HD 198357

	HD 198357
Observationsdata; Epok: J2000.0
Stjärnbild	Mikroskopet
Rektascension	20t 51m 00,75817s
Deklination	-37° 54′ 47,9922″
Skenbar magnitud ()	+5,50 ± 0,01
Stjärntyp
Spektraltyp	K3 III eller K3 II
B–V	+1,38
Astrometri
Radialhastighet ()	+16,5 ± 2,9 km/s
Egenrörelse (µ)	RA: -7,436 mas/år; Dek.: -17,374 mas/år
Parallax ()	5,7348 ± 0,0797
Avstånd	569 ± 8 lå (174 ± 2 pc)
Absolut magnitud ()	-0,75
Detaljer
Massa	1,81 ± 0,44 M☉
Radie	37,8 ± 1,9 R☉
Luminositet	417 +16−15 L☉
Temperatur	4 318 ± 51 K
Metallicitet	-0,12 dex
Vinkelhastighet	<1,0 km/s
Andra beteckningar
	28 G. Microscopii, HD 198357, CD-38 14250, CPD-38 8121, GC 29053, GSC 07964-00689, HIC 102916, HIP 102916, HR 7971, IRAS 20478-3806, 2MASS J20510075-3754479, PPM 300690, RAVE J205100.8-375448, SAO 212488, TYC 7964-689-1, Gaia DR2 6777965134807570560, Gaia DR3 6777965134807570560

HD 198357 (HR 7971; 28 G. Microscopii) är en ensam stjärna i stjärnbilden Mikroskopet. Den är svagt synlig för blotta ögat som en orangefärgad ljuspunkt med en skenbar magnitud av 5,50.^[3] Gaia DR3-parallaxmätningar tyder på ett avstånd på 569 ljusår^[2] från solsystemet och stjärnan rör sig bort från solen med en heliocentrisk radialhastighet på 16,5 km/s.^[7] På dess avstånd minskas HD 198357:s luminositet med 0,18 magnitud på grund av interstellär utsläckning^[16] och den har en absolut magnitud på −0,75.^[1]

Egenskaper

HD 198357 har spektralklass K3 III,^[4] vilken anger att den är en utvecklad jättestjärna av spektraltyp K. David Stanley Evans angav spektralklass K3 II, vilket anger en ljusstark jätte.^[5] Den har en massa av 1,81 solmassa^[8] men har expanderat till en radie av 37,8 solradier.^[9] Stjärnan utstrålar energi motsvarande 417 gånger solens luminositet^[2] från sin fotosfär vid en effektiv temperatur på 4 318 K.^[10] HD 198357 har en svag metallbrist med en järnhalt som är tre fjärdedelar av solens eller [Fe/H] = −0,12^[11] och den roterar för långsamt för att dess projicerade rotationshastighet ska kunna mätas korrekt.^[12] HD 198357 har en egenrörelse av 27,7 ^+3,9_−4,1 km/s, vilket tyder på att den kan vara en flyktstjärna (46 procent sannolikhet).^[17]

Referenser

Den här artikeln är helt eller delvis baserad på material från engelskspråkiga Wikipedia, HD 198357, 31 oktober 2025..

Noter

1 2 3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
1 2 3 4 5 6 7 8 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.
1 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. S2CID 17128864.
1 2 Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Declinations −40° to −26°. Vol. 3. Bibcode:1982mcts.book.....H.
1 2 Evans, D. S. (1966). "Fundamental data for Southern stars (6th list)". Royal Greenwich Observatory Bulletins. 110: 185. Bibcode:1966RGOB..110..185E.
↑ Lake, R. (1965). "Photometric Magnitudes and Colours for Bright Southern Stars (Sixth List)". Monthly Notes of the Astronomical Society of South Africa. 24: 41. Bibcode:1965MNSSA..24...41L. ISSN 0024-8266.
1 2 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.
1 2 Hohle, M.M.; Neuhäuser, R.; Schutz, B.F. (April 2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten. 331 (4): 349–360. arXiv:1003.2335. Bibcode:2010AN....331..349H. doi:10.1002/asna.200911355. eISSN 1521-3994. ISSN 0004-6337. S2CID 111387483.
1 2 Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". 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.
1 2 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. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.
1 2 Park, Sunkyung; Kang, Wonseok; Lee, Jeong-Eun; Lee, Sang-Gak (August 21, 2013). "Wilson-Bappu Effect: Extended to Surface Gravity". The Astronomical Journal. 146 (4). American Astronomical Society: 73. arXiv:1307.0592. Bibcode:2013AJ....146...73P. doi:10.1088/0004-6256/146/4/73. ISSN 0004-6256. S2CID 119187733.
1 2 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.
↑ 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.
↑ https://simbad.cds.unistra.fr/simbad/sim-id?Ident=HR+7971. Hämtad 2026-03-11.
↑ "HD 198357". SIMBAD. Centre de données astronomiques de Strasbourg. Hämtad 6 augusti 2023.
↑ 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.
↑ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (October 12, 2010). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1). Oxford University Press (OUP): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. ISSN 0035-8711. S2CID 118629873.

