PU Vulpeculae is a very slowly evolving symbiotic nova in the northern constellation of Vulpecula, abbreviated PU Vul. It is too faint to be visible to the naked eye, reaching a maximum apparent visual magnitude of 8.7 following a minimum of 16.6. The system is located at a distance of approximately 17,000 light years from the Sun based on parallax measurements.
A visual band light curve for PU Vulpeculae, adapted from Belyakina et al.,[1] Kolotilov & Belyakina,[2] and Chochol et al..[3] The main plots show the long-term variability, and the inset plot within the upper panel shows the Mira pulsations. | |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Vulpecula |
Right ascension | 20h 21m 13.311s[4] |
Declination | 21° 34′ 18.70″[4] |
Apparent magnitude (V) | 8.7 to 16.6[5] |
Characteristics | |
Spectral type | M6[6] |
Variable type | Slow nova[5] |
Astrometry | |
Proper motion (μ) | RA: −3.002 mas/yr[4] Dec.: −6.006 mas/yr[4] |
Parallax (π) | 0.1909 ± 0.0393 mas[4] |
Distance | approx. 17,000 ly (approx. 5,000 pc) |
Details | |
Red giant | |
Mass | 0.5–0.9[6] M☉ |
Temperature | 3,200±100[6] K |
White dwarf | |
Mass | 0.6[6] M☉ |
Radius | 0.04[7] – 97[6] R☉ |
Luminosity | 5,900 – 16,800[6] L☉ |
Temperature | 6,300 – 165,000[6] K |
Other designations | |
Database references | |
SIMBAD | data |
The brightening of this object during April 1979 was independently discovered by Y. Kuwano and M. Honda. At detection, it had a visual magnitude of 9.1 and was initially designated Nova Vulpeculae 1979. Photographic plates taken since November 1977 showed a dramatic increase of five magnitudes at the time of discovery. In September, 1978, it had been catalogued as a stellar class of M4.[9] A search of Harvard Observatory archival plates taken since 1898 showed several smaller eruptions of this star.[10]
For much of 1979 the object had a brightness of magnitude 8.9[2] while varying by a magnitude of 0.15 with a period of about 80 says,[11] then it began to fade rapidly in 1980,[12] reaching a minimum magnitude of 13.65 in August. At this minimum, the spectrum showed bands of the TiO molecule, which is typical of lower temperature M-type stars.[1] It began to brighten again at about the same rate as the decrease, reaching magnitude 8.5 in August, 1981.[2] The star remained mostly stable at this level for about a year, displaying a pair of brief dips in brightness during 1982. Polarization of the light indicated the formation of large dust particles, which was suggested as a cause of the brightness decrease in 1980.[1]
A soft X-ray halo was detected around the object in 1980, as well as a weaker ring-like structure.[13] Infrared observations in 1980 suggested this is a symbiotic binary star system consisting of a variable, evolved star that has expanded to fill its Roche lobe and is periodically transferring mass to a faint, compact companion. However, the system did not show the expected emission lines from the infalling material.[14] The spectrum at the minimum indicated the evolved star is a giant of class M6.[1] The hot component showed a supergiant or bright giant spectrum that changed from a class of F5 in 1983 to A2 in 1986,[15] while the brightness remained near magnitude 8.7.[16] During this time the hot component changed from resembling a 97 R☉ supergiant with a temperature similar to the Sun into a white dwarf smaller than the sun with a temperature in excess of 150,000 K.[6] Emission lines became visible in 1988 as the outer layers were shed and became a nebula surrounding the white dwarf remnant.[15]
The brightness of this object finally began to steadily decrease in 1987. By September 1989, it had declined to magnitude 10.5. The spectrum began to resemble a nebula, which came from a hot stellar wind expanding at a velocity of 500 km/s or more. In 1993, the emission features from the wind temporarily disappeared, which suggested the system was undergoing an eclipse. The data indicated this is an eclipsing binary with an orbital period of 13.42±0.27 years, which meant the orbital plane is nearly aligned with the line of sight from the Earth. An eclipse would explain the unusual minimum during 1980.[16] The cool component was determined to be on the asymptotic giant branch and is pulsating with a period of 217 days, making it a Mira variable.[3] The compact companion is a white dwarf with mass estimated at 60% of the mass of the Sun.[6] The system displays an "illumination effect" caused by the ionization of the stellar wind from the giant by the dwarf. The light curve of this variation suggests an orbital eccentricity of at least 0.16.[6]
References
edit- ^ a b c d Belyakina, T. S.; et al. (March 1984), "Kuwano-Honda peculiar object (PU Vul)", Astronomy and Astrophysics, 132: L12–L14, Bibcode:1984A&A...132L..12B.
