J/A+A/529/A134 Velocity curve of α Arietis (Lee+, 2011)
A likely exoplanet orbiting the oscillating K-giant alpha Arietis.
Lee B.-C., Mkrtichian D.E., Han I., Kim K.-M., Park M.-G.
<Astron. Astrophys. 529, A134 (2011)>
=2011A&A...529A.134L 2011A&A...529A.134L
ADC_Keywords: Stars, double and multiple ; Stars, giant ; Planets ;
Radial velocities
Keywords: planetary systems - stars: individual: alpha Arietis -
technique: radial velocity
Abstract:
To search for extra-solar planets around intermediate mass stars, we
are conducting a precise RV survey around K-giants.
We present high-accuracy RV measurements of alpha Ari from November
2003 to February 2010. This star belongs to our sample of 55 K-giants
studied for extra-solar planet and pulsation searches using the
fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) attached
to the 1.8-m telescope at Bohyunsan Optical Astronomy Observatory
(BOAO) in Korea.
We find a planetary companion with a long-period and low-amplitude
radial velocity (RV) variations in oscillating K2 III star alpha Ari
(HD 12929). We do not find the correlation between RV variations and
chromospheric activity indicators (CaII H & K region, Hα line).
The bisector analysis also shows that bisector velocity span (BVS)
does not show any obvious correlation with RV variation but has
periodic component that may be attributed to the rotation of the star.
If the RV variation is indeed caused by a planetary companion, an
orbital solution with a period of P=381-days, a semi-amplitude of
K=41m/s, and an eccentricity of e=0.25 fits the data best. Assuming a
possible stellar mass of Mstar=1.5M☉, we estimate the minimum
mass for the planetary companion of m2sini=1.8M♃ with an
orbital semi-major axis of 1.2AU.
Our finding of a likely exoplanet in alpha Ari gives a support to
search for extra-solar planets around giant stars with multi-periodic
oscillations.
Description:
The RV measurements obtained from November 2003 until February 2010.
Objects:
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RA (2000) DE Designation(s)
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02 07 10.4 +23 27 45 alpha Ari = HD 12929
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 25 678 Radial velocity of alpha Ari
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 --- HJD Heliocentric Julian date of the observation
16- 20 F5.1 m/s RV Radial velocity
22- 25 F4.1 m/s e_RV Standard error of RV
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Acknowledgements:
Byeng-Cheol Lee, bclee(at)kasi.re.kr
(End) Byeong-Cheol Lee [KASI, Korea], Patricia Vannier [CDS] 11-Mar-2011