HD 218108

	HD 218108
Observationsdata; Epok: J2000.0
Stjärnbild	Oktanten
Rektascension	23t 08m 23,84044s
Deklination	-79° 28′ 50,4748 ″
Skenbar magnitud ()	6,11 ± 0,01
Stjärntyp
Spektraltyp	A6 Vn
U–B	+0,10
B–V	+0,14
Astrometri
Radialhastighet ()	-7 ± 4,4 km/s
Egenrörelse (µ)	RA: +93,016 mas/år; Dek.: -35,907 mas/år
Parallax ()	13,1893 ± 0,0236
Avstånd	247,3 ± 0,4 lå (75,8 ± 0,1 pc)
Absolut magnitud ()	+1,78
Detaljer
Massa	1,80 M☉
Radie	2 ± 0,1 R☉
Luminositet	15,24 L☉
Temperatur	8 213 ± 244 K
Metallicitet	-0,01
Vinkelhastighet	194 ± 2 km/s
Ålder	249 miljoner år
Andra beteckningar
	79 G. Octantis, HD 218108, CPD-80 1064, FK5 3847, GSC 09484-00065, HIC 114258, HIP 114258, HR 8786, 2MASS J23082381-7928505, PPM 375595, SAO 258105, TD1 29595, TYC 9484-65-1, uvby98 100218108, Gaia DR2 6353462490098544256, Gaia DR3 6353462490098544256

HD 218108 eller HR 8786 är en ensam stjärna belägen i den mellersta delen av stjärnbilden Oktanten. Den har en skenbar magnitud av ca 6,11^[2] och är mycket svagt synlig för blotta ögat där ljusföroreningar ej förekommer. Baserat på parallax enligt Gaia Data Release 3 på ca 13,19 mas,^[1] beräknas den befinna sig på ett avstånd på ca 247 ljusår (76 parsek) från solen. Den rör sig närmare solen med en heliocentrisk radialhastighet på ca -7 km/s.^[5] Paunzen et al. (2001) listade den som en Lambda Bootis-stjärna med svaga magnesiumlinjer i dess spektrum.^[16]

Egenskaper[redigera | redigera wikitext]

HD 218108 är en vit till blå stjärna i huvudserien av spektralklass A6 Vn,^[3] med breda eller diffusa absorptionslinjer på grund av snabb rotation (projicerad rotationshastighet 194 km/s^[12]). Den har en massa som är lika med ca 1,8^[7] solmassa, en radie som är ca 2^[8] solradier och utsänder energi från dess fotosfär motsvarande ca 15 gånger solen^[9] vid en effektiv temperatur av ca 8 200 K.^[10] Stjärnan har metallicitet ungefär samma som solens.^[11]

Referenser[redigera | redigera wikitext]

Den här artikeln är helt eller delvis baserad på material från engelskspråkiga Wikipedia, HD 218108, 20 november 2022.

Noter[redigera | redigera wikitext]

^ [a b c d e f] 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.
^ [a b] 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] Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. ISSN 0067-0049.
^ [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.
^ [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 119257644.
^ [a b c] David, Trevor J.; Hillenbrand, Lynne A. (12 May 2015). "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. eISSN 1538-4357.
^ [a b] 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.
^ [a b] McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (21 November 2012). "Fundamental parameters and infrared excesses of Hipparcos stars: Parameters and IR excesses from Hipparcos". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–357. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. eISSN 1365-2966. ISSN 0035-8711.
^ [a b] Paunzen, E.; Schnell, A.; Maitzen, H. M. (October 2006). "An empirical temperature calibration for the Δa photometric system II: The A-type and mid F-type stars". Astronomy & Astrophysics. 458 (1): 293–296. arXiv:astro-ph/0607567. Bibcode:2006A&A...458..293P. doi:10.1051/0004-6361:20064889. eISSN 1432-0746. ISSN 0004-6361.
^ [a b] Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. eISSN 1562-6873. ISSN 1063-7737.
^ [a b] Díaz, C. G.; González, J. F.; Levato, H.; Grosso, M. (July 2011). "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum". Astronomy & Astrophysics. 531: A143. arXiv:1012.4858. Bibcode:2011A&A...531A.143D. doi:10.1051/0004-6361/201016386. eISSN 1432-0746. ISSN 0004-6361.
^ 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.
^ HR 8786 (unistra.fr). Hämtad 2023-09-20.
^ "HD 218108". SIMBAD. Centre de données astronomiques de Strasbourg. Hämtad 22 oktober 2022.
^ Paunzen, E.; Duffee, B.; Heiter, U.; Kuschnig, R.; Weiss, W. W. (July 2001). "A spectroscopic survey for λ Bootis stars". Astronomy & Astrophysics. 373 (2): 625–632. Bibcode:2001A&A...373..625P. doi:10.1051/0004-6361:20010630. eISSN 1432-0746. ISSN 0004-6361.

