NGC 2506

NGC 2506
An image of NGC 2506
Observation data (J2000 epoch)
Right ascension08h 00m 01.0s[1]
Declination−10° 46′ 12″[1]
Distance12.7 ± 1.4 kly (3.88 ± 0.42 kpc)[2]
Apparent magnitude (V)7.6[3]
Apparent dimensions (V)12′[4]
Physical characteristics
Radius18.5 ly[4]
Estimated age2.09±0.14 Gyr[2]
Other designationsCaldwell 54, Cr 170, Mel 80[5]
Associations
ConstellationMonoceros
See also: Open cluster, List of open clusters
Map showing the location of NGC 2506

NGC 2506 (also known as Caldwell 54) is a mildly-elongated[6] open cluster of stars in the equatorial constellation of Monoceros, located at a distance of 12.7 kly[2] from the Sun near the Galactic anti-center.[4] It was discovered by William Herschel in 1791.[7] The cluster lies around 10,000 ly from the Galactic Center and about 1,600 ly above the Galactic plane.[4] It is of intermediate age,[2] estimated at around two billion years.[2] The cluster has an angular radius of 12′ and a core radius of 4.8′.[8]

At least 94 probable members have been identified within the field of NGC 2506 based upon their radial velocities. Compared to the Sun, the cluster is moderately metal-poor with an iron abundance of [Fe/H] = –0.3 dex.[9] It shows indications of mass segregation, with the lower mass members being more likely to be in the outer parts of the cluster. This is the result of exchange of kinetic energy during encounters between the members.[10] Twelve blue straggler stars have been located in the cluster, with three of them showing short-period oscillation. Fourteen Gamma Doradus variables have been found, as well as two detached eclipsing binaries,[6] and three Delta Scuti stars.[11]

  1. ^ a b Cite error: The named reference Xin2005 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Rangwal2019 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference seds was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference O'Meara2016 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference simbad was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Arentoft2007 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Erdmann was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference kharchenko2005 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Anthony-Twarog2018 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Lee2013 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Kim2001 was invoked but never defined (see the help page).