location of HD 154556 in red | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Apus |
| Right ascension | 17 12 19.93421 |
| Declination | −70° 43′ 15.8963″ |
| Apparent magnitude (V) | 6.21±0.01 |
| Characteristics | |
| Evolutionary stage | subgiant |
| Spectral type | K1 IV CN3 |
| U−B color index | +1.04 |
| B−V color index | +1.06 |
| Astrometry | |
| Radial velocity (Rv) | −24±0.4 km/s |
| Proper motion (μ) | RA: +49.060 mas/yr Dec.: −78.104 mas/yr |
| Parallax (π) | 14.3386 ± 0.0224 mas |
| Distance | 227.5 ± 0.4 ly (69.7 ± 0.1 pc) |
| Absolute magnitude (MV) | +2.10 |
| Details | |
| Mass | 1.25 M☉ |
| Radius | 6.35±0.32 R☉ |
| Luminosity | 19.7±0.1 L☉ |
| Surface gravity (log g) | 2.90±0.25 cgs |
| Temperature | 4,677 K |
| Metallicity | +0.04±0.09 dex |
| Rotational velocity (v sin i) | <1 km/s |
| Age | 3.52 −0.37 Gyr |
| Other designations | |
| 55 G. Apodis[12], CD−70°1498, CPD−70°2361, GC 23140, HD 154556, HIP 84158, HR 6357, SAO 257472 | |
| Database references | |
| SIMBAD | data |
HD 154556, also known as HR 6357, is a solitary orange-hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.21, placing it near the limit for naked eye visibility. The star is located relatively close at a distance of 228 light years based on Gaia DR3 parallax measurements, but it is drifter closer with a heliocentric radial velocity of −24 km/s. At its current distance, HD 154556's brightness is diminished by 0.26 magnitudes due to interstellar dust. It has an absolute magnitude of +2.10.
HD 154556 has a stellar classification of K1 IV CN3, indicating that it is an evolved K-type subgiant with a moderate abundance of cyano radicals in its spectrum, making it a CN star. It has 1.25 times the mass of the Sun and is calculated to be 3.52 billion years old, having expanded to 6.35 times the radius of the Sun. It now radiates 19.7 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,677 K. It has a near solar metallicity and spins slowly with a projected rotational velocity lower than 1 km/s.
References
- ^ 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.
- ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27 – L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
- ^ Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations −90° to −53°. Bibcode:1975mcts.book.....H.
- ^ Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.
- ^ Gontcharov, G. A. (November 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. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
- ^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
- ^ Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. eISSN 1432-0746. ISSN 0004-6361.
- ^ Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". Astronomy & Astrophysics. 426 (1): 297–307. arXiv:astro-ph/0404180. Bibcode:2004A&A...426..297K. doi:10.1051/0004-6361:20035930. eISSN 1432-0746. ISSN 0004-6361.
- ^ Randich, S.; Gratton, R.; Pallavicini, R.; Pasquini, L.; Carretta, E. (August 1999). "Lithium in population I subgiants". Astronomy and Astrophysics. 348: 487–500. Bibcode:1999A&A...348..487R. ISSN 0004-6361.
- ^ Allende Prieto, C.; Lambert, D. L. (December 1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. ISSN 0004-6361.
- ^ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars V: Southern stars". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. eISSN 1432-0746. ISSN 0004-6361. S2CID 54046583.
- Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
- "HD 154556". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 20 September 2015.
- Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711.
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