AD Leonis

	AD Leonis
Observationsdata; Epok: J2000.0
Stjärnbild	Lejonet
Rektascension	10t 19m 36,277 s
Deklination	+19° 52′ 12,06 ″
Skenbar magnitud ()	+9,32
Stjärntyp
Spektraltyp	M3.5 eV
U–B	+1,06
B–V	+1,54
Variabeltyp	Flarestjärna
Astrometri
Radialhastighet ()	+10,8 km/s
Egenrörelse (µ)	RA: -501,8 mas/år; Dek.: -42,8 ± 0,10 mas/år
Parallax ()	201,4064 ± 0,0269
Avstånd	16,194 ± 0,002 lå (4,9651 ± 0,0007 pc)
Absolut magnitud ()	+10,87
Detaljer
Massa	0,39 - 0,42 M☉
Radie	0,39 R☉
Luminositet	0,024 L☉
Temperatur	3 390 ± 19 K
Metallicitet	+0,28 ± 0,17
Vinkelhastighet	3 km/s
Ålder	25 - 300 miljoner år
Andra beteckningar
	BD+20 2465, AG+20 1170, AP J10193634+1952122, CCDM J10199+1951C, 2E 2259, EUVE J1019+19.8, G 54-23, GJ 388, IRAS 10169+2007, LHS 5167, LSPM J1019+1952, 2MASS J10193634+1952122, NLTT 24015, PLX 2420, PPM 127309, 2RE J101936+195209, 2RE J1019+195, 1RXS J101936.3+195215, SAO 81292, TYC 1423-174-1, UCAC2 38796273, UCAC4 550-048962, USNO-B1.0 1098-00182796, AD Leonis, WISEA J101935.88+195211.9, [GKL99] 216, Gaia DR3 625453654702751872, Gaia DR2 625453654702751872

AD Leonis är en ensam stjärna i mellersta delen av stjärnbilden Lejonet. Den har en skenbar magnitud av ca 9,32^[2] och kräver åtminstone ett mindre teleskop för att kunna observeras. Baserat på parallax enligt Gaia Data Release 3 på ca 201,4 mas,^[6] beräknas den befinna sig på ett avstånd på ca 16,2 ljusår (ca 4,97 parsek) från solen. Den rör sig bort från solen med en heliocentrisk radialhastighet på 11 km/s.^[5]

Egenskaper

AD Leonis är en röd stjärna i huvudserien av spektralklass M3.5 eV^[3] och är en flarestjärna, som har slumpmässiga ökningar i ljusstyrka.^[4]^[14] Den har en massa som är ca 0,4^[7]^[8] solmassa, en radie som är ca 0,39^[8] solradie och har ca 0,024^[1] gånger solens utstrålning av energi från dess fotosfär vid en effektiv temperatur av ca 3 400 K.^[10] Stjärnan är relativt ung med en uppskattad ålder på 25–300 miljoner år,^[12] och anses ingå i den unga diskpopulationen.^[15]

U, B, V och R ljuskurvor för en flare på *AD Leonis*, anpassad från Hawley och Pettersen (1991)^[16]

Stjärnans varierande karaktär observerades första gången 1949 av Katherine C. Gordon och Gerald E. Kron vid Lick Observatory.^[17] AD Leonis är en av de mest aktiva flarestjärnorna som är kända, och emissionerna från flares har visats över det elektromagnetiska spektrumet så högt som röntgenbandet.^[18]^[19] Det magnetiska nettoflödet vid ytan är cirka 3 kG.^[11] Förutom stjärnfläckar är cirka 73 procent av ytan täckt av magnetiskt aktiva områden.^[20] Undersökning av koronan i röntgenvåglängd visar kompakta slingstrukturer som spänner över upp till 30 procent av stjärnans storlek.^[21] Medeltemperaturen för koronan är cirka 6,39 megakelvin.^[22] År 2021 observerades en superflare på AD Leonis samtidigt i röntgenområdet av XMM-Newton och i optiska bandet av TESS.^[23]

Referenser

Den här artikeln är helt eller delvis baserad på material från engelskspråkiga Wikipedia, AD Leonis, 13 maj 2023..

