RT Virginis

	RT Virginis
Observationsdata; Epok: J2000.0
Stjärnbild	Jungfrun
Rektascension	13t 02m 37,981s
Deklination	+05° 11′ 08,36″
Skenbar magnitud ()	+7,7 - 9,7
Stjärntyp
Spektraltyp	M8 III
B–V	+1,352 ± 0,031
Variabeltyp	Halvregelbunden variabel
Astrometri
Radialhastighet ()	+17,3 ± 0,2 km/s
Egenrörelse (µ)	RA: +37,037 mas/år; Dek.: -17,714 mas/år
Parallax ()	4,417 ± 0,134
Avstånd	740 ± 20 lå (226 ± 7 pc)
Absolut magnitud ()	+2,94
Detaljer
Massa	1,5 M☉
Radie	390 R☉
Luminositet	5 012 +1 154−938 L☉
Temperatur	2 3902 K
Metallicitet	-0,33 dex
Andra beteckningar
	HD 113285, AG+05 1798, BD+05 2708, DO 3309, GSC 00304-00790, HIC 63642, HIP 63642, IRAS 13001+0527, IRC +10262, 2MASS J13023797+0511083, PPM 159423, RAFGL 1594, SAO 119734, TYC 304-790-1, RT Virginis, Gaia DR3 3705213108816150272, Gaia DR2 3705213108815271680

RT Virginis är en variabel stjärna i stjärnbilden Jungfrun. Dess ljusstyrka varierar från en skenbar magnitud på 7,7 ner till 9,7, vilket är för svagt för att synas för blotta ögat. Baserat på parallaxmätningar gjorda med VLBI är avståndet till stjärnan ca 740 ljusår. Den rör sig från solen med en heliocentrisk radialhastighet på 17 km/s.

Observation

Den långperiodiska variabiliteten hos stjärnan upptäcktes av W.P. Fleming år 1896, baserat på fotografiska plåtar tagna mellan 1886 och 1895. Den listades med sin variabelbeteckning, RT Virginis, i Annie Jump Cannons verk från 1907, Second Catalogue of Variable Stars. A.H. Joy kategoriserade den år 1942 som en oregelbunden variabel stjärna med spektralklass M8 III. År 1969 klassificerades den som en halvregelbunden variabel stjärna av SRb-typen. Perioden bestämdes till 155 dygn av P.N. Kholopov et al. år 1985, och omvärderades sedan till 375 dygn baserat på AAVSO- ljuskurvor år 1997. Den är en syrerik röd jättestjärna på den asymptotiska jättegrenen av sin utveckling och genomgår massförlust på grund av termisk pulsering.

Vattenångemission i närheten av stjärnan observerades i mikrovågsbandet av D.F. Dickinson år 1973. Detta härrör från stark maseremission i ett cirkumstellärt gas-stoftskal. Flödestätheten för dessa vattenmaser är över 100 Jansky. Stjärnan förlorar massa med en hastighet av 3 × 10⁻⁶ solmassa per år, motsvarande en solmassa på 3,3 miljoner år. Hastigheten hos den sfäriskt expanderande gasen är så hög som 11 km/s i vattenmaserområdet, inom en radie av 5 till 25 AE. I en SiO₂-emitterande region belägen ca 400 AE från stjärnan är gashastigheten 7,8 km/s. Detta utflöde verkar klumpigt och asymmetriskt med en stark tidsmässig variation.

Referenser

Den här artikeln är helt eller delvis baserad på material från engelskspråkiga Wikipedia, RT Virginis, 17 december 2025.

