NGC 646 explained

NGC 646
Appmag B:15.65
Sbrightness:22.53 mag/arcsec2
Epoch:J2000
Type:SAB(s)c pec?
Constellation Name:Hydrus
Names:PGC 6010
Dist Ly:392 Mly

NGC 646 is a large barred spiral galaxy located in the constellation Hydrus.[1] Its speed relative to the cosmic microwave background is 8,145 ± 19 km/s, which corresponds to a Hubble distance of 120.1 ± 8.4 Mpc (~392 million ly). NGC 646 was discovered by British astronomer John Herschel in 1834.[2] It forms an interacting galaxy pair.[3]

Luminosity

The luminosity class of NGC 646 is III.[4] It has surface brightness equal to 14.69 mag/am2.[5] NGC 646 is a low surface brightness galaxy (LSB). LSB galaxies are diffuse (D) galaxies with a surface brightness less than one magnitude lower than that of the ambient night sky.

Distance

The Hubble distance of PGC 6014, the galaxy to the east of NGC 646, is 106.4 ± 7.5 Mpc (~347 million ly).[6] A distance of approximately 45 million light years therefore separates these two galaxies which appear to be neighbors in the image. Their gravitational interaction, if there is any interaction, should therefore be of short duration.[7]

See also

External links

Notes and References

  1. Web site: NGC 646 NED02 - Elliptical/Spiral Galaxy in Hydrus TheSkyLive.com . 2024-04-15 . theskylive.com.
  2. Web site: New General Catalog Objects: NGC 600 - 649 . 2024-04-18 . cseligman.com.
  3. Danziger . I. J. . Schuster . H. -E. . 1974-08-01 . The interacting galaxy system NGC 646. . Astronomy and Astrophysics . 34 . 301–303 . 1974A&A....34..301D . 0004-6361.
  4. Web site: Your NED Search Results . 2024-04-18 . ned.ipac.caltech.edu.
  5. Web site: http://astrovalleyfield.ca/AstronomieCompl/NGC%20et%20autres/WolfgangS/N0600_exc_web.htm . 2024-05-03 . astrovalleyfield.ca.
  6. Web site: Your NED Search Results . 2024-04-18 . ned.ipac.caltech.edu.
  7. Web site: New General Catalog Objects: NGC 600 - 649 . 2024-04-18 . cseligman.com.