Noter

^ [a b c d e] Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862.
^ [a b c d] Nicolet, B. (October 1978). "Catalogue of homogeneous data in the UBV photoelectric photometric system". Astronomy and Astrophysics Supplement Series. 34: 1–49. Bibcode:1978A&AS...34....1N.
^ [a b] Shkolnik, Evgenya; Liu, Michael C.; Reid, I. Neill (July 2009). "Identifying the young low-mass stars within 25 pc. I. Spectroscopic observations". The Astrophysical Journal. 699 (1): 649–666. arXiv:0904.3323. Bibcode:2009ApJ...699..649S. doi:10.1088/0004-637X/699/1/649. S2CID 118623086.
^ [a b] Kukarkin, B. V.; Kholopov, P. N.; Pskovsky, Y. P.; Efremov, Y. N.; Kukarkina, N. P.; Kurochkin, N. E.; Medvedeva, G. I. (1971). "The third edition, containing information on 20,437 variable stars discovered and designated till 1968". General Catalogue of Variable Stars (3rd ed.). Bibcode:1971GCVS3.C......0K.
^ [a b] Evans, D. S. (20–24 June 1966). "The revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. Bibcode:1967IAUS...30...57E.
^ [a b] 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] "The One Hundred Nearest Star Systems". Georgia State University. 1 January 2009. Hämtad 25 september 2009.
^ [a b c d e] Reiners, Ansgar; Basri, Gibor; Browning, Matthew (February 2009). "Evidence for magnetic flux saturation in rapidly rotating M stars" (PDF). The Astrophysical Journal. 692 (1): 538–545. arXiv:0810.5139. Bibcode:2009ApJ...692..538R. doi:10.1088/0004-637X/692/1/538. hdl:10871/10302. S2CID 15833388.
^ Pettersen, B. R.; Coleman, L. A. (December 1981). "Chromospheric lines in red dwarf flare stars, I - AD Leonis and GX Andromedae". Astrophysical Journal. 251 (12): 571–82. Bibcode:1981ApJ...251..571P. doi:10.1086/159500.
^ [a b c] Rojas-Ayala, Bárbara; Covey, Kevin R.; Muirhead, Philip S.; Lloyd, James P. (April 2012). "Metallicity and temperature indicators in M dwarf K band spectra: Testing new and updated calibrations with observations of 133 Solar neighborhood M dwarfs". The Astrophysical Journal. 748 (2): 93. arXiv:1112.4567. Bibcode:2012ApJ...748...93R. doi:10.1088/0004-637X/748/2/93. S2CID 41902340.
^ [a b] Reiners, Ansgar (May 2007). "The narrowest M dwarf line profiles and the rotation-activity connection at very slow rotation". Astronomy and Astrophysics. 467 (1): 259–268. arXiv:astro-ph/0702634. Bibcode:2007A&A...467..259R. doi:10.1051/0004-6361:20066991. S2CID 8672566.
^ [a b] Shkolnik, Evgenya; Liu, Michael C.; Reid, I. Neill (July 2009). "Identifying the young low-mass stars within 25 pc. I. Spectroscopic observations". The Astrophysical Journal. 699 (1): 649–666. arXiv:0904.3323. Bibcode:2009ApJ...699..649S. doi:10.1088/0004-637X/699/1/649. S2CID 118623086.
^ TYC 1423-174-1 (unistra.fr). Hämtad 2023-05-24.
^ [a b] "V* AD Leo – Flare Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Hämtad 25 september 2009.
^ Sciortino, S.; Maggio, A.; Favata, F.; Orlando, S. (February 1999). "X-ray spectroscopy of the active dM stars: AD Leo and EV Lac". Astronomy & Astrophysics. 342 (2): 502–14. Bibcode:1999A&A...342..502S.
^ Hawley, Suzanne L.; Pettersen, Bjorn R. (September 1991). "The Great Flare of 1985 April 12 on AD Leonis". The Astrophysical Journal. 378: 725. Bibcode:1991ApJ...378..725H. doi:10.1086/170474. Hämtad 17 januari 2022.
^ Gordon, Katherine C.; Kron, Gerald E. (October 1949). "Flare of a dMe star, BD+20°2465, observed photoelectrically". Publications of the Astronomical Society of the Pacific. 61 (362): 210–214. Bibcode:1949PASP...61..210G. doi:10.1086/126179.
^ Osten, Rachel A.; Bastian, T. S. (February 2008). "Ultra-high time resolution observations of radio bursts on AD Leonis". The Astrophysical Journal. 674 (2): 1078–1085. arXiv:0710.5881. Bibcode:2008ApJ...674.1078O. doi:10.1086/525013. S2CID 6953897.
^ Schmitt, Jürgen H. M. M.; Fleming, T. A.; Giampapa, M. S. (September 1995). "The X-ray view of the low-mass stars in the solar neighborhood". Astrophysical Journal. 450 (9): 392–400. Bibcode:1995ApJ...450..392S. doi:10.1086/176149.
^ Crespo-Chacón, I.; Montes, D.; García-Alvarez, D.; Fernández-Figueroa, M. J.; López-Santiago, J.; Foing, B. H. (June 2006). "Analysis and modeling of high temporal resolution spectroscopic observations of flares on AD Leonis". Astronomy and Astrophysics. 452 (3): 987–1000. arXiv:astro-ph/0602123. Bibcode:2006A&A...452..987C. doi:10.1051/0004-6361:20053615. S2CID 119092601.
^ Christian, D. J.; Mathioudakis, M.; Bloomfield, D. S.; Dupuis, J.; Keenan, F. P.; Pollacco, D. L.; Malina, R. F. (August 2006). "Opacity in the upper atmospheres of active stars. II. AD Leonis" (PDF). Astronomy and Astrophysics. 454 (3): 889–894. arXiv:astro-ph/0602447. Bibcode:2006A&A...454..889C. doi:10.1051/0004-6361:20054404. S2CID 29588514.
^ Johnstone, C. P.; Güdel, M. (June 2015). "The coronal temperatures of low-mass main-sequence stars". Astronomy & Astrophysics. 578: 4. arXiv:1505.00643. Bibcode:2015A&A...578A.129J. doi:10.1051/0004-6361/201425283. S2CID 117151984. A129.
^ Stelzer, B.; Caramazza, M.; Raetz, St.; Argiroffi, C.; Coffaro, M. (2022). "The Great Flare of 2021 November 19 on AD Leo. Simultaneous XMM-Newton and TESS observations". Solar and Stellar Astrophysics. arXiv:2209.05068. doi:10.1051/0004-6361/202244642. S2CID 252199896.

