TT Cygni

TT Cygni
Observation data; Epoch J2000.0 Equinox J2000.0
Constellation	Cygnus
Right ascension	19h 40m 57.01599s[1]
Declination	+32° 37′ 05.7555″[1]
Apparent magnitude (V)	7.26 - 8.0[2]
Characteristics
Evolutionary stage	AGB
Spectral type	C5,4e(N3e)[2]
B−V color index	+2.917±0.073[3]
Variable type	SRb[4]
Astrometry
Radial velocity (Rv)	−49.0±3.1[3] km/s
Proper motion (μ)	RA: −5.178[1] mas/yr ; Dec.: −1.832[1] mas/yr
Parallax (π)	1.4908 ± 0.0368[1] mas
Distance	2,190 ± 50 ly ; (670 ± 20 pc)
Absolute magnitude (MV)	−1.297 (var.)[5]
Details
Radius	166[6] R☉
Luminosity	2,735[7] L☉
Surface gravity (log g)	−0.4[7] cgs
Temperature	3,200[7] K
Other designations
	TT Cyg, BD+32°3522, HD 186047, HIP 96836, SAO 68688[8]
Database references
SIMBAD	data

TT Cygni is a carbon star located 561 parsecs (1,830 ly) away in the northern constellation of Cygnus. It is classified as a semiregular variable of subtype SRb that ranges in brightness from magnitude 7.26 down to 8.0 with a period of 118 days.[2] This object is called a carbon star because it has a high ratio of carbon to oxygen in its surface layers. The carbon was produced by helium fusion, dredged up from inside the star by deep convection triggered by a flash from the helium shell.

A thin spherical shell around the star, about half a light year across, was emitted 7,000 years ago.[9] It was first detected from its carbon monoxide emission and has a mass around four thousandths M_☉, of which about a tenth is dust. The dust is thought to be mostly amorphous carbon.[7]

References

Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
"TT Cygni", International Variable Star Index, AAVSO, retrieved 2021-02-04.
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.
Gontcharov, G. A. (2011), "The red giant branch in the Tycho-2 catalogue", Astronomy Letters, 37 (10): 707–717, arXiv:1607.00557, Bibcode:2011AstL...37..707G, doi:10.1134/S1063773711090040, S2CID 119272127.
McDonald, I.; Zijlstra, A. A.; Watson, R. A. (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.
Groenewegen, M. A. T. (2012), "An extension of the DUSTY radiative transfer code and an application to OH 26.5 and TT Cygni", Astronomy and Astrophysics, 543: A36, Bibcode:2012A&A...543A..36G, doi:10.1051/0004-6361/201218965.
"TT Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-03.
Olofsson, H.; et al. (January 2000), "A high-resolution study of episodic mass loss from the carbon star TT Cygni", Astronomy and Astrophysics, 353: 583–597, Bibcode:2000A&A...353..583O.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.

[GaiaDR2-1] Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.

[vsx-2] "TT Cygni", International Variable Star Index, AAVSO, retrieved 2021-02-04.

[Anderson_Francis_2012-3] 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, S2CID 119257644.

[Samus_et_al_2017-4] 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.

[gontcharov2011-5] Gontcharov, G. A. (2011), "The red giant branch in the Tycho-2 catalogue", Astronomy Letters, 37 (10): 707–717, arXiv:1607.00557, Bibcode:2011AstL...37..707G, doi:10.1134/S1063773711090040, S2CID 119272127.

[mcdonald2017-6] McDonald, I.; Zijlstra, A. A.; Watson, R. A. (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.

[groenewegen2012-7] Groenewegen, M. A. T. (2012), "An extension of the DUSTY radiative transfer code and an application to OH 26.5 and TT Cygni", Astronomy and Astrophysics, 543: A36, Bibcode:2012A&A...543A..36G, doi:10.1051/0004-6361/201218965.

[SIMBAD-8] "TT Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-03.

[Olofsson_et_al_2000-9] Olofsson, H.; et al. (January 2000), "A high-resolution study of episodic mass loss from the carbon star TT Cygni", Astronomy and Astrophysics, 353: 583–597, Bibcode:2000A&A...353..583O.