Iota Telescopii

ι Telescopii, Latinized as Iota Telescopii and abbreviated Iota Tel, is a solitary star^[13] located in the southern constellation Telescopium. It is faintly visible to the naked eye as an orange-hued star with an apparent visual magnitude of +4.88.^[2] The star is located roughly 377 light years distant from the Solar System based on Gaia DR3 parallax measurements^[1] and it is receding with a radial velocity of 22.3 km/s.^[5] At its current distance, Iota Tel's brightness is diminished by 0.19 magnitudes^[14] due to interstellar dust and it has an absolute magnitude of −0.39.^[6]

ι Telescopii

Location of Iota Telescopii (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Telescopium
Right ascension	19h 35m 12.98634s[1]
Declination	−48° 05′ 57.1238″[1]
Apparent magnitude (V)	4.88±0.01[2]
Characteristics
Spectral type	K0 III[3]
B−V color index	+1.09[4]
Astrometry
Radial velocity (Rv)	+22.3±0.8[5] km/s
Proper motion (μ)	RA: −8.190 mas/yr[1] Dec.: −36.977 mas/yr[1]
Parallax (π)	8.6546 ± 0.1055 mas[1]
Distance	377 ± 5 ly (116 ± 1 pc)
Absolute magnitude (MV)	−0.39[6]
Details
Mass	2.53±0.19[7] M☉
Radius	19.7±1.0[8] R☉
Luminosity	172+5 −4[1] L☉
Surface gravity (log g)	1.88[9] cgs
Temperature	4,738±55[7] K
Metallicity [Fe/H]	+0.01±0.04[7] dex
Rotational velocity (v sin i)	1.8±1.3[10] km/s
Other designations
ι Tel, 64 G. Telescopii[11], CD−48° 13161, CPD−48°10202, FK5 735, GC 27025, HD 184127, HIP 96341, HR 7424, SAO 229751[12]
Database references
SIMBAD	data

This object is an aging red giant star with a stellar classification of K0 III.^[3] At present it has 2.53 times the mass of the Sun,^[7] but it has expanded to 19.7 times the radius of the Sun.^[8] It is radiating 172 times the Sun's luminosity^[1] from its swollen photosphere at an effective temperature of 4,738 K.^[7] Iota Tel has a near solar metallicity at [Fe/H] = +0.01^[7] and it spins slowly with a projected rotational velocity of 1.8 km/s.^[10]

References

1. 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.
2. 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.
3. Houk, Nancy (1978). Michigan catalogue of two-dimensional spectral types for the HD stars: Declinations −53° to −40°. Vol. 2. Bibcode:1978mcts.book.....H.
4. Cousins, A. W. J.; et al. (1966), "Photoelectric magnitudes and colours of southern stars, II", Royal Observatory Bulletins, 121: 1, Bibcode:1966RGOB..121....1C.
5. 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.
6. 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.
7. Ottoni, G.; Udry, S.; Ségransan, D.; Buldgen, G.; Lovis, C.; Eggenberger, P.; Pezzotti, C.; Adibekyan, V.; Marmier, M.; Mayor, M.; Santos, N. C.; Sousa, S. G.; Lagarde, N.; Charbonnel, C. (January 2022). "CORALIE radial-velocity search for companions around evolved stars (CASCADES): I. Sample definition and first results: Three new planets orbiting giant stars". Astronomy & Astrophysics. 657: A87. arXiv:2201.01528. Bibcode:2022A&A...657A..87O. doi:10.1051/0004-6361/202040078. eISSN 1432-0746. ISSN 0004-6361.
8. Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants. Surface brightness relations calibrated by interferometry". 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. S2CID 6077801.
9. McDonald, I.; Zijlstra, A. A.; Watson, R. A. (15 June 2017). "Fundamental parameters and infrared excesses of Tycho–Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770–791. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. eISSN 1365-2966. ISSN 0035-8711. S2CID 73594365.
10. 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.
11. 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.
12. "iot Tel". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-05.{{cite web}}: CS1 maint: postscript (link)
13. 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. S2CID 14878976.
14. 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. S2CID 118879856.