Nova Cassiopeiae 2021

Summary

Nova Cassiopeiae 2021, also known V1405 Cassiopeiae, was a nova in the constellation Cassiopeia. It reached a peak brightness of magnitude 5.449 on May 9, 2021, making it visible to the naked eye.[4] It was discovered by Japanese amateur astronomer Yuji Nakamura of Kameyama, Japan, at 10:10 UT on March 18, 2021. The nova was first seen by Nakamura in four 15 second CCD exposures with a 135mm F/4 lens, when it was at magnitude 9.3. Nothing was seen brighter than magnitude 13.0 with the same equipment in exposures taken at 10:12 UT on March 14, 2021.[4][5][6] For the first seven months after discovery, the nova's brightness stayed at a rough plateau, fading and rebrightening at least eight times; it is considered a very slow nova.[7] After the seven month long series of peaks, Nova Cassiopeiae began a linear decline in brightness.[4] This nova has been detected throughout the electromagnetic spectrum, from radio to gamma rays.[8][9]

Nova Cassiopeiae 2021

A visual band light curve for Nova Cassiopeiae 2021, plotted from AAVSO data.[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cassiopeia
Right ascension 23h 24m 47.73165s[2]
Declination +61° 11′ 14.7951″[2]
Apparent magnitude (V) 5.2 - 15.6[3]
Astrometry
Proper motion (μ) RA: −0.912±0.026[2] mas/yr
Dec.: −1.319±0.026[2] mas/yr
Parallax (π)0.5776 ± 0.0254 mas[2]
Distance5,600 ± 200 ly
(1,730 ± 80 pc)
Characteristics
Variable type Nova
Other designations
V1405 Cas, 2MASS J23244772+6111149, PNV J23244760+6111140
Database references
SIMBADdata

All novae are binary stars, consisting of a white dwarf orbiting a "donor star" from which the white dwarf accretes material. Spectra taken of Nova Cassiopeiae around maximum brightness showed that the nova was an FE II type novae.[10] The ejecta from FE II novae is believed to come from a large circumbinary envelope of gas (which was lost from the donor star), rather than the white dwarf.[11] TESS observations revealed an orbital period of 4.52138±0.00012 hours for the binary system.[12]

References edit

  1. ^ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
  2. ^ a b c d e 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.
  3. ^ "V1405 Cas". The International Variable Star Index. AAVSO. Retrieved 12 June 2022.
  4. ^ a b c Munari, U.; Valisa, P.; Dallaporta, S.; Maitan, A. (December 2021). "High ionization conditions finally emerge as Nova Cas 2021 (V1405 Cas) ends the plateau and embraces a steady decline". The Astronomer's Telegram. 15093: 1. Bibcode:2021ATel15093....1M. Retrieved 11 June 2022.
  5. ^ "CBAT "Transient Object Followup Reports"". Central Bureau for Astronomical Telegrams. Harvard University. Retrieved 11 June 2022.
  6. ^ Maehara, Hiroyuki; Taguchi, Kenta; Tampo, Yusuke; Kojiguchi, Naoto; Isogai, Keisuke (March 2021). "Spectroscopic classification of PNV J23244760+6111140 as a classical nova". The Astronomer's Telegram. 14471: 1. Bibcode:2021ATel14471....1M. Retrieved 11 June 2022.
  7. ^ Gehrz, R. D.; Banerjee, D. P. K.; Evans, A.; Karnath, N.; Starrfield, S.; Vacca, W. D.; Wagner, R. M.; Woodward, C. E. (July 2021). "The Mid-IR SOFIA FORCAST Spectrum of Nova V1405 Cassiopeia". The Astronomer's Telegram. 14794: 1. Bibcode:2021ATel14794....1G. Retrieved 11 June 2022.
  8. ^ Sokolovsky, Kirill; Aydi, Elias; Chomiuk, Laura; Kawash, Adam; Strader, Jay; Babul, Aliya-Nur; Sokoloski, Jennifer; Linford, Justin; Mukai, Koji; Li, Kwan-Lok (June 2021). "VLA radio detection of Galactic novae V1674 Her and V1405 Cas". The Astronomer's Telegram. 14731: 1. Bibcode:2021ATel14731....1S.
  9. ^ Li, Kwan-Lok (June 2021). "Fermi-LAT Detection of TCP J18573095+1653396 (=Nova Her 2021)". The Astronomer's Telegram. 14705: 1. Bibcode:2021ATel14705....1L. Retrieved 11 June 2022.
  10. ^ Munari, U.; Valisa, P.; Dallaporta, S. (May 2021). "Large brightness increase of V1405 Cas (Nova Cas 2021) to naked-eye visibility". The Astronomer's Telegram. 14614: 1. Bibcode:2021ATel14614....1M. Retrieved 11 June 2022.
  11. ^ Williams, Robert (October 2012). "Origin of the 'He/N' and 'Fe II' Spectral Classes of Novae". The Astronomical Journal. 144 (4): 98. arXiv:1208.0380. Bibcode:2012AJ....144...98W. doi:10.1088/0004-6256/144/4/98. S2CID 118481768.
  12. ^ Schaefer, Bradley E. (2021). "Discovery of 13 New Orbital Periods for Classical Novae". Research Notes of the American Astronomical Society. 5 (6): 150. arXiv:2106.13907. Bibcode:2021RNAAS...5..150S. doi:10.3847/2515-5172/ac0d5b. S2CID 235632263.