HD 142250 (HR 5910, HIP 77900) is a star in the constellation Scorpius. It has a visual apparent magnitude of 6.1, being visible to the naked eye only in excellent seeing conditions. From parallax measurements, it is located 486 light-years (149 parsecs) away from Earth. This distance, together with the star's proper motion, indicate that HIP 77900 is a member of the Upper Scorpius subgroup of the Scorpius–Centaurus association, the nearest OB association to the Sun.[11] This subgroup is the youngest of the three of the association, with an estimated age of 11 million years.[9]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 15h 54m 30.109s[1] |
| Declination | −27° 20′ 19.09″[1] |
| Apparent magnitude (V) | 6.1[2] |
| Characteristics | |
| Spectral type | B6Vp[3] |
| U−B color index | −0.44[4] |
| B−V color index | −0.07[4] |
| Astrometry | |
| Radial velocity (Rv) | −1.3[5] km/s |
| Proper motion (μ) | RA: −13.181[1] mas/yr Dec.: −25.183[1] mas/yr |
| Parallax (π) | 6.7131 ± 0.0263 mas[1] |
| Distance | 486 ± 2 ly (149.0 ± 0.6 pc) |
| Absolute magnitude (MV) | −0.1[6] |
| Absolute bolometric magnitude (Mbol) | −0.72±0.20[7] |
| Details | |
| Mass | 3.74±0.10[3] M☉ |
| Radius | 2.7 R☉ |
| Luminosity | 220+38 −33[3] L☉ |
| Surface gravity (log g) | 4.32[6] cgs |
| Temperature | 13,646±94[3] K |
| Rotational velocity (v sin i) | 34.0±1.3[8] km/s |
| Age | 11±2[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a B-type main-sequence star with a spectral type of B6Vp and a mass estimated at 3.7 times the solar mass.[3] HIP 77900 is a helium-weak chemically peculiar star, and has a magnetic field and a slow rate of rotation, with a projected rotational velocity (v sin i) of 34 km/s.[8][4] Its photosphere is radiating light with a luminosity 220 times greater the Sun's at an effective temperature of 13,600 K.[3]
Substellar companion
editStars in young stellar associations are frequent targets for direct imaging searches for sub-stellar objects, because these objects lose luminosity with time. A 2013 article, using data from the Pan-STARRS and UKIDSS surveys and follow up observations with the IRTF telescope, presented the discovery of an object of spectral type M9 and effective temperature of 2400 ± 150 K separated from HIP 77900 by 21.8 arcseconds, or more than 3200 ± 300 AU at the system's distance. Its mass, estimated from evolutionary models and assuming an age of 10 million years, is 20+7
−3 Jupiter masses, so the object is probably a low mass brown dwarf. The physical association between the two bodies has not been confirmed through common proper motion observation, but is considered likely given the proximity of the two objects in the sky and that the probable brown dwarf shows signs of youth.[7]
A 2023 survey, using data from the Gaia spacecraft, refined the parameters of this substellar companion.[12] It was found to have a mass of 21±1 MJ, a temperature of 2,507+16
−5 K and to be separated from HIP 77900 by a distance of 3,319±28 AU. It is now included in the NASA Exoplanet Archive since its mass is below their upper mass limit of 30 MJ.[13][14]
References
edit- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ Hoffleit, D.; Jaschek, C., eds. (1991). The Bright Star Catalogue. New Haven: Yale University Observatory. Bibcode:1991bsc..book.....H.
- ^ a b c d e f Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy & Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. S2CID 55586789.
- ^ a b c Renson, P.; Manfroid, J. (May 2009). "Catalogue of Ap, HgMn and Am stars". Astronomy and Astrophysics. 498 (3): 961–966. Bibcode:2009A&A...498..961R. doi:10.1051/0004-6361/200810788.
- ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
- ^ a b de Geus, E. J.; de Zeeuw, P. T.; Lub, J. (June 1989). "Physical parameters of stars in the Scorpio-Centaurus OB association". Astronomy and Astrophysics. 216 (1–2): 44–61. Bibcode:1989A&A...216...44D.
- ^ a b Aller, Kimberly M.; et al. (August 2013). "A Pan-STARRS + UKIDSS Search for Young, Wide Planetary-mass Companions in Upper Scorpius". The Astrophysical Journal. 773 (1): article 63, 15 pp. arXiv:1307.0506. Bibcode:2013ApJ...773...63A. doi:10.1088/0004-637X/773/1/63. S2CID 118378127.
- ^ a b Wraight, K. T.; et al. (February 2012). "A photometric study of chemically peculiar stars with the STEREO satellites - I. Magnetic chemically peculiar stars". Monthly Notices of the Royal Astronomical Society. 420 (1): 757–772. arXiv:1110.6283. Bibcode:2012MNRAS.420..757W. doi:10.1111/j.1365-2966.2011.20090.x. S2CID 14811051.
- ^ a b Pecaut, Mark J.; Mamajek, Eric E.; Bubar, Eric J. (February 2012). "A Revised Age for Upper Scorpius and the Star Formation History among the F-type Members of the Scorpius–Centaurus OB Association". The Astrophysical Journal. 746 (2): article 154, 22 pp. arXiv:1112.1695. Bibcode:2012ApJ...746..154P. doi:10.1088/0004-637X/746/2/154. S2CID 118461108.
- ^ "HD 142250 -- Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2018-04-17.
- ^ de Zeeuw, P. T.; et al. (January 1999). "A HIPPARCOS Census of the Nearby OB Associations". The Astronomical Journal. 117 (1): 354–399. arXiv:astro-ph/9809227. Bibcode:1999AJ....117..354D. doi:10.1086/300682. S2CID 16098861.
- ^ Michel, Kai-Uwe; Mugrauer, Markus (2024-01-01). "Gaia search for (sub)stellar companions of exoplanet hosts". Monthly Notices of the Royal Astronomical Society. 527 (2): 3183–3195. Bibcode:2024MNRAS.527.3183M. doi:10.1093/mnras/stad3196. ISSN 0035-8711.
- ^ "HIP 77900 Overview". NASA Exoplanet Archive. Retrieved May 10, 2024.
- ^ "Exoplanet Criteria for Inclusion in the Archive". NASA Exoplanet Archive. Retrieved 29 May 2023.