Astronomy:IRAS 19475+3119
 IRAS 19474+3119 | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 49m 29.5618s[1] |
| Declination | +31° 27′ 16.249″[1] |
| Apparent magnitude (V) | 9.33 - 9.50[2] |
| Characteristics | |
| Evolutionary stage | Protoplanetary nebula |
| Spectral type | F3 Ibe[3] |
| Variable type | SRd[2] |
| Astrometry | |
| Proper motion (μ) | RA: −0.156[1] mas/yr Dec.: −1.684[1] mas/yr |
| Parallax (π) | 0.3159 ± 0.0209[1] mas |
| Distance | 4,900[4] pc |
| Details | |
| Mass | 0.63[4] M☉ |
| Radius | 58[4] R☉ |
| Luminosity | 8,300[4] L☉ |
| Surface gravity (log g) | 0.5[4] cgs |
| Temperature | 7,200[3] K |
| Metallicity [Fe/H] | −0.25[3] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
IRAS 19475+3119 is a protoplanetary nebula in the constellation of Cygnus, 15,000 light-years away. The central star, V2513 Cygni, is an F-type post-AGB star.
The brightest portion of the nebula shows a quadrupolar structure, with elongated bipolar lobes, all surrounded by a faint halo.[5]
The distance is essentially unknown. Assumptions about the luminosity have been used to estimate the distance and other stellar parameters. At an assumed kinematical distance of 4.9 kpc, the luminosity is 8,300 L☉ and the radius 58 R☉.[4] The star was originally at least 2.5 M☉ and is now 0.63 M☉.[5] Assuming a luminosity of 3,500 L☉, the distance becomes 1.5 kpc.[7] Estimates based on the oxygen spectral line strengths give much higher values luminosities with an absolute magnitude of at least −8.[3]
The central star is variable, from about magnitude 9.33 to 9.50. A primary period of 41 days has been determined, but a slightly shorter secondary period leads to long beats causing variations in the amplitude and apparent period from year to year. The variations are caused by stellar pulsations, with the star being brightest when it is hottest. The temperature varies by up to 400 K.[8]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 2.0 2.1 Samus, N. N. et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1. Bibcode: 2009yCat....102025S.
- ↑ 3.0 3.1 3.2 3.3 Klochkova, V. G.; Panchuk, V. E.; Tavolzhanskaya, N. S. (2002). "HD 331319: A Post-AGB F Supergiant with He I Lines". Astronomy Letters 28 (1): 49–62. doi:10.1134/1.1434453. Bibcode: 2002AstL...28...49K.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Hsu, Ming-Chien; Lee, Chin-Fei (2011). "An Envelope Disrupted by a Quadrupolar Outflow in the Pre-planetary Nebula IRAS 19475+3119". The Astrophysical Journal 736 (1): 30. doi:10.1088/0004-637X/736/1/30. Bibcode: 2011ApJ...736...30H.
- ↑ 5.0 5.1 Sahai, Raghvendra; Sánchez Contreras, Carmen; Morris, Mark; Claussen, Mark (2007). "A Quadrupolar Preplanetary Nebula: IRAS 19475+3119". The Astrophysical Journal 658 (1): 410–422. doi:10.1086/511294. Bibcode: 2007ApJ...658..410S.
- ↑ Hrivnak, Bruce J.; Van de Steene, Griet; Van Winckel, Hans; Lu, Wenxian; Sperauskas, Julius (December 2018). "Variability in Proto-planetary Nebulae. V. Velocity and Light Curve Analysis of IRAS 17436+5003, 18095+2704, and 19475+3119". The Astronomical Journal 156 (6): 300. doi:10.3847/1538-3881/aaee69. Bibcode: 2018AJ....156..300H.
- ↑ Vickers, Shane B.; Frew, David J.; Parker, Quentin A.; Bojičić, Ivan S. (2015). "New light on Galactic post-asymptotic giant branch stars - I. First distance catalogue". Monthly Notices of the Royal Astronomical Society 447 (2): 1673. doi:10.1093/mnras/stu2383. Bibcode: 2015MNRAS.447.1673V.
- ↑ Hrivnak, Bruce J.; Lu, Wenxian; Nault, Kristie A. (2015). "Variability in Proto-planetary Nebulae. IV. Light Curve Analysis of Four Oxygen-rich, F Spectral Type Objects". The Astronomical Journal 149 (6): 184. doi:10.1088/0004-6256/149/6/184. Bibcode: 2015AJ....149..184H.
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