SX Phoenicis variable

A visual band light curve for SX Phoenicis, adapted from Stankov et al. (2002)[1]

An SX Phoenicis variable is a type of variable star. These stars exhibit a short period pulsation behavior that varies on time scales of 0.03–0.08 days (0.7–1.9 hours). They have spectral classifications in the range A2-F5 and vary in magnitude by up to 0.7.[2] Compared to the Sun, these stars have a lower metallicity, which means they have a reduced abundance of elements other than hydrogen and helium. They also have relatively high space velocity and low luminosities for stars of their stellar classification.[3][4] These properties distinguish the SX Phoenicis variables from their cousins, the Delta Scuti variables. The latter have longer periods, higher metallicity and large amplitudes.[5]

SX Phoenicis variables are found primarily in globular clusters and galactic halos. The variability cycle has a period-luminosity relation.[6] All known SX Phoenicis variables in globular clusters are blue straggler stars.[7] These are stars that appear more blue (having a higher temperature) than the main sequence stars in the same cluster that have similar luminosities.[8]

  1. ^ Cite error: The named reference Stankov was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference GCVS was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference burki_mayor86 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference apj235 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference aj109 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference aavso was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference aj128 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference apj554 was invoked but never defined (see the help page).