[A-1] 1 2 3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.

[B-2] 1 2 3 4 5 6 7 8 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.

[C-3] 1 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. S2CID 17128864.

[D-4] 1 2 Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Declinations −40° to −26°. Vol. 3. Bibcode:1982mcts.book.....H.

[E-5] 1 2 Evans, D. S. (1966). "Fundamental data for Southern stars (6th list)". Royal Greenwich Observatory Bulletins. 110: 185. Bibcode:1966RGOB..110..185E.

[F-6] Lake, R. (1965). "Photometric Magnitudes and Colours for Bright Southern Stars (Sixth List)". Monthly Notes of the Astronomical Society of South Africa. 24: 41. Bibcode:1965MNSSA..24...41L. ISSN 0024-8266.

[G-7] 1 2 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.

[H-8] 1 2 Hohle, M.M.; Neuhäuser, R.; Schutz, B.F. (April 2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten. 331 (4): 349–360. arXiv:1003.2335. Bibcode:2010AN....331..349H. doi:10.1002/asna.200911355. eISSN 1521-3994. ISSN 0004-6337. S2CID 111387483.

[I-9] 1 2 Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". 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.

[K-10] 1 2 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. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.

[J-11] 1 2 Park, Sunkyung; Kang, Wonseok; Lee, Jeong-Eun; Lee, Sang-Gak (August 21, 2013). "Wilson-Bappu Effect: Extended to Surface Gravity". The Astronomical Journal. 146 (4). American Astronomical Society: 73. arXiv:1307.0592. Bibcode:2013AJ....146...73P. doi:10.1088/0004-6256/146/4/73. ISSN 0004-6256. S2CID 119187733.

[L-12] 1 2 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.

[M-13] 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.

[SIMBAD-14] ttps://simbad.cds.unistra.fr/simbad/sim-id?Ident=HR+7971. Hämtad 2026-03-11.

[N-15] "HD 198357". SIMBAD. Centre de données astronomiques de Strasbourg. Hämtad 6 augusti 2023.

[O-16] 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.

[P-17] Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (October 12, 2010). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1). Oxford University Press (OUP): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. ISSN 0035-8711. S2CID 118629873.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

[15]

[16]

[17]

Observationsdata Epok: J2000.0
HD 198357

Stjärnbild	Mikroskopet^[1]
Rektascension	20^t 51^m 00,75817^s^[2]
Deklination	-37° 54′ 47,9922″^[2]
Skenbar magnitud ( $V$ )	+5,50 ± 0,01^[3]
Stjärntyp
Spektraltyp	K3 III^[4] eller K3 II^[5]
B–V	+1,38^[6]
Astrometri
Radialhastighet ( $R_{v}$ )	+16,5 ± 2,9^[7] km/s
Egenrörelse (µ)	RA: -7,436^[2] mas/år Dek.: -17,374^[2] mas/år
Parallax ( $\pi$ )	5,7348 ± 0,0797^[2]
Avstånd	569 ± 8 lå (174 ± 2 pc)
Absolut magnitud ( $M_{V}$ )	-0,75^[1]
Detaljer
Massa	1,81 ± 0,44^[8] M_☉
Radie	37,8 ± 1,9^[9] R_☉
Luminositet	417 ⁺¹⁶₋₁₅^[2] L_☉
Temperatur	4 318 ± 51^[10] K
Metallicitet	-0,12^[11] dex
Vinkelhastighet	<1,0^[12] km/s
Andra beteckningar
28 G. Microscopii,^[13] HD 198357, CD-38 14250, CPD-38 8121, GC 29053, GSC 07964-00689, HIC 102916, HIP 102916, HR 7971, IRAS 20478-3806, 2MASS J20510075-3754479, PPM 300690, RAVE J205100.8-375448, SAO 212488, TYC 7964-689-1, Gaia DR2 6777965134807570560, Gaia DR3 6777965134807570560^[14]^[15]