NO Apodis is a solitary,[15] red hued variable star located in the southern circumpolar constellation Apus. It has an average apparent magnitude of 5.86,[16] allowing it to be faintly seen with the naked eye. The object is relatively far at a distance of 790 light years[1] but is drifting closer with a heliocentric radial velocity −18.3 km/s.[7]
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Apus |
| Right ascension | 17h 31m 27.4667s[1] |
| Declination | −80° 51′ 32.8761″[1] |
| Apparent magnitude (V) | 5.71-5.95[2] |
| Characteristics | |
| Evolutionary stage | AGB[3] |
| Spectral type | M3 III[4] |
| U−B color index | +1.80[5] |
| B−V color index | +1.67[5] |
| Variable type | Semiregular[6] |
| Astrometry | |
| Radial velocity (Rv) | −18.3±0.6[7] km/s |
| Proper motion (μ) | RA: −3.662 mas/yr[1] Dec.: −43.943 mas/yr[1] |
| Parallax (π) | 4.1479 ± 0.0741 mas[1] |
| Distance | 790 ± 10 ly (241 ± 4 pc) |
| Absolute magnitude (MV) | −1.32[8] |
| Details | |
| Mass | 1.63[9] M☉ |
| Radius | 107[10] R☉ |
| Luminosity | 1,408[11] L☉ |
| Surface gravity (log g) | 1.7±0.1[12] cgs |
| Temperature | 3,521±122[10] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
NO Apodis has a stellar classification of M3 III,[4] indicating that it is a red giant. It is currently on the asymptotic giant branch,[3] fusing hydrogen and helium shells around an inert carbon core. At present it has 1.63 times the mass of the Sun[9] and an enlarged radius of 107 R☉.[10] It shines with a bolometric luminosity 1,408 times that of the Sun[11] from its photosphere at an effective temperature of 3,521 K.[10]
NO Apodis is classified as a semiregular variable of unknown subtype. Observations from Tabur et. al. (2009) reveal it to have two periods, both lasting 26-7 days.[17] During this timeframe, the star flucates between 5.71 and 5.95 in the visual band.[2]
| Period | Days | Amplitude |
|---|---|---|
| 1 | 26.2 | 0.04 |
| 2 | 26.6 | 0.092 |
References
edit- ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b c Watson, Christopher (25 August 2009). "NO Apodis". The International Variable Star Index. American Association of Variable Star Observers. Retrieved 31 March 2015.
- ^ a b Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". The Astronomical Journal. 104: 275. Bibcode:1992AJ....104..275E. doi:10.1086/116239. ISSN 0004-6256.
- ^ a b 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.
- ^ a b 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.
- ^ 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. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. ISSN 1063-7729. S2CID 125853869.
- ^ a b 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 255204555.
- ^ a b Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. eISSN 1432-0746. ISSN 0004-6361.
- ^ a b c d Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256.
- ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ 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.
- ^ Gould, B. A., Uranometria Argentina, Reprinted and updated by Pilcher, F, archived from the original on 2012-02-27, retrieved 2012-01-06
- ^ "NO Aps". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved July 27, 2022.
- ^ Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. eISSN 1365-2966. ISSN 0035-8711.
- ^ 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.
- ^ a b Tabur, V.; Bedding, T. R.; Kiss, L. L.; Moon, T. T.; Szeidl, B.; Kjeldsen, H. (21 December 2009). "Long-term photometry and periods for 261 nearby pulsating M giants". Monthly Notices of the Royal Astronomical Society. 400 (4): 1945–1961. arXiv:0908.3228. Bibcode:2009MNRAS.400.1945T. doi:10.1111/j.1365-2966.2009.15588.x. eISSN 1365-2966. ISSN 0035-8711.