V392 Persei

V392 Persei
	Location of V392 Persei (circled)
Observation data; Epoch J2000.0 Equinox J2000.0
Constellation	Perseus
Right ascension	04h 43m 21.37s
Declination	+47° 21′ 25.9″
Apparent magnitude (V)	6.3 - 16.9
Characteristics
B−V color index	+1.0
V−R color index	+0.9
Variable type	dwarf nova & nova
Astrometry
Proper motion (μ)	RA: 0.193 mas/yr ; Dec.: −1.749 mas/yr
Parallax (π)	0.2573 ± 0.0516 mas
Distance	4161+2345; −440 pc
Absolute magnitude (MV)	−10.1 (max)
Other designations
	AAVSO 0435+47, V392 Per, Gaia DR2 254361745823908736, 2MASS J04432138+4721257
Database references
SIMBAD	data

V392 Persei, also known as Nova Persei 2018, is a bright nova in the constellation Perseus discovered on April 29, 2018. It was previously known as a dwarf nova.

Dwarf nova

A U Geminorum-type variable star or dwarf nova is a type of cataclysmic variable star consisting of a close binary star system in which one of the components is a white dwarf that accretes matter from a cool main sequence or subgiant companion.^[8] V392 Persei was discovered in 1970 and received its variable star designation a year later. It is normally visual magnitude 17.4 and experiences outbursts of 2-3 magnitudes.^[1] Its spectrum in the quiescent state has been studied and only the cool star is detected. The spectrum shows emission lines of hydrogen-alpha (Hα) and both neutral and ionised helium.^[3] The brightest recorded observations is at magnitude 5.6.^[6]

Nova eruption

On April 29, 2018 it was discovered by Yuji Nakamura to be extremely bright, and it was spectroscopically confirmed as a nova outburst with magnitude 6.2 on April 30. The spectrum includes broad Hα and FeII emission lines with P Cygni profiles. The absorption core is blueshifted by a velocity of 2,680 km/s, which would be the expansion velocity from the nova explosion.^[9]

Observations with Fermi-LAT on April 30 show a strong gamma-ray source at the coordinates of the nova.^[10] Photometry of the nova from Konkoly Observatory on May 1, 2018 give apparent magnitudes of 7.38 in the V band and 8.22 in the B band, suggesting it is already declining.^[11]

System

V392 Persei is the southern of a pair of stars separated by 8.5".^[2]

The symbiotic pair are unresolved, with an orbital period of only 3.21997 days,^[12] and the nature of the cool component is unclear. The spectral energy distribution is inconsistent with a bright giant star but it could be less luminous red clump giant or subgiant. If the cool component was a main sequence red dwarf as expected for a dwarf nova, then the system would need to be closer than the 13,000 ly suggested by its Gaia parallax.^[6]

Gallery

Dwarf nova V392 Persei over the ESO Supernova Planetarium & Visitor Centre.^[13]
V392 Persei, 2 May 2018, 22:00 UT. The slightly fainter nearby star is 9th magnitude BD+47°1026. Up is approximately east.