Externa länkar

https://www.universeguide.com/star/122565/adleonis.

[B-1] [a b c d e] Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862.

[C-2] [a b c d] Nicolet, B. (October 1978). "Catalogue of homogeneous data in the UBV photoelectric photometric system". Astronomy and Astrophysics Supplement Series. 34: 1–49. Bibcode:1978A&AS...34....1N.

[D-3] [a b] Shkolnik, Evgenya; Liu, Michael C.; Reid, I. Neill (July 2009). "Identifying the young low-mass stars within 25 pc. I. Spectroscopic observations". The Astrophysical Journal. 699 (1): 649–666. arXiv:0904.3323. Bibcode:2009ApJ...699..649S. doi:10.1088/0004-637X/699/1/649. S2CID 118623086.

[E-4] [a b] Kukarkin, B. V.; Kholopov, P. N.; Pskovsky, Y. P.; Efremov, Y. N.; Kukarkina, N. P.; Kurochkin, N. E.; Medvedeva, G. I. (1971). "The third edition, containing information on 20,437 variable stars discovered and designated till 1968". General Catalogue of Variable Stars (3rd ed.). Bibcode:1971GCVS3.C......0K.

[F-5] [a b] Evans, D. S. (20–24 June 1966). "The revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. Bibcode:1967IAUS...30...57E.

[G-6] [a b] 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.

[H-7] [a b c] "The One Hundred Nearest Star Systems". Georgia State University. 1 January 2009. Hämtad 25 september 2009.

[I-8] [a b c d e] Reiners, Ansgar; Basri, Gibor; Browning, Matthew (February 2009). "Evidence for magnetic flux saturation in rapidly rotating M stars" (PDF). The Astrophysical Journal. 692 (1): 538–545. arXiv:0810.5139. Bibcode:2009ApJ...692..538R. doi:10.1088/0004-637X/692/1/538. hdl:10871/10302. S2CID 15833388.

[J-9] Pettersen, B. R.; Coleman, L. A. (December 1981). "Chromospheric lines in red dwarf flare stars, I - AD Leonis and GX Andromedae". Astrophysical Journal. 251 (12): 571–82. Bibcode:1981ApJ...251..571P. doi:10.1086/159500.

[K-10] [a b c] Rojas-Ayala, Bárbara; Covey, Kevin R.; Muirhead, Philip S.; Lloyd, James P. (April 2012). "Metallicity and temperature indicators in M dwarf K band spectra: Testing new and updated calibrations with observations of 133 Solar neighborhood M dwarfs". The Astrophysical Journal. 748 (2): 93. arXiv:1112.4567. Bibcode:2012ApJ...748...93R. doi:10.1088/0004-637X/748/2/93. S2CID 41902340.