- ^ a b c Kolotilov, E. A.; Belyakina, T. S. (March 1982), "The Optical Variability of PU Vulpeculae (Kuwano's Object) in 1979-1981", Information Bulletin on Variable Stars, 2097: 1, Bibcode:1982IBVS.2097....1K.
- ^ a b Chochol, D.; et al. (March 1998), "Pulsating AGB star in the symbiotic nova PU Vulpeculae", Information Bulletin on Variable Stars, 4571: 1, Bibcode:1998IBVS.4571....1C.
- ^ a b c d 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 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.
- ^ a b c d e f g h i j Kato, Mariko; et al. (May 2012), "Evolution of the Symbiotic Nova PU Vul—Outbursting White Dwarf, Nebulae, and Pulsating Red Giant Companion", The Astrophysical Journal, 750 (1): 5, arXiv:1202.6171, Bibcode:2012ApJ...750....5K, doi:10.1088/0004-637X/750/1/5, S2CID 119303844, 5.
- ^ Cúneo, Virginia A.; et al. (September 2018), "An illumination effect and an eccentric orbit for the symbiotic binary PU Vul revealed by 32 yr of optical spectroscopy", Monthly Notices of the Royal Astronomical Society, 479 (2): 2728–2742, arXiv:1802.10565, Bibcode:2018MNRAS.479.2728C, doi:10.1093/mnras/sty1686.
- ^ "PU Vul". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2022-08-23.
- ^ Honda, M.; et al. (August 1979), "Observations of a novalike object in Vulpecula", Tokyo Astronomical Bulletin, 262: 2983–2991, Bibcode:1979TokAB.262.2983H.
- ^ Liller, M. H.; Liller, W. (September 1979), "The pre-maximum light curve of the slow Nova Vulpeculae 1979", Astronomical Journal, 84: 1357–1358, Bibcode:1979AJ.....84.1357L, doi:10.1086/112550.
- ^ Kenyon, S. J. (March 1986), "Spectroscopic observations of PU Vulpeculae", Astronomical Journal, 91: 563–569, Bibcode:1986AJ.....91..563K, doi:10.1086/114037.
- ^ Belyakina, T. S.; et al. (February 1982), "Object Kuwano, a novalike (symbiotic?) binary with a red giant: photometry and polarimetry", Soviet Astronomy, 26: 1–3, Bibcode:1982SvA....26....1B.
- ^ Cordova, F. A.; Mason, K. O. (September 1980), "A soft X-ray halo around SU UMa", Nature, 287 (5777): 25–27, Bibcode:1980Natur.287...25C, doi:10.1038/287025a0, S2CID 4322830.
- ^ Bensammar, S.; et al. (March 1980), "Infrared observations of Kuwano's novalike object", Astronomy and Astrophysics, 83: 261–262, Bibcode:1980A&A....83..261B.
- ^ a b Bensammar, S.; et al. (May 1991), "The infrared spectrum of the eruptive star PU Vulpeculae", Astronomy and Astrophysics, 245: 575, Bibcode:1991A&A...245..575B.
- ^ a b Nussbaumer, H.; Vogel, M. (March 1996), "PU Vulpeculae: an eclipsing symbiotic nova", Astronomy and Astrophysics, 307: 470–480, Bibcode:1996A&A...307..470N.