References

^ ^a ^b ^c ^d Samus, N. N.; Durlevich, O. V.; 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.
^ ^a ^b Watson, C. L. (2006). "The International Variable Star Index (VSX)". The Society for Astronomical Sciences 25th Annual Symposium on Telescope Science. Held May 23–25. 25: 47. Bibcode:2006SASS...25...47W.
^ ^a ^b ^c Liu, Wu; Hu, J. Y (2000). "Spectroscopic Confirmation of Northern and Equatorial Cataclysmic Variables. III. 32 Poorly Known Objects". The Astrophysical Journal Supplement Series. 128 (1): 387–401. Bibcode:2000ApJS..128..387L. doi:10.1086/313380.
^ ^a ^b ^c 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.
^ Schaefer, Bradley E. (2018). "The distances to Novae as seen by Gaia". Monthly Notices of the Royal Astronomical Society. 481 (3): 3033–3051. arXiv:1809.00180. Bibcode:2018MNRAS.481.3033S. doi:10.1093/mnras/sty2388. S2CID 118925493.
^ ^a ^b ^c Darnley, M. J; Starrfield, S (2018). "On the Progenitor System of V392 Persei". Research Notes of the AAS. 2 (2): 24. arXiv:1805.00994. Bibcode:2018RNAAS...2...24D. doi:10.3847/2515-5172/aac26c. S2CID 119486187.
^ "V392 Per". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-25.
^ N.N. Samus; O.V. Durlevich (February 12, 2009). "GCVS Variability Types and Distribution Statistics of Designated Variable Stars According to their Types of Variability". Retrieved 2013-02-08.
^ R. M. Wagner; D. Terndrup; M. J. Darnley; S. Starrfield; C. E. Woodward; M. Henze. "Optical Spectroscopy of TCP J04432130+4721280 (V392 Per) Confirms a Nova Eruption". Retrieved 2018-05-02.
^ Kwan-Lok Li; Laura Chomiuk; Jay Strader. "Bright gamma-ray emission from TCP J04432130+4721280 (V392 Per) detected by Fermi-LAT". Retrieved 2018-05-02.
^ R. Konyves-Toth; B. Csak; A. Pal; J. Vinko. "Optical Photometry of the Nova Outburst TCP J04432130+4721280 (V392 Per)". Retrieved 2018-05-02.
^ Schaefer, Bradley E. (2021). "Discovery of 13 New Orbital Periods for Classical Novae". Research Notes of the AAS. 5 (6): 150. arXiv:2106.13907. Bibcode:2021RNAAS...5..150S. doi:10.3847/2515-5172/ac0d5b. S2CID 235632263.
^ "Nova over Supernova". www.eso.org. Retrieved 7 May 2018.

External links

Dwarf Nova V392 Persei Goes Big — It’s Now Binocular Bright
How A Dwarf Nova Hit The Big Time May 2, 2018
Nova in Perseus
V392 Per in outburst, showing spectra of the nova in outburst and previously

[gcvs-1] Samus, N. N.; Durlevich, O. V.; 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.

[vsx-2] Watson, C. L. (2006). "The International Variable Star Index (VSX)". The Society for Astronomical Sciences 25th Annual Symposium on Telescope Science. Held May 23–25. 25: 47. Bibcode:2006SASS...25...47W.

[liu-3] Liu, Wu; Hu, J. Y (2000). "Spectroscopic Confirmation of Northern and Equatorial Cataclysmic Variables. III. 32 Poorly Known Objects". The Astrophysical Journal Supplement Series. 128 (1): 387–401. Bibcode:2000ApJS..128..387L. doi:10.1086/313380.

[dr2-4] 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.

[Schaefer2018-5] Schaefer, Bradley E. (2018). "The distances to Novae as seen by Gaia". Monthly Notices of the Royal Astronomical Society. 481 (3): 3033–3051. arXiv:1809.00180. Bibcode:2018MNRAS.481.3033S. doi:10.1093/mnras/sty2388. S2CID 118925493.

[darnley-6] Darnley, M. J; Starrfield, S (2018). "On the Progenitor System of V392 Persei". Research Notes of the AAS. 2 (2): 24. arXiv:1805.00994. Bibcode:2018RNAAS...2...24D. doi:10.3847/2515-5172/aac26c. S2CID 119486187.

[Simbad-7] "V392 Per". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-25.

[GCVS-8] N.N. Samus; O.V. Durlevich (February 12, 2009). "GCVS Variability Types and Distribution Statistics of Designated Variable Stars According to their Types of Variability". Retrieved 2013-02-08.

[telegram-9] R. M. Wagner; D. Terndrup; M. J. Darnley; S. Starrfield; C. E. Woodward; M. Henze. "Optical Spectroscopy of TCP J04432130+4721280 (V392 Per) Confirms a Nova Eruption". Retrieved 2018-05-02.

[fermilat-10] Kwan-Lok Li; Laura Chomiuk; Jay Strader. "Bright gamma-ray emission from TCP J04432130+4721280 (V392 Per) detected by Fermi-LAT". Retrieved 2018-05-02.

[konkoly-11] R. Konyves-Toth; B. Csak; A. Pal; J. Vinko. "Optical Photometry of the Nova Outburst TCP J04432130+4721280 (V392 Per)". Retrieved 2018-05-02.

[Schaefer-12] Schaefer, Bradley E. (2021). "Discovery of 13 New Orbital Periods for Classical Novae". Research Notes of the AAS. 5 (6): 150. arXiv:2106.13907. Bibcode:2021RNAAS...5..150S. doi:10.3847/2515-5172/ac0d5b. S2CID 235632263.

[13] "Nova over Supernova". www.eso.org. Retrieved 7 May 2018.

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