Externa länkar[redigera | redigera wikitext]

https://www.universeguide.com/star/114258/hd218108.

[A-1] [a b c d e f] 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.

[B-2] [a b] 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.

[C-3] [a b] Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. ISSN 0067-0049.

[D-4] [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.

[E-5] [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.

[F-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.

[G-7] [a b c] David, Trevor J.; Hillenbrand, Lynne A. (12 May 2015). "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. eISSN 1538-4357.

[H-8] [a b] 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.

[I-9] [a b] McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (21 November 2012). "Fundamental parameters and infrared excesses of Hipparcos stars: Parameters and IR excesses from Hipparcos". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–357. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. eISSN 1365-2966. ISSN 0035-8711.

[K-10] [a b] Paunzen, E.; Schnell, A.; Maitzen, H. M. (October 2006). "An empirical temperature calibration for the Δa photometric system II: The A-type and mid F-type stars". Astronomy & Astrophysics. 458 (1): 293–296. arXiv:astro-ph/0607567. Bibcode:2006A&A...458..293P. doi:10.1051/0004-6361:20064889. eISSN 1432-0746. ISSN 0004-6361.

[L-11] [a b] Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. eISSN 1562-6873. ISSN 1063-7737.

[M-12] [a b] Díaz, C. G.; González, J. F.; Levato, H.; Grosso, M. (July 2011). "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum". Astronomy & Astrophysics. 531: A143. arXiv:1012.4858. Bibcode:2011A&A...531A.143D. doi:10.1051/0004-6361/201016386. eISSN 1432-0746. ISSN 0004-6361.

[N-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] HR 8786 (unistra.fr). Hämtad 2023-09-20.

[O-15] "HD 218108". SIMBAD. Centre de données astronomiques de Strasbourg. Hämtad 22 oktober 2022.

[P-16] Paunzen, E.; Duffee, B.; Heiter, U.; Kuschnig, R.; Weiss, W. W. (July 2001). "A spectroscopic survey for λ Bootis stars". Astronomy & Astrophysics. 373 (2): 625–632. Bibcode:2001A&A...373..625P. doi:10.1051/0004-6361:20010630. eISSN 1432-0746. ISSN 0004-6361.

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Observationsdata Epok: J2000.0
HD 218108

Stjärnbild	Oktanten
Rektascension	23^t 08^m 23,84044^s^[1]
Deklination	-79° 28′ 50,4748 ″^[1]
Skenbar magnitud ( $V$ )	6,11 ± 0,01^[2]
Stjärntyp
Spektraltyp	A6 Vn^[3]
U–B	+0,10^[4]
B–V	+0,14^[4]
Astrometri
Radialhastighet ( $R_{v}$ )	-7 ± 4,4^[5] km/s
Egenrörelse (µ)	RA: +93,016^[1] mas/år Dek.: -35,907^[1] mas/år
Parallax ( $\pi$ )	13,1893 ± 0,0236^[1]
Avstånd	247,3 ± 0,4 lå (75,8 ± 0,1 pc)
Absolut magnitud ( $M_{V}$ )	+1,78^[6]
Detaljer
Massa	1,80^[7] M_☉
Radie	2 ± 0,1^[8] R_☉
Luminositet	15,24^[9] L_☉
Temperatur	8 213 ± 244^[10] K
Metallicitet	-0,01^[11]
Vinkelhastighet	194 ± 2^[12] km/s
Ålder	249^[7] miljoner år
Andra beteckningar
79 G. Octantis,^[13] HD 218108, CPD-80 1064, FK5 3847, GSC 09484-00065, HIC 114258, HIP 114258, HR 8786, 2MASS J23082381-7928505, PPM 375595, SAO 258105, TD1 29595, TYC 9484-65-1, uvby98 100218108, Gaia DR2 6353462490098544256, Gaia DR3 6353462490098544256^[14]^[15]