NGC 6503

NGC 6503
HST image of NGC 6503's spiral arms[1]
Observation data (J2000 epoch)
ConstellationDraco
Right ascension17h 49m 26.4207s[2]
Declination+70° 08′ 39.587″[2]
Redshift0.000143[3]
Heliocentric radial velocity28[4] km/s
Distance20.9 ± 2.2 Mly (6.40 ± 0.66 Mpc)[4]
Apparent magnitude (V)10.2[5]
Characteristics
TypeSAB:(s)bc[6]
Apparent size (V)7.1′ × 2.4′[7]
Other designations
IRAS 17499+7009, 2MASX J17492651+7008396, UGC 11012, LEDA 60921, MCG +12-17-009[3]

NGC 6503 is a field[8] dwarf spiral galaxy in the northern constellation of Draco. It was discovered by German astronomer Arthur von Auwers on July 22, 1854.[5] The galaxy has an angular size of 7.1′ × 2.4′[7] and an apparent visual magnitude of 10.2.[5] It is located at a distance of approximately 20.9 million light-years (6.40 Mpc) from the Milky Way galaxy.[4] NGC 6503 may form the remote tip of a long chain of galaxies that extends out into the local void, forming a galaxy filament spanning 26 million light-years (8 Mpc).[9]

The galactic plane of this galaxy is inclined at an angle of 78°±3° to the plane of the sky,[4] with the major axis of its oval profile being aligned along a position angle of 121°.[10] The morphological classification of NGC 6502 is SAB:(s)bc. This indicates a barred spiral galaxy (SAB:) with no inner ring structure (s) and moderately wound spiral arms (bc). However, the ':' notation indicates some uncertainty about the classification. Older works gave it a class of SA(s)bc; i.e. no bar.[6]

A possible bar system has been reported via infrared observations, being viewed end-on from the perspective of the Earth.[11][12] Ultraviolet observations show a young, inner star forming ring encircling the bar.[12] The ring has a radius between 1 and 2.5 kpc from the core.[13] There is a disk of neutral hydrogen that is larger in extent than the optical disk of the galaxy. This extra-planar gas is mostly the result of star formation activity, rather than cold gas that is being accreted.[14] There is evidence for a LINER-type or Seyfert 2 nucleus.[12]

NGC 6503 has one known satellite galaxy,[15] known as KK 242. With a [[stellarass of about 3 million solar masses, KK 242 is on the border between a dwarf irregular galaxy (dIrr) and a dwarf spheroidal galaxy (dSph).[16]

  1. ^ Cite error: The named reference heic1513a was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference simbad was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Kourkchi_et_al_2020 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference O'Meara_2007 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Buta_et_al_2015 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Blanc was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference 1979A&A....74..235M was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Karachentseva_et_al_2023 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Bottema_Gerritsen_1997 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Naray_et_al_2012 was invoked but never defined (see the help page).
  12. ^ a b c Cite error: The named reference Freeland_et_al_2010 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Gouliermis_et_al_2015 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Greisen_et_al_2009 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Koda_et_al_2015 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Karachentsev_et_al_2022 was invoked but never defined (see the help page).