SN 2019np

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SN 2019np
Event typeSupernova
Type Ia[1]
ConstellationLeo Minor
Right ascension10h 29m 21.980s[2]
Declination+29° 30′ 38.30″[2]
EpochJ2000
Distance107.0 ± 22.2 Mly (32.80 ± 6.8 Mpc)[3]
Redshift0.00452[2]
HostNGC 3254[2]
Colour (B-V)−0.06±0.03[3]
Peak apparent magnitude13.62±0.15[3]

SN 2019np was a Type Ia supernova[1] event in NGC 3254, which is an unbarred spiral galaxy in the northern Constellation of Leo Minor. Based on the Tully–Fisher relation, this galaxy is located at a distance of 107.0 ± 22.2 million light-years (32.80 ± 6.8 Mpc) from the Milky Way.[3] This supernova was discovered January 9, 2019 by Kōichi Itagaki,[2] and reached maximum two weeks later.[4] It was the brightest supernova observed in the year 2019.[5]

Observations

This supernova was discovered by Japanese amateur astronomer Kōichi Itagaki on January 9, 2019, using a 0.35-m telescope.[2] The early spectrum was consistent with a Type Ia supernova.[1][6] On January 11, it was measured at an apparent visual magnitude of 16.68 with an estimated two weeks until maximum.[4] It reached visual magnitude 13.6 at maximum.[3]

The spectral evolution of SN 2019np followed the normal pattern for a Type Ia supernova. The velocity of the ejecta was around 10,200 km/s at maximum, as measured from ionized silicon. Early observations showed an infrared excess, which may be explained by a collision between the ejecta and a companion star. The data is best explained by a solar mass companion on the main sequence.[3]

The explosion data is most consistent with a carbon-oxygen white dwarf that evolved from a star with five times the mass of the Sun. This compact object accreted matter from its companion until its mass approached the Chandrasekhar limit, when it detonated.[7] The explosion generated an estimated 0.66±0.05 M☉ of synthesized nickel.[3]

References

  1. Wu, Chengyuan; et al. (January 2019), "Spectroscopic Classification of AT 2019np as a Young Type Ia Supernova", The Astronomer's Telegram, 12374, Bibcode:2019ATel12374....1W.
  2. "SN 2019np", Transient Name Server, IAU Supernova Working Group, retrieved 2026-03-21.
  3. Sai, Hanna; et al. (August 2022), "Observations of the very young Type Ia Supernova 2019np with early-excess emission", Monthly Notices of the Royal Astronomical Society, 514 (3): 3541–3558, arXiv:2205.15596, Bibcode:2022MNRAS.514.3541S, doi:10.1093/mnras/stac1525.
  4. Konyves-Toth, R.; et al. (January 2019), "BVRI Photometry of the Young Type Ia SN 2019np", The Astronomer's Telegram, 12378, Bibcode:2019ATel12378....1K.
  5. Bishop, David, "Bright Supernovae - 2019", Rochester Astronomy, retrieved 2024-12-09.
  6. Kilpatrick, C. D.; Foley, R. J. (January 2019), "Spectroscopic Classification of AT2019np with Faulkes-North/FLOYDS", The Astronomer's Telegram, 12375, Bibcode:2019ATel12375....1K.
  7. Hoeflich, Peter; et al. (March 2023), "The core normal Type Ia supernova 2019np - an overall spherical explosion with an aspherical surface layer and an aspherical 56Ni core", Monthly Notices of the Royal Astronomical Society, 520 (1): 560–582, arXiv:2301.04721, Bibcode:2023MNRAS.520..560H, doi:10.1093/mnras/stad172.

Further reading

  • Perez-Torres, M.; et al. (January 2019), "Radio constraints on the mass-loss rate of the Type Ia SN 2019np", The Astronomer's Telegram, 12411, Bibcode:2019ATel12411....1P.
  • Konyves-Toth, R.; et al. (January 2019), "BVRI Photometry of the Young Type Ia SN 2019np", The Astronomer's Telegram, 12378, Bibcode:2019ATel12378....1K.