Further reading
edit- Tatarnikova, Anna; et al. (August 2018), "Spectroscopic and photometric observations of symbiotic nova PU Vul during 2009-2016", Research in Astronomy and Astrophysics, 18 (8): 098, arXiv:1803.05739, Bibcode:2018RAA....18...98T, doi:10.1088/1674-4527/18/8/98, S2CID 73653825, 98.
- Shugarov, S.; et al. (2012), "Symbiotic Nova PU Vul -- 33 Years of Observations", Baltic Astronomy, 21 (1–2): 150–156, Bibcode:2012BaltA..21..150S, doi:10.1515/astro-2017-0369, S2CID 133207110.
- Tatarnikova, A. A.; et al. (October 2011), "Spectroscopy and photometry of the symbiotic nova PU Vul during its nebular phase and minimum of 2007", Astronomy Reports, 55 (10): 896–910, Bibcode:2011ARep...55..896T, doi:10.1134/S106377291110009X, S2CID 123575147.
- Kato, Mariko; et al. (February 2011), "A Light-curve Model of the Symbiotic Nova PU Vul (1979): A Very Quiet Explosion with Long-lasting Flat Peak", The Astrophysical Journal, 727 (2): 72, arXiv:1011.5092, Bibcode:2011ApJ...727...72K, doi:10.1088/0004-637X/727/2/72, S2CID 119244386, 72.
- Tatarnikova, A. A.; Tatarnikov, A. M. (November 2009), "Analysis of archive UV observations of the symbiotic nova PU Vul during its nebular stage and brightness minimum in 1993-1994", Astronomy Reports, 53 (11): 1020–1031, Bibcode:2009ARep...53.1020T, doi:10.1134/S1063772909110079, S2CID 121547170.
- Yoo, Kye-Hwa (June 2007), "Nebular Spectrum of PU VUL in 2004", Journal of the Korean Astronomical Society, 40 (2): 39–47, Bibcode:2007JKAS...40...39Y, doi:10.5303/JKAS.2007.40.2.039.
- Garnavich, Peter M. (1996), "The Period of the Symbiotic Nova Pu Vulpeculae", The Journal of the American Association of Variable Star Observers, 24 (2): 81–85, Bibcode:1996JAVSO..24...81G.
- Andrillat, Yvette; Houziaux, Leo (September 1995), "PU Vul during the Brightness Weakening of 1993-1994", Information Bulletin on Variable Stars, 4251: 1, Bibcode:1995IBVS.4251....1A.
- Kolotilov, E. A.; et al. (July 1995), "On the new minimum of the symbiotic nova PU Vulpeculae", Monthly Notices of the Royal Astronomical Society, 275 (1): 185–190, Bibcode:1995MNRAS.275..185K, doi:10.1093/mnras/275.1.185.
- Klein, A.; et al. (April 1994), "The development of the symbiotic nova PU Vulpeculae in the years 1984-1992", Astronomy and Astrophysics Supplement, 104: 99–114, Bibcode:1994A&AS..104...99K.
- Andrillat, Y.; Houziaux, L. (December 1994), "Spectroscopic observations of PU Vulpeculae in the 3210-10950 A range during the nebular phase", Monthly Notices of the Royal Astronomical Society, 271 (4): 875–898, Bibcode:1994MNRAS.271..875A, doi:10.1093/mnras/271.4.875.
- Sion, Edward M. (July 1993), "On a Thermonuclear Origin for the 1980-81 Deep Light Minimum of the Symbiotic Nova PU VUL", Astronomical Journal, 106: 298, Bibcode:1993AJ....106..298S, doi:10.1086/116637.
- Sion, Edward M.; et al. (November 1993), "The Onset of Wolf-Rayet Wind Outflow and the Nature of the Hot Component in the Symbiotic Nova PU Vulpecula", Astronomical Journal, 106: 2118, Bibcode:1993AJ....106.2118S, doi:10.1086/116789.