[L-11] [a b] Reiners, Ansgar (May 2007). "The narrowest M dwarf line profiles and the rotation-activity connection at very slow rotation". Astronomy and Astrophysics. 467 (1): 259–268. arXiv:astro-ph/0702634. Bibcode:2007A&A...467..259R. doi:10.1051/0004-6361:20066991. S2CID 8672566.

[M-12] [a b] Shkolnik, Evgenya; Liu, Michael C.; Reid, I. Neill (July 2009). "Identifying the young low-mass stars within 25 pc. I. Spectroscopic observations". The Astrophysical Journal. 699 (1): 649–666. arXiv:0904.3323. Bibcode:2009ApJ...699..649S. doi:10.1088/0004-637X/699/1/649. S2CID 118623086.

[SIMBAD-13] TYC 1423-174-1 (unistra.fr). Hämtad 2023-05-24.

[N-14] [a b] "V* AD Leo – Flare Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Hämtad 25 september 2009.

[P-15] Sciortino, S.; Maggio, A.; Favata, F.; Orlando, S. (February 1999). "X-ray spectroscopy of the active dM stars: AD Leo and EV Lac". Astronomy & Astrophysics. 342 (2): 502–14. Bibcode:1999A&A...342..502S.

[A-16] Hawley, Suzanne L.; Pettersen, Bjorn R. (September 1991). "The Great Flare of 1985 April 12 on AD Leonis". The Astrophysical Journal. 378: 725. Bibcode:1991ApJ...378..725H. doi:10.1086/170474. Hämtad 17 januari 2022.

[Q-17] Gordon, Katherine C.; Kron, Gerald E. (October 1949). "Flare of a dMe star, BD+20°2465, observed photoelectrically". Publications of the Astronomical Society of the Pacific. 61 (362): 210–214. Bibcode:1949PASP...61..210G. doi:10.1086/126179.

[R-18] Osten, Rachel A.; Bastian, T. S. (February 2008). "Ultra-high time resolution observations of radio bursts on AD Leonis". The Astrophysical Journal. 674 (2): 1078–1085. arXiv:0710.5881. Bibcode:2008ApJ...674.1078O. doi:10.1086/525013. S2CID 6953897.

[S-19] Schmitt, Jürgen H. M. M.; Fleming, T. A.; Giampapa, M. S. (September 1995). "The X-ray view of the low-mass stars in the solar neighborhood". Astrophysical Journal. 450 (9): 392–400. Bibcode:1995ApJ...450..392S. doi:10.1086/176149.

[T-20] Crespo-Chacón, I.; Montes, D.; García-Alvarez, D.; Fernández-Figueroa, M. J.; López-Santiago, J.; Foing, B. H. (June 2006). "Analysis and modeling of high temporal resolution spectroscopic observations of flares on AD Leonis". Astronomy and Astrophysics. 452 (3): 987–1000. arXiv:astro-ph/0602123. Bibcode:2006A&A...452..987C. doi:10.1051/0004-6361:20053615. S2CID 119092601.

[U-21] Christian, D. J.; Mathioudakis, M.; Bloomfield, D. S.; Dupuis, J.; Keenan, F. P.; Pollacco, D. L.; Malina, R. F. (August 2006). "Opacity in the upper atmospheres of active stars. II. AD Leonis" (PDF). Astronomy and Astrophysics. 454 (3): 889–894. arXiv:astro-ph/0602447. Bibcode:2006A&A...454..889C. doi:10.1051/0004-6361:20054404. S2CID 29588514.

[V-22] Johnstone, C. P.; Güdel, M. (June 2015). "The coronal temperatures of low-mass main-sequence stars". Astronomy & Astrophysics. 578: 4. arXiv:1505.00643. Bibcode:2015A&A...578A.129J. doi:10.1051/0004-6361/201425283. S2CID 117151984. A129.

[O-23] Stelzer, B.; Caramazza, M.; Raetz, St.; Argiroffi, C.; Coffaro, M. (2022). "The Great Flare of 2021 November 19 on AD Leo. Simultaneous XMM-Newton and TESS observations". Solar and Stellar Astrophysics. arXiv:2209.05068. doi:10.1051/0004-6361/202244642. S2CID 252199896.

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AD Leonis

Egenskaper

Referenser

Noter

Externa länkar

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