HD 37824 is a spectroscopic binary star system in the constellation of Orion. It has the variable-star designation V1149 Orionis (abbreviated to V1149 Ori). With an apparent magnitude of 6.59, it is near the limit for naked eye observation from Earth, faintly visible as an orange-hued dot of light under dark skies. It is located approximately 492 light-years (151 parsecs) distant according to Gaia DR3 parallax measurements, and is moving further away at a heliocentric radial velocity of 26.90 km/s.
  | |
| Observation data Epoch J2000[1] Equinox J2000[1] | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 41m 26.78779s[2] |
| Declination | +03° 46′ 40.9348″[2] |
| Apparent magnitude (V) | 6.59[3] |
| Characteristics | |
| Spectral type | K0III[3] or K1III[4] + late-F or G[3] |
| B−V color index | +1.14[5] |
| J−H color index | +0.721[6] |
| J−K color index | +0.875[6] |
| Variable type | RS CVn[7] |
| Astrometry | |
| Radial velocity (Rv) | 26.90 ± 0.3[8] km/s |
| Proper motion (μ) | RA: 34.517[2] mas/yr Dec.: 4.825[2] mas/yr |
| Parallax (π) | 6.6357 ± 0.0581 mas[2] |
| Distance | 492 ± 4 ly (151 ± 1 pc) |
| Absolute magnitude (MV) | 0.68±0.37[3] |
| Orbit[3] | |
| Primary | HD 37824 A |
| Companion | HD 37824 B |
| Period (P) | 53.57465±0.00072 d |
| Semi-major axis (a) | 19.518±0.083×106 km (minimum) |
| Eccentricity (e) | 0.0 (adopted) |
| Periastron epoch (T) | 2448625.022±0.037 |
| Details[3] | |
| HD 37824 A | |
| Mass | 1.5–2.5 M☉ |
| Radius | 12.6±2.2 R☉ |
| Luminosity | 67±23 L☉ |
| Metallicity [Fe/H] | 0.0 dex |
| Rotation | 54.1[4] |
| Rotational velocity (v sin i) | 14.9±1.0 km/s |
| Other designations | |
| Database references | |
| SIMBAD | HD 37824 |
Stellar properties
editHD 37824 is a single-lined spectroscopic binary, meaning only the light from the luminous primary can be observed in the system's spectra.[4] The two stars orbit each other in a circular orbit (eccentricity 0.0) with a period of 53.57 days. The star features prominent starspots, which are known to display the flip-flop effect; other stars that show this effect include FK Comae Berenices and HD 181809.[3]
The primary star (HD 37824 A) is a chromospherically active K-type giant star in the core helium burning phase. It has a radius of 12.6 R☉ and evolutionary models predict that its mass is 1.5–2.5 M☉. It is radiating 67±23 times the luminosity of the Sun from its photosphere. The unseen secondary, B, is estimated to have a mass of 1.10 M☉ if the orbital inclination is 90°, or 0.95–1.27 M☉ with an inclination of 60°, which makes it likely to be a late-F-type or G-type main-sequence star.[3]
Observational history
edit
In 1973, astronomers William P. Bidelman and Darrell Jack MacConnell reported the detection of Ca II H & K emission lines in the spectra of HD 37824. As such, Douglas S. Hall et al. suspected it to be a RS Canum Venaticorum variable. As expected, in 1983, the star was shown to vary in brightness by 0.11 magnitudes, with photometric and orbital periods of 52.6 and 53.6 days, respectively.[10] It was given its variable star designation in 1985.[11]
The starspots on the surface of the primary star, which are thought to cause the variability, were analyzed using photometric data taken between late 1978 and early 1990. The results were published in 1991, identifying six starspots, which each made the star dim by about 0.1 to 0.3 magnitudes and lasted for several years. The same study refined the orbital period to 53.58±0.02 days.[9]
Observations in 1992 showed a large excess of Hα emission alongside strong Ca II H & K and Hε emission lines. A follow-up study in 1997 reported a lower but still strong Hα emission, as well as a clear emission line from singly ionized helium revealed by spectral subtraction.[12] Additional observations in 2000 discovered high variability in the profile of the Hα line.[4]
See also
editReferences
edit- ^ a b "HD 37824". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 18 November 2024.
- ^ 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.
- ^ a b c d e f g h Fekel, Francis C.; Henry, Gregory W. (2005). "Chromospherically Active Stars. XXIV. The Giant, Single-lined Binaries HD 37824, HD 181809, and HD 217188". The Astronomical Journal. 129 (3): 1669–1685. Bibcode:2005AJ....129.1669F. doi:10.1086/427713. ISSN 0004-6256.
- ^ a b c d Montes, D.; Fernández-Figueroa, M. J.; De Castro, E.; Cornide, M.; Latorre, A.; Sanz-Forcada, J. (2000). "Multiwavelength optical observations of chromospherically active binary systems: III. High resolution echelle spectra from Ca ii H & K to Ca ii IRT". Astronomy and Astrophysics Supplement Series. 146 (1): 103–140. arXiv:astro-ph/0007041. Bibcode:2000A&AS..146..103M. doi:10.1051/aas:2000359. ISSN 0365-0138.
- ^ Høg, E.; et al. (February 2000). "The Tycho-2 Catalogue of the 2.5 Million Brightest Stars". Astronomy and Astrophysics. 355 (1): L27–L30. Bibcode:2000A&A...355L..27H.
- ^ a b Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
- ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
- ^ Karataş, Y.; Bilir, S.; Eker, Z.; Demircan, O. (2004). "Kinematics of chromospherically active binaries and evidence of an orbital period decrease in binary evolution". Monthly Notices of the Royal Astronomical Society. 349 (3): 1069–1092. arXiv:astro-ph/0404219. Bibcode:2004MNRAS.349.1069K. doi:10.1111/j.1365-2966.2004.07588.x.
- ^ a b Hall, Douglas S.; Fekel, Francis C.; Henry, Gregory W.; Barksdale, William S. (1991). "The 11 year history of starspots on V1149 ORI = HD 37824". The Astronomical Journal. 102: 1808. Bibcode:1991AJ....102.1808H. doi:10.1086/116004.
- ^ Hall, D. S.; Henry, G. W.; Louth, H.; Renner, T. R. (10 October 1983). "HD 37824: a New Variable Star". Information Bulletin on Variable Stars. 2409 (2409). Konkoly Observatory, Budapest: International Astronomical Union: 1. Bibcode:1983IBVS.2409....1H.
- ^ Kholopov, P. N.; Samus, N. N.; Kazarovets, E. V.; Perova, N. B. (March 1985). "The 67th Name-List of Variable Stars". Information Bulletin on Variable Stars. 2681: 1–32. Bibcode:1985IBVS.2681....1K.
- ^ Montes, D.; Fernández-Figueroa, M. J.; De Castro, E.; Sanz-Forcada, J. (1997). "Multiwavelength optical observations of chromospherically active binary systems: I. Simultaneous H α , Na i D 1 , D 2 , and He i D 3 observations". Astronomy and Astrophysics Supplement Series. 125 (2): 263–287. doi:10.1051/aas:1997374. ISSN 0365-0138.