Noter

1 2 3 4 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.
1 2 3 4 Zhang, Bo; et al. (November 2017), "VLBA Trigonometric Parallax Measurement of the Semi-regular Variable RT Vir", The Astrophysical Journal, 849 (2): 99, Bibcode:2017ApJ...849...99Z, doi:10.3847/1538-4357/aa8ee9, S2CID 125975009, 99.
1 2 Joy, Alfred H. (November 1942), "A Survey of the Spectra and Radial Velocities of the Less Regular M-Type Variable Stars", Astrophysical Journal, 96: 344, Bibcode:1942ApJ....96..344J, doi:10.1086/144469.
1 2 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, S2CID 119257644.
↑ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
1 2 3 Brand, J.; et al. (December 2020), "Water vapour masers in long-period variable stars. II. The semi-regular variables R Crt and RT Vir", Astronomy and Astrophysics, 644: A45, arXiv:2011.00294, Bibcode:2020A&A...644A..45B, doi:10.1051/0004-6361/202039157, A45.
1 2 Yates, J. A.; et al. (2002), Mineese, Victor; Reid, Mark (eds.), "The H2O maser proper motions of RT Vir and VX Sgr", Cosmic Masers: From Proto-Stars to Black Holes, IAU Symposium, 206, San Francisco: Astronomical Society of the Pacific: 298, Bibcode:2002IAUS..206..298Y.
1 2 3 Imai, H.; et al. (March 1997), "Measurement of shifts in line-of-sight velocities of stellar water masers using VLBI.", Astronomy and Astrophysics, 319: L1 – L4, Bibcode:1997A&A...319L...1I.
1 2 Sharma, Kaushal; et al. (2016), "New atmospheric parameters and spectral interpolator for the MILES cool stars", Astronomy and Astrophysics, 585: A64, arXiv:1512.04882, Bibcode:2016A&A...585A..64S, doi:10.1051/0004-6361/201526111, S2CID 118576178.
↑ https://simbad.cds.unistra.fr/simbad/sim-id?Ident=RT+Vir. Hämtad 2025-12-18.
↑ "RT Vir", SIMBAD, Centre de données astronomiques de Strasbourg, hämtad 2022-09-07
↑ ASAS All Star Catalogue, The All Sky Automated Survey, hämtad 16 September 2022.
↑ Pickering, E. C.; Fleming, W. P. (April 1896), "Harvard College Observatory, circular no. 6. New variable stars", Astrophysical Journal, 3: 296–302, Bibcode:1896ApJ.....3..296P, doi:10.1086/140219.
↑ Cannon, Annie J. (1907). "Second catalogue of variable stars". Annals of Harvard College Observatory. 55: 1–94. Bibcode:1907AnHar..55....1C. Hämtad 16 december 2024.
↑ van der Veen, W. E. C. J.; et al. (March 1995), "The distribution of dust around Asymptotic Giant Branch stars", Astronomy and Astrophysics, 295: 445–458, Bibcode:1995A&A...295..445V.
↑ Dickinson, D. F. (March 1976), "Water emission from infrared stars", Astrophysical Journal Supplement Series, 30: 259–271, Bibcode:1976ApJS...30..259D, doi:10.1086/190362.
1 2 Mendoza-Torres, J. E.; et al. (December 1997), "Evolution of H2O maser emission in the direction of the semiregular variable RT Virginis during 1985-1996", Astronomy and Astrophysics Supplement Series, 126 (2): 257–266, Bibcode:1997A&AS..126..257M, doi:10.1051/aas:1997263.
↑ Sacuto, S.; et al. (March 2013), "The wind of the M-type AGB star RT Virginis probed by VLTI/MIDI", Astronomy and Astrophysics, 551: A72, arXiv:1301.5872, Bibcode:2013A&A...551A..72S, doi:10.1051/0004-6361/201220524, S2CID 18675130, A72.
↑ Yates, J. A.; et al. (2000), Kastner, J. H.; et al. (eds.), "Is the Outflow from RT Vir Bipolar or Rotating?", Asymmetrical Planetary Nebulae II: From Origins to Microstructures, ASP Conference Series, 199: 79, Bibcode:2000ASPC..199...79Y, ISBN 1-58381-026-9.

Vidare läsning

Imai, Hiroshi; Shibata, Katsunori M.; Marvel, Kevin B.; Diamond, Philip J.; Sasao, Tetsuo; Miyoshi, Makoto; Inoue, Makoto; Migenes, Victor; et al. (June 2003), ”The Three-dimensional Kinematics of Water Masers around the Semiregular Variable RT Virginis”, The Astrophysical Journal 590 (1): 460–472, doi:10.1086/374887, Bibcode: 2003ApJ...590..460I.
Etoka, S.; Błaszkiewicz, L.; Szymczak, M.; Le Squeren, A. M. (November 2001), ”Monitoring of long term behaviour of OH masers in semiregular variables: R Crt, W Hya and RT Vir”, Astronomy and Astrophysics 378 (2): 522–538, doi:10.1051/0004-6361:20011184, Bibcode: 2001A&A...378..522E.
Lekht, E. E.; Mendoza-Torres, J. E.; Pashchenko, M. I.; Berulis, I. I. (March 1999), ”Dynamics of the circumstellar envelope of RT Virginis on the basis of the H₂O maser monitoring”, Astronomy and Astrophysics 343: 241–250, Bibcode: 1999A&A...343..241L.
Richards, A. M. S.; Cohen, R. J.; Bains, I.; Yates, J. A. (1999), Le Bertre, T.; Lebre, A.; Waelkens, C., red., ”A MERLIN movie of mass-loss from RT Vir”, Asymptotic Giant Branch Stars, IAU Symposium 191: 315, ISBN 1-886733-90-2, Bibcode: 1999IAUS..191..315R.

