HD 134060

HD 134060, also known by its Gould designation of 38 G. Circini, is a star in the southern constellation of Circinus. It is near the lower limit of stars visible to the naked eye, having an apparent visual magnitude of 6.29.^[2] The distance to HD 134060, as determined using an annual parallax shift measurement of 41.59 mas,^[1] is 78.4 light years. It is moving further away with a heliocentric radial velocity of 43.5 km/s, having come within 34.6 ly some 439,000 years ago.^[4]

HD 134060

Observation data Epoch J2000      Equinox J2000
Constellation	Circinus
Right ascension	15h 10m 44.74390s[1]
Declination	–61° 25′ 20.3469″[1]
Apparent magnitude (V)	6.29±0.01[2]
Characteristics
Spectral type	G0 V Fe+0.4[3] or G3 IV[2]
B−V color index	0.623±0.003[4]
Astrometry
Radial velocity (Rv)	43.50±0.74[4] km/s
Proper motion (μ)	RA: −185.615[1] mas/yr Dec.: −12.184[1] mas/yr
Parallax (π)	41.59 ± 0.23 mas[1]
Distance	78.4 ± 0.4 ly (24.0 ± 0.1 pc)
Absolute magnitude (MV)	4.37[4]
Details[2]
Mass	1.07±0.07 M☉
Radius	1.15±0.02 R☉
Luminosity	1.63[4] L☉
Surface gravity (log g)	4.35±0.04 cgs
Temperature	5,965±50 K
Metallicity [Fe/H]	+0.14±0.01 dex
Rotation	21.2±1.1 d[5]
Rotational velocity (v sin i)	3.21[6] km/s
Age	1.75[6] Gyr
Other designations
38 G. Circini, CD−60° 5490, HD 134060, HIP 74273, SAO 253043, LTT 6035[7]
Database references
SIMBAD	data

During the NStars project, Grey et al. (2006) found a stellar classification of G0 V Fe+0.4 for this star,^[3] matching a Sun-like G-type main-sequence star with an overabundance of iron in its outer atmosphere. However, an older classification of G3 IV^[2] is still used, which would suggest it is instead a more evolved subgiant star. HD 134060 has an estimated 1.07 times the mass of the Sun and 1.15 times the Sun's radius.^[2] It is radiating 1.63^[4] times the Sun's luminosity from its photosphere at an effective temperature of about 5,965 K.^[2]

The survey in 2015 have ruled out the existence of any additional stellar companions at projected distances from 22 to 163 astronomical units.^[8]

Planetary system

Based upon an 8-year survey using the HARPS spectrograph at La Silla Observatory, in 2011 the detection of a pair of planets orbiting this star were announced. The inner planet, HD 134060 b, is in a tight, eccentric orbit around the star with a period of just over three days. The second object, HD 134060 c, has a more leisurely period of around 3.2 years and a high orbital eccentricity.^[9]

The star was observed for a few hours by the Spitzer Space Telescope in the hopes of observing a transit by the inner planet, but none was detected.^[2] HD 134060 displays an infrared excess at a wavelength of 18μm, making it a warm debris disk candidate.^[10]

The HD 134060 planetary system^[11]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	0.0351±0.0021 MJ	0.0441±0.0010[6]	3.269555+0.000092 −0.000080[6]	0.480±0.034[6]	—	—
c	0.1507±0.071 MJ	2.2263±0.0507	1,160.9±27.046	0.75±0.19	—	—

References

1. Gaia Collaboration; Brown, A. G. A.; Vallenari, A.; Prusti, T.; De Bruijne, J. H. J.; Mignard, F.; Drimmel, R.; et al. (2016), "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties", Astronomy & Astrophysics, 595: A2, arXiv:1609.04172, Bibcode:2016A&A...595A...2G, doi:10.1051/0004-6361/201629512, S2CID 1828208.
2. Gillon, M.; et al. (May 2017), "The Spitzer search for the transits of HARPS low-mass planets. II. Null results for 19 planets", Astronomy & Astrophysics, 601: 23, arXiv:1701.01303, Bibcode:2017A&A...601A.117G, doi:10.1051/0004-6361/201629270, S2CID 86862862, A117.
3. Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
4. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
5. Suárez Mascareño, A.; Rebolo, R.; González Hernández, J. I.; Esposito, M. (2015), "Rotation periods of late-type dwarf stars from time series high-resolution spectroscopy of chromospheric indicators", Monthly Notices of the Royal Astronomical Society, 452 (3): 2745–2756, arXiv:1506.08039, Bibcode:2015MNRAS.452.2745S, doi:10.1093/mnras/stv1441
6. Delgado Mena, E.; et al. (April 2015), "Li abundances in F stars: planets, rotation, and Galactic evolution", Astronomy & Astrophysics, 576: 24, arXiv:1412.4618, Bibcode:2015A&A...576A..69D, doi:10.1051/0004-6361/201425433, S2CID 56051637, A69.
7. "HD 134060". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-12.
8. Mugrauer, M.; Ginski, C. (12 May 2015). "High-contrast imaging search for stellar and substellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 450 (3): 3127–3136. doi:10.1093/mnras/stv771. hdl:1887/49340. Retrieved 19 June 2020.
9. Mayor, M.; et al. (September 2011), "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets", arXiv:1109.2497 [astro-ph.EP]
10. Ishihara, Daisuke; et al. (May 2017), "Faint warm debris disks around nearby bright stars explored by AKARI and IRSF", Astronomy & Astrophysics, 601: 18, arXiv:1608.04480, Bibcode:2017A&A...601A..72I, doi:10.1051/0004-6361/201526215, S2CID 55234482, A72.
11. "The Extrasolar Planet Encyclopaedia — HD 134060 B". Archived from the original on 2014-02-02. Retrieved 2013-01-31.

External links

• "Planet HD 134060 b", Extrasolar Planets Encyclopaedia, retrieved 2018-07-13.
• "Planet HD 134060 c", Extrasolar Planets Encyclopaedia, retrieved 2018-07-13.