/s e_RV [8.6/70.5] The 1σ uncertainty in RV
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 04-Feb-2019