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]

List

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.

Star	Maximum magnitude	Minimum magnitude	Period (in days)	Spectral type
SX Phoenicis^{[n 1]}	6.76	7.53	0.055	A2V
HD 94033	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

Notes

↑ ^1.0 ^1.1 double-mode

References

↑ Stankov, A.; Sinachopoulos, D.; Elst, E.; Breger, M. (February 2002). "Stromgren photometry of SX Phe = HD 223065". Communications in Asteroseismology 141: 72-83. https://ui.adsabs.harvard.edu/abs/2002CoAst.141...72S. Retrieved 20 February 2022.
↑ "GCVS Variability Types". General Catalogue of Variable Stars. Moscow, Russia: Russian Foundation for Basic Research, Sternberg Astronomical Institute. http://www.sai.msu.su/gcvs/gcvs/iii/vartype.txt.
↑ Burki, G.; Mayor, M. (1986). "Radial velocities with CORAVEL - Results on stellar variability and duplicity". Christchurch, New Zealand: Dordrecht, D. Reidel Publishing Co.. p. 392. Bibcode: 1986IAUS..118..385B.
↑ Breger, M. (Jan 1980). "The nature of dwarf Cepheids. V - Analysis and conclusions". Astrophysical Journal, Part 1 235: 156. doi:10.1086/157620. Bibcode: 1980ApJ...235..153B.
↑ McNamara, D. H. (April 1995). "Period-luminosity relations of SX Phoenicis stars". Astronomical Journal 109 (4): 1751–1756. doi:10.1086/117405. Bibcode: 1995AJ....109.1751M.
↑ Templeton, Matthew. "Variable Star of the Season: Delta Scuti and the Delta Scuti variables". American Association of Variable Star Observers. https://www.aavso.org/vsots_delsct.
↑ Jeon, Young-Beom; Lee, Myung Gyoon; Kim, Seung-Lee; Lee, Ho (July 2004). "SX Phoenicis Stars in the Globular Cluster NGC 5466". The Astronomical Journal 128 (1): 11. doi:10.1086/421735. Bibcode: 2004AJ....128..287J.
↑ Santolamazza, P.; Marconi, M.; Bono, G.; Caputo, F.; Cassisi, S.; Gilliland, R. L. (June 2001). "Linear Nonadiabatic Properties of SX Phoenicis Variables". The Astrophysical Journal 554 (2): 1124–1140. doi:10.1086/321408. Bibcode: 2001ApJ...554.1124S.

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/SX Phoenicis variable. Read more

[double-9] 1.0 ^1.1 double-mode

[Stankov-1] Stankov, A.; Sinachopoulos, D.; Elst, E.; Breger, M. (February 2002). "Stromgren photometry of SX Phe = HD 223065". Communications in Asteroseismology 141: 72-83. https://ui.adsabs.harvard.edu/abs/2002CoAst.141...72S. Retrieved 20 February 2022.

[GCVS-2] "GCVS Variability Types". General Catalogue of Variable Stars. Moscow, Russia: Russian Foundation for Basic Research, Sternberg Astronomical Institute. http://www.sai.msu.su/gcvs/gcvs/iii/vartype.txt.

[burki_mayor86-3] Burki, G.; Mayor, M. (1986). "Radial velocities with CORAVEL - Results on stellar variability and duplicity". Christchurch, New Zealand: Dordrecht, D. Reidel Publishing Co.. p. 392. Bibcode: 1986IAUS..118..385B.

[apj235-4] Breger, M. (Jan 1980). "The nature of dwarf Cepheids. V - Analysis and conclusions". Astrophysical Journal, Part 1 235: 156. doi:10.1086/157620. Bibcode: 1980ApJ...235..153B.

[aj109-5] McNamara, D. H. (April 1995). "Period-luminosity relations of SX Phoenicis stars". Astronomical Journal 109 (4): 1751–1756. doi:10.1086/117405. Bibcode: 1995AJ....109.1751M.

[aavso-6] Templeton, Matthew. "Variable Star of the Season: Delta Scuti and the Delta Scuti variables". American Association of Variable