Astronomy:Iota1 Normae
| Observation data {{#ifeq:J2000.0|J2000.0 (ICRS)|Epoch J2000.0 Equinox J2000.0 (ICRS)| [[History:Epoch|Epoch J2000.0]] [[Astronomy:Equinox (celestial coordinates)|Equinox J2000.0}} | |
|---|---|
| Constellation | Norma |
| ι1 Nor AB | |
| Right ascension | 16h 03m 32.08942s[1] |
| Declination | −57° 46′ 30.2641″[1] |
| Apparent magnitude (V) | 5.14 + 5.70[2] |
| ι1 Nor C | |
| Right ascension | 16h 03m 30.86534s[3] |
| Declination | −57° 46′ 35.2404″[3] |
| Apparent magnitude (V) | 8.02 (8.75 + 8.75)[2] |
| Characteristics | |
| ι1 Nor AB | |
| Spectral type | A4 V + A6 V[4] |
| ι1 Nor C | |
| Spectral type | G8V + K4V[5] |
| Variable type | suspected RS CVn[5] |
| Astrometry | |
| ι1 Nor AB | |
| Radial velocity (Rv) | −14.4±3.7[6] km/s |
| Proper motion (μ) | RA: −120.01[1] mas/yr Dec.: −82.09[1] mas/yr |
| Parallax (π) | 24.67[7] mas |
| Distance | 132.2 ly (40.54 pc) |
| ι1 Nor C | |
| Radial velocity (Rv) | −10.0±0.7[7] km/s |
| Proper motion (μ) | RA: −117.271 mas/yr Dec.: −85.238 mas/yr |
| Parallax (π) | 24.3136 ± 0.0220[3] mas |
| Distance | 134.1 ± 0.1 ly (41.13 ± 0.04 pc){{{dist_ly2}}} ly |
| Orbit[8] | |
| Primary | ι1 Nor A |
| Companion | ι1 Nor B |
| Period (P) | 26.84±0.09 yr |
| Semi-major axis (a) | 0.328±0.006″ |
| Eccentricity (e) | 0.515±0.012 |
| Inclination (i) | 168.7±9.9° |
| Longitude of the node (Ω) | 42.0±43.2° |
| Periastron epoch (T) | 1990.87±0.21 |
| Argument of periastron (ω) (secondary) | 320.0±44.1° |
| Orbit[7] | |
| Primary | ι1 Nor Ca |
| Companion | ι1 Nor Cb |
| Period (P) | 0.82346(1) days |
| Semi-major axis (a) | 0.512 mas[2] |
| Eccentricity (e) | 0 (assumed) |
| Inclination (i) | ~45° |
| Argument of periastron (ω) (secondary) | 0 (assumed)° |
| Semi-amplitude (K1) (primary) | 107.0±1.2 km/s |
| Semi-amplitude (K2) (secondary) | 124.7±2.1 km/s |
| Details | |
| ι1 Nor A | |
| Mass | 1.75[2] M☉ |
| ι1 Nor B | |
| Mass | 1.54[2] M☉ |
| ι1 Nor Ca | |
| Mass | 0.88[2] M☉ |
| ι1 Nor Cb | |
| Mass | 0.88[2] M☉ |
| Other designations | |
| AB: HD 143474, HIP 78662, SAO 243279 | |
| C: SAO 243278 | |
| Database references | |
| SIMBAD | data |
| C | |
Iota1 Normae (ι1 Normae) is a quadruple star system[7] in the southern constellation of Norma. With a combined apparent visual magnitude of 4.63,[2] it is faintly visible to the naked eye. Stellar parallax measurements give distances varying between 132.2 and 134.1 light-years. At that distance, the visual magnitude of these stars is diminished by an extinction of 0.062 magnitudes due to interstellar dust.[10]
The inner pair orbit each other with a period of 26.8 years, a semimajor axis of 0.33 arc seconds, and an eccentricity of 0.515. Both stars are A-type main sequence stars. The brighter of the pair, magnitude 5.14[2] component A, has a spectral class of A4 V,[4] while its magnitude 5.70[2] companion, component B, is of class A6 V.[4] The two are 1.94 and 1.65 times as massive as the Sun, respectively.[10] The tertiary member, component C, lies at an angular separation of 11.0 arc seconds from the other members.[2] It has an apparent magnitude of 8.02[2] and is itself a close binary, comprising two stars with an orbital period around 0.82 days,[7] each with an apparent magnitude of 8.75.[2]
References
- ↑ 1.0 1.1 1.2 1.3 van Leeuwen, F. (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.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 Tokovinin, Andrei (2018-03-01), "The Updated Multiple Star Catalog", The Astrophysical Journal Supplement Series 235 (1): 6, doi:10.3847/1538-4365/aaa1a5, ISSN 0067-0049, Bibcode: 2018ApJS..235....6T. Iota' Normae's database entry at VizieR.
- ↑ 3.0 3.1 3.2 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.
- ↑ 4.0 4.1 4.2 Edwards, T. W. (April 1976), "MK classification for visual binary components", Astronomical Journal 81: 245–249, doi:10.1086/111879, Bibcode: 1976AJ.....81..245E
- ↑ 5.0 5.1 Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017), "General catalogue of variable stars: Version GCVS 5.1", Astronomy Reports 61 (1): 80–88, doi:10.1134/S1063772917010085, ISSN 1063-7729, Bibcode: 2017ARep...61...80S.
- ↑ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ 7.0 7.1 7.2 7.3 7.4 Tokovinin, Andrei (2025-07-09). "Spectroscopic Orbits of Subsystems in Multiple Stars. XI". The Astronomical Journal 170 (3): 143. doi:10.3847/1538-3881/adee23. Bibcode: 2025AJ....170..143T.
- ↑ Tokovinin, Andrei et al. (August 2015), "Speckle Interferometry at SOAR in 2014", The Astronomical Journal 150 (2): 17, doi:10.1088/0004-6256/150/2/50, 50, Bibcode: 2015AJ....150...50T.
- ↑ "iot01 Nor". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=iot01+Nor.
- ↑ 10.0 10.1 Malkov, O. Yu. et al. (2012), "Dynamical masses of a selected sample of orbital binaries", Astronomy & Astrophysics 546: A69, doi:10.1051/0004-6361/201219774, Bibcode: 2012A&A...546A..69M.
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