- L170 minutes (18 frames)
- G105 minutes (11 frames)
- R110 minutes (12 frames)
- B90 minutes (9 frames)
Spiral galaxy NGC 2403 is located in the constellation Camellia and has an apparent magnitude of 8.2m. The galaxy is located at a distance of about 10 million light-years from the Sun. It contains blue open star clusters, dark dust lanes, and a relatively small nucleus at the center. Older yellow stars are located closer to the center, and younger blue star-forming regions are located in the spiral arms.
In 2004, one of the brightest supernovae exploded in this galaxy. The galaxy was discovered by William Herschel in 1788. Edwin Hubble discovered Cepheids in NGC 2403 using the Hale telescope, making it the first galaxy outside the Local Group in which a Cepheid was discovered.
Supernovae and Imposters
Four astronomical transients have been detected in the galaxy:
- SN 1954J — initially observed as a bright blue variable star, later classified as an imposter supernova, i.e. a highly luminous, massive star surrounded by a dusty nebula.
- SN 2002kg — discovered in 2002 and classified as a type IIn supernova. In 2021, it was reclassified as a Gap transient.
- SN 2004dj (a type II-P supernova, mag. 11.2) was discovered by Koichi Itagaka in 2004.
- AT 2016ccd — a luminous blue variable star discovered in 2013, with outbursts observed until 2021.
History
The galaxy was discovered by William Herschel in 1788. Edwin Hubble discovered Cepheids in NGC 2403 using the Hale Telescope, making it the first galaxy outside the Local Group to have a Cepheid detected.
Satellites
NGC 2403 has two known satellites:
- DDO 44 is a relatively massive dwarf galaxy that is now being disrupted by NGC 2403.
- MADCASH J074238+652501-dw (MADCASH-1) is a dwarf galaxy similar to typical dwarf spheroidal galaxies in the Local Group.
Bright Blue Variables in NGC 2403
There are four known bright blue variables in the galaxy:
- AT 2016ccd
- NGC 2403 V14
- NGC 2403 V37
- NGC 2403 V12
The galaxy NGC 2403 is the second largest object in the M81 group, after M81 itself. In a broader context, NGC 2403 and the M81 group are part of the Coma-Sculpture Cloud, which includes our Local Group.
Supernovae
- The galaxy has hosted three supernovae in the past 70 years, including one of the brightest in 2004. In 1954, Zwicky noted an event that later turned out to be not a true supernova, but an eruption similar to Eta Carinae in the 19th century.
| Photo | Date | Frames | Exposure | L | R | G | B |
|---|---|---|---|---|---|---|---|
 | 07 Feb 2021 | 50 | 07:55 | 02:50 | 01:50 | 01:45 | 01:30 |
Visibility chart of Spiral Galaxy NGC 2403 during the day
| Date | Moon Phase | Exposure | CCD Temperature | Gain | Offset | Filter |
|---|---|---|---|---|---|---|
- 2023ixf•
- 40 Eri•
- Abell 74•
- Artemis A868 SA•
- a Canis Minoris•
- C 2020 R4 ATLAS•
- C 2020 T2 Palomar•
- C 2021 S3 (PANSTARRS)•
- Haumea (2003 EL61)•
- HCG 68•
- HCG 92•
- IC 1318B•
- IC 1396•
- IC 1795•
- IC 1805•
- IC 1848•
- IC 1871•
- IC 3322A•
- IC 342•
- IC 4015•
- IC 405•
- IC 417•
- IC 434•
- IC 443•
- IC 4703•
- IC 5070•
- IC 5146•
- IC 63•
- M 1•
- M 101•
- M 103•
- M 109•
- M 13•
- M 15•
- M 27•
- M 3•
- M 33•
- M 42•
- M 45•
- M 5•
- M 51•
- M 57•
- M 63•
- M 64•
- M 74•
- M 76•
- M 81•
- M 82•
- M 86•
- M 87•
- M 94•
- M 97•
- NGC 147•
- NGC 1491•
- NGC 1499•
- NGC 1579•
- NGC 1961•
- NGC 2146•
- NGC 2239•
- NGC 2403•
- NGC 281•
- NGC 4236•
- NGC 4565•
- NGC 4631•
- NGC 507•
- NGC 508•
- NGC 5866•
- NGC 5907•
- NGC 6503•
- NGC 6823•
- NGC 6888•
- NGC 6946•
- NGC 6992•
- NGC 6995•
- NGC 7000•
- NGC 7023•
- NGC 7129•
- NGC 7217•
- NGC 7331•
- NGC 7380•
- NGC 7538•
- NGC 7635•
- NGC 7640•
- NGC 7822•
- NGC 891•
- NGC 896•
- NGC 925•
- PGC 54559•
- Sh2-155•
- Sh2-168•
- Sh2 103•
- Sh2 109•
- Sh2 132•
- T CrB•
- UGC 6930•
- V1405 Cas•
- Vesta A807 FA•