AnSX 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]
The following list contains selected SX Phoenicis variable that are of interest to amateur or professional astronomy. Unless otherwise noted, the given magnitudes are in the V-band.[citation needed]
| Star |
Maximum magnitude |
Minimum magnitude |
Period (in days) |
Spectral type |
|---|---|---|---|---|
| SX Phoenicis[n 1] | 6.76 | 7.53 | 0.055 | A2V |
| KZ Hydrae | 9.46 | 10.26 | 0.060 | B9III/IV |
| DY Pegasi | 10.00 | 10.56 | 0.073 | F5 |
| CY Aquarii | 10.42 | 11.20 | 0.061 | B8 |
| AE Ursae Majoris[n 1] | 10.86 | 11.52 | 0.086 | A9 |
| XX Cygni | 11.28 | 12.13 | 0.135 | A5-F5 |
| BL Camelopardalis | 12.92 | 13.25 | 0.039 | |
| BX Sculptoris | 13.42 | 13.71 | 0.037 | A |
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|---|---|---|---|---|---|---|---|---|---|
| Pulsating |
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| Eruptive |
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| Cataclysmic |
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| Rotating |
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| Eclipsing |
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