- Tamura, Shin-Ichi; et al. (October 1992), "Abrupt Change of the Hα Emission-Line Profile of PU Vulpeculae in 1989", Publications of the Astronomical Society of Japan, 44: 543–551, Bibcode:1992PASJ...44..543T.
- Gochermann, J. (October 1991), "PU Vulpeculae at the time of spectral change in 1987", Astronomy and Astrophysics, 250: 361, Bibcode:1991A&A...250..361G.
- Tomov, T.; et al. (September 1991), "Wolf-Rayet features observed in the spectrum of the symbiotic nova PU Vulpeculae", Monthly Notices of the Royal Astronomical Society, 252: 31p–35p, Bibcode:1991MNRAS.252P..31T, doi:10.1093/mnras/252.1.31P.
- Kanamitsu, Osamu; et al. (June 1991), "Weak-Line to Emission-Line Phases of PU Vulpeculae", Publications of the Astronomical Society of Japan, 43: 523–545, Bibcode:1991PASJ...43..523K.
- Kanamitsu, Osamu (April 1991), "A Spectroscopic Study of PU Vulpeculae", Publications of the Astronomical Society of Japan, 43: 225–259, Bibcode:1991PASJ...43..225K.
- Belyakina, T. S.; et al. (October 1989), "The Kuwano-Honda's peculiar object (PU Vulpeculae) in 1983-1986", Astronomy and Astrophysics, 223: 119–135, Bibcode:1989A&A...223..119B.
- Iijima, T. (May 1989), "Recent spectral variation of the peculiar nova-like object PU Vulpeculae", Astronomy and Astrophysics, 215: 57–62, Bibcode:1989A&A...215...57I.
- Chochol, D.; Grygar, J. (March 1987), "Extremely slow nova PU Vulpeculae — Seven fat years after maximum", Astrophysics and Space Science, 131 (1–2): 487–491, Bibcode:1987Ap&SS.131..487C, doi:10.1007/BF00668131, S2CID 189848087.
- Chochol, D.; Grygar, J. (January 1986), "Peculiar Slow Nova-like Object PU VUL - Facts and Interpretation", Communications of the Konkoly Observatory, vol. 86, p. 355, Bibcode:1986CoKon..86..355C.
- Friedjung, M.; et al. (December 1984), "New results on PU Vul", NASA. Goddard Space Flight Center Future of Ultraviolet Astronomy Based on Six Years of IUE Res, vol. 2349, pp. 305–308, Bibcode:1984NASCP2349..305F.
- Iijima, T.; Ortolani, S. (July 1984), "Spectral variation and the expanding envelope of PU Vulpeculae", Astronomy and Astrophysics, 136: 1–9, Bibcode:1984A&A...136....1I.
- Purgathofer, A.; Schnell, A. (January 1983), "Photoelectric UBV Observations of PU Vul in 1982", Information Bulletin on Variable Stars, 2264: 1, Bibcode:1983IBVS.2264....1P.
- Yamashita, Y.; et al. (1983), "Spectral change of PU Vulpeculae (nova VUL 1979)", Publications of the Astronomical Society of Japan, 35: 521–529, Bibcode:1983PASJ...35..521Y.
- Gershberg, R. E.; et al. (February 1982), "Objet Kuwano, a novalike (symbiotic?) binary with a red giant: spectroscopy", Soviet Astronomy, 26: 3–9, Bibcode:1982SvA....26....3G.
- Yamashita, Y.; et al. (1982), "Spectroscopic observations of PU Vulpeculae (Nova Vul 1979)", Publications of the Astronomical Society of Japan, 34: 269–280, Bibcode:1982PASJ...34..269Y.
- Chochol, D.; et al. (December 1981), "PU Vulpeculae (object Honda-Kuwano 1979) - 78.1 Days Period", Information Bulletin on Variable Stars, 2059: 1, Bibcode:1981IBVS.2059....1C.