Astronomy:Iota Crateris
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Crater |
| Right ascension | 11h 38m 40.01668s[1] |
| Declination | −13° 12′ 06.9963″[1] |
| Apparent magnitude (V) | 5.48[2] |
| Characteristics | |
| Spectral type | F6.5 V[3] |
| B−V color index | +0.52[2] |
| Astrometry | |
| Radial velocity (Rv) | −26.6±0.3[4] km/s |
| Proper motion (μ) | RA: +99.52[1] mas/yr Dec.: +125.99[1] mas/yr |
| Parallax (π) | 37.41 ± 0.30[1] mas |
| Distance | 87.2 ± 0.7 ly (26.7 ± 0.2 pc) |
| Absolute magnitude (MV) | +3.33[5] |
| Details | |
| ι Crt A | |
| Mass | 1.19+0.06 −0.02[6] M☉ |
| Surface gravity (log g) | 4.27±0.03[7] cgs |
| Temperature | 6,230±21[7] K |
| Metallicity [Fe/H] | −0.15±0.01[7] dex |
| Age | 4.45+0.32 −0.94[6] Gyr |
| ι Crt B | |
| Mass | 0.57[8] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
| C | |
Iota Crateris (ι Crateris) is the Bayer designation for a triple star[10] system in the southern constellation of Crater. It is faintly visible to the naked eye with an apparent visual magnitude of 5.48.[2] According to the Bortle scale, this means it can be viewed from suburban skies at night. Based upon an annual parallax shift of 37.41 mas,[1] Iota Crateris is located 87 light years from the Sun.
This is an astrometric binary system with an estimated orbital period of roughly 79,000 years.[10] The primary, component A, is an F-type main sequence star with a stellar classification of F6.5 V,[3] which is generating energy through the thermonuclear fusion of hydrogen in its core region. It is around 4.45[6] billion years old with 1.19[6] times the mass of the Sun. The star is radiating energy from its outer atmosphere at an effective temperature of 6,230 K.[7]
The close companion, component B, is a red dwarf star with a probable classification of M3, although its mass estimate of 0.57 solar would be more consistent with an M0 class star.[8] As of 2014, this magnitude 11.0 star had an angular separation of 1.10 arc seconds along a position angle of 248°.[11] It has a projected separation of 25 AU,[8] which means it is positioned at least this distance away from the primary.
A white dwarf 92″ away is at the same distance and shares a common proper motion with the other two stars. It is referred to as component C of the system, but has the separate designation UCAC4 384-059519.[12]
SETI observations
In 2023, Ma et al. identified a narrowband radio signal of interest in the direction of Iota Crateris, designated MLc6, from a deep learning-based technosignature search of 820 nearby stars conducted with the Robert C. Byrd Green Bank Telescope as part of the Breakthrough Listen program.[13] The signal was found in archival 2016 observations at a frequency of 1435.940 MHz, with a Doppler drift rate of −0.18 Hz s−1 and a signal-to-noise ratio of approximately 40, and was one of eight candidate signals identified across the full survey.[13] Follow-up re-observations in May 2022 did not recover the signal, indicating it is not persistent in time.[13]
An independent analysis by Margot et al. (2023) could not process the signal with their pipeline, as its drift rate exceeded the operational range of their search algorithm when applied to the available reduced data products; the authors noted it might have been recoverable had the original raw voltage data been preserved.[14] Of the five candidate signals from the same survey that their pipeline did process, all were identified as radio frequency interference.[14]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 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.
- ↑ 2.0 2.1 2.2 Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa 27: 11, Bibcode: 1968MNSSA..27...11C.
- ↑ 3.0 3.1 Gray, R. O. et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal 132 (1): 161–170, doi:10.1086/504637, Bibcode: 2006AJ....132..161G.
- ↑ 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.
- ↑ Lambert, David L.; Reddy, Bacham E. (April 2004), "Lithium abundances of the local thin disc stars", Monthly Notices of the Royal Astronomical Society 349 (2): 757−767, doi:10.1111/j.1365-2966.2004.07557.x, Bibcode: 2004MNRAS.349..757L.
- ↑ 6.0 6.1 6.2 6.3 Ramírez, I. et al. (September 2012), "Lithium Abundances in nearby FGK Dwarf and Subgiant Stars: Internal Destruction, Galactic Chemical Evolution, and Exoplanets", The Astrophysical Journal 756 (1): 46, doi:10.1088/0004-637X/756/1/46, Bibcode: 2012ApJ...756...46R.
- ↑ 7.0 7.1 7.2 7.3 Adibekyan, V. et al. (August 2016), "Abundance trend with condensation temperature for stars with different Galactic birth places", Astronomy & Astrophysics 592: 12, doi:10.1051/0004-6361/201628883, A87, Bibcode: 2016A&A...592A..87A.
- ↑ 8.0 8.1 8.2 Ehrenreich, D. et al. (November 2010), "Deep infrared imaging of close companions to austral A- and F-type stars", Astronomy and Astrophysics 523: 41, doi:10.1051/0004-6361/201014763, A73, Bibcode: 2010A&A...523A..73E.
- ↑ "iot Crt -- Star", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=iot+Crt, retrieved 2017-02-26.
- ↑ 10.0 10.1 Tokovinin, Andrei (2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal 147 (4): 14, doi:10.1088/0004-6256/147/4/87, 87, Bibcode: 2014AJ....147...87T.
- ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M.
- ↑ 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.
- ↑ 13.0 13.1 13.2 Ma, Peter Xiangyuan; Ng, Cherry; Rizk, Leandro; Croft, Steve; Siemion, Andrew P. V.; Brzycki, Bryan; Czech, Daniel; Drew, Jamie et al. (2023), "A deep-learning search for technosignatures from 820 nearby stars", Nature Astronomy 7: 492, doi:10.1038/s41550-022-01872-z, Bibcode: 2023NatAs...7..492M, https://seti.berkeley.edu/ml_gbt/MLSETI_NatAstron_arxiv3.pdf
- ↑ 14.0 14.1 Margot, Jean-Luc et al. (2023), "A Search for Technosignatures Around 11,680 Stars with the Green Bank Telescope at 1.15-1.73 GHZ", The Astronomical Journal 166 (5): 206, doi:10.3847/1538-3881/acfda4, Bibcode: 2023AJ....166..206M.
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