[B-1] 1 2 3 4 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.

[C-2] 1 2 3 4 Zhang, Bo; et al. (November 2017), "VLBA Trigonometric Parallax Measurement of the Semi-regular Variable RT Vir", The Astrophysical Journal, 849 (2): 99, Bibcode:2017ApJ...849...99Z, doi:10.3847/1538-4357/aa8ee9, S2CID 125975009, 99.

[E-3] 1 2 Joy, Alfred H. (November 1942), "A Survey of the Spectra and Radial Velocities of the Less Regular M-Type Variable Stars", Astrophysical Journal, 96: 344, Bibcode:1942ApJ....96..344J, doi:10.1086/144469.

[F-4] 1 2 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, S2CID 119257644.

[G-5] Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.

[D-6] 1 2 3 Brand, J.; et al. (December 2020), "Water vapour masers in long-period variable stars. II. The semi-regular variables R Crt and RT Vir", Astronomy and Astrophysics, 644: A45, arXiv:2011.00294, Bibcode:2020A&A...644A..45B, doi:10.1051/0004-6361/202039157, A45.

[H-7] 1 2 Yates, J. A.; et al. (2002), Mineese, Victor; Reid, Mark (eds.), "The H2O maser proper motions of RT Vir and VX Sgr", Cosmic Masers: From Proto-Stars to Black Holes, IAU Symposium, 206, San Francisco: Astronomical Society of the Pacific: 298, Bibcode:2002IAUS..206..298Y.

[I-8] 1 2 3 Imai, H.; et al. (March 1997), "Measurement of shifts in line-of-sight velocities of stellar water masers using VLBI.", Astronomy and Astrophysics, 319: L1 – L4, Bibcode:1997A&A...319L...1I.

[J-9] 1 2 Sharma, Kaushal; et al. (2016), "New atmospheric parameters and spectral interpolator for the MILES cool stars", Astronomy and Astrophysics, 585: A64, arXiv:1512.04882, Bibcode:2016A&A...585A..64S, doi:10.1051/0004-6361/201526111, S2CID 118576178.

[SIMBAD-10] ttps://simbad.cds.unistra.fr/simbad/sim-id?Ident=RT+Vir. Hämtad 2025-12-18.

[K-11] "RT Vir", SIMBAD, Centre de données astronomiques de Strasbourg, hämtad 2022-09-07

[A-12] ASAS All Star Catalogue, The All Sky Automated Survey, hämtad 16 September 2022.

[L-13] Pickering, E. C.; Fleming, W. P. (April 1896), "Harvard College Observatory, circular no. 6. New variable stars", Astrophysical Journal, 3: 296–302, Bibcode:1896ApJ.....3..296P, doi:10.1086/140219.

[M-14] Cannon, Annie J. (1907). "Second catalogue of variable stars". Annals of Harvard College Observatory. 55: 1–94. Bibcode:1907AnHar..55....1C. Hämtad 16 december 2024.

[N-15] van der Veen, W. E. C. J.; et al. (March 1995), "The distribution of dust around Asymptotic Giant Branch stars", Astronomy and Astrophysics, 295: 445–458, Bibcode:1995A&A...295..445V.

[O-16] Dickinson, D. F. (March 1976), "Water emission from infrared stars", Astrophysical Journal Supplement Series, 30: 259–271, Bibcode:1976ApJS...30..259D, doi:10.1086/190362.

[P-17] 1 2 Mendoza-Torres, J. E.; et al. (December 1997), "Evolution of H2O maser emission in the direction of the semiregular variable RT Virginis during 1985-1996", Astronomy and Astrophysics Supplement Series, 126 (2): 257–266, Bibcode:1997A&AS..126..257M, doi:10.1051/aas:1997263.

[Q-18] Sacuto, S.; et al. (March 2013), "The wind of the M-type AGB star RT Virginis probed by VLTI/MIDI", Astronomy and Astrophysics, 551: A72, arXiv:1301.5872, Bibcode:2013A&A...551A..72S, doi:10.1051/0004-6361/201220524, S2CID 18675130, A72.

[R-19] Yates, J. A.; et al. (2000), Kastner, J. H.; et al. (eds.), "Is the Outflow from RT Vir Bipolar or Rotating?", Asymmetrical Planetary Nebulae II: From Origins to Microstructures, ASP Conference Series, 199: 79, Bibcode:2000ASPC..199...79Y, ISBN 1-58381-026-9.