NGC 3621

NGC 3621
NGC 3621 taken by the Wide Field Imager (WFI) at ESO's La Silla Observatory
Observation data (J2000 epoch)
ConstellationHydra
Right ascension11h 18m 16.52s[1]
Declination–32° 48′ 50.7″[1]
Redshift0.002435 ± 0.000007[2]
Heliocentric radial velocity+727[3] km/s
Distance21.7 million light years (6.64 Mpc)[4]
Apparent magnitude (V)9.56[5]
Characteristics
TypeSA(s)d[1]
Mass2 × 1010[1] M☉
Apparent size (V)10.96′ × 4.79′[5]
Other designations
UGCA 232, MCG -05-27-008, PGC 34554[5]

NGC 3621 is a field spiral galaxy about 22 Mly (6.7 Mpc) away[4][6] in the equatorial constellation of Hydra. It is comparatively bright and can be well seen in moderate-sized telescopes. The galaxy is around 93,000 ly (29,000 pc) across and is inclined at an angle of 66° from being viewed face on.[7] It shines with a luminosity equal to 13 billion times that of the Sun.[8] The morphological classification is SA(s)d,[1] which indicates this is an ordinary spiral with loosely wound arms.[9] There is no evidence for a bulge.[10] Although it appears to be isolated,[9] NGC 3621 belongs to the Leo spur.[8]

This galaxy has an active nucleus that matches a Seyfert 2 optical spectrum, suggesting that a low mass supermassive black hole is present at the core. Based upon the motion of stars in the nucleus, this object may have a mass of up to three million times the mass of the Sun.[10]

One supernova has been observed in NGC 3621: SN 2024ggi (type II, mag. 18.9).[11] It was discovered on 11 April 2024, and by 16 April it had brightened to magnitude 12. It is the closest supernova to Earth since SN 2023ixf, which was discovered on 19 May 2023.

  1. ^ a b c d e Cite error: The named reference AJ750_2_122 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference APJ128_1_16 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference APJSS96_1_123 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference APJ676_1_184 was invoked but never defined (see the help page).
  5. ^ a b c "NGC 3621". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-24.
  6. ^ Materne, J. (April 1979). "The structure of nearby groups of galaxies - Quantitative membership probabilities". Astronomy and Astrophysics. 74 (2): 235–243. Bibcode:1979A&A....74..235M.
  7. ^ Cite error: The named reference Lang2020 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference OMeara2013 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Buta2007 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference AJ690_1_1031 was invoked but never defined (see the help page).
  11. ^ Transient Name Server entry for SN 2024ggi. Retrieved 12 April 2024.