Astronomy:HD 157661
From HandWiki
Short description: Star in the constellation Ara
| Observation data {{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0 Equinox J2000.0 (ICRS)| Epoch J2000 [[Astronomy:Equinox (celestial coordinates)|Equinox J2000}} | |
|---|---|
| Constellation | Ara[1] |
| HD 157661 | |
| Right ascension | 17h 26m 51.97802s[2] |
| Declination | −45° 50′ 34.9096″[2] |
| Apparent magnitude (V) | 5.70/6.46[3] |
| HD 157649 | |
| Right ascension | 17h 26m 44.66241s[4] |
| Declination | −45° 49′ 26.0995″[4] |
| Apparent magnitude (V) | 7.11[5] |
| Characteristics | |
| HD 157661 | |
| Spectral type | B7V + B9.5V[3] |
| U−B color index | −0.34[6] |
| B−V color index | −0.07[6] |
| HD 157649 | |
| Spectral type | B9.5V[7] |
| Astrometry | |
| HD 157661 | |
| Radial velocity (Rv) | +8[8] km/s |
| Proper motion (μ) | RA: −6.46[2] mas/yr Dec.: −27.91[2] mas/yr |
| Parallax (π) | 5.13 ± 0.72[2] mas |
| Distance | approx. 640 ly (approx. 190 pc) |
| Absolute magnitude (MV) | −1.12[1] |
| HD 157649 | |
| Proper motion (μ) | RA: −5.818[4] mas/yr Dec.: −28.942[4] mas/yr |
| Parallax (π) | 5.2246 ± 0.0657[4] mas |
| Distance | 624 ± 8 ly (191 ± 2 pc) |
| Details | |
| A | |
| Mass | 3.03[9] M☉ |
| Radius | 4.49[9] R☉ |
| Luminosity | 317[9] L☉ |
| Surface gravity (log g) | 3.61[9] cgs |
| Temperature | 11,493[9] K |
| B | |
| Mass | 3.31[10] M☉ |
| HD 157649 | |
| Mass | 2.65[4] M☉ |
| Radius | 2.88[4] R☉ |
| Luminosity | 69[4] L☉ |
| Surface gravity (log g) | 3.85[4] cgs |
| Temperature | 10,189[4] K |
| Rotation | 27.152 days[11] |
| Age | 327[4] Myr |
| Other designations | |
| HD 157661: CD−45 11531, HD 157661, HIP 85389, HR 6477[12] | |
| HD 157649: CD−45 11527, HD 157649 | |
| Database references | |
| SIMBAD | data |
| A | |
| B | |
| HD 157649 | |
HD 157661 is the Henry Draper Catalogue designation for a likely triple star[3] in the southern constellation of Ara. With a measured annual parallax of 5.13 mas,[2] is located at a distance of approximately 640 light-years (200 parsecs) from Earth. The combined apparent visual magnitude of the stars is 5.29,[6] which means it is faintly visible to the naked eye.
The inner components of this system consist of a pair of B-type main sequence stars. The brighter star has a magnitude of 5.70 and a stellar classification of B7 V. At an angular separation of 2.115 arcseconds is the magnitude 6.46 secondary component, which has a classification of B9.5 V. The third member of the system is HD 157649, a 7.6 magnitude A-type star at a separation of 103 arcseconds.[3]
References
- ↑ 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 3.0 3.1 3.2 3.3 Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355. Bibcode: 2000A&A...355L..27H.
- ↑ 6.0 6.1 6.2 Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series 34: 1–49, Bibcode: 1978A&AS...34....1N.
- ↑ Corbally, C. J. (1984). "Close visual binaries.I.MK classifications". The Astrophysical Journal Supplement Series 55: 657. doi:10.1086/190973. Bibcode: 1984ApJS...55..657C.
- ↑ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, 30, University of Toronto: International Astronomical Union, p. 57, Bibcode: 1967IAUS...30...57E.
- ↑ 9.0 9.1 9.2 9.3 9.4 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S.
- ↑ Tokovinin, Andrei (2018). "The Updated Multiple Star Catalog". The Astrophysical Journal Supplement Series 235 (1): 6. doi:10.3847/1538-4365/aaa1a5. Bibcode: 2018ApJS..235....6T.
- ↑ Oelkers, Ryan J.; Rodriguez, Joseph E.; Stassun, Keivan G.; Pepper, Joshua; Somers, Garrett; Kafka, Stella; Stevens, Daniel J.; Beatty, Thomas G. et al. (2018). "Variability Properties of Four Million Sources in the TESS Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey". The Astronomical Journal 155 (1): 39. doi:10.3847/1538-3881/aa9bf4. Bibcode: 2018AJ....155...39O.
- ↑ "CCDM J17268-4550AB". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=CCDM+J17268-4550AB.
External links
- VizieR Detailed Page: HR 6477 Hoffleit, D., Warren, Jr., W. H., (1991). The Bright Star Catalogue, (5th Revised Ed), CDS.
- VizieR Detailed Page: CCDM 17268-4550 Dommanget J., (2002) Catalog of Components of Double & Multiple stars, CDS.
- Aladin previewer: Image of SV* ZI 1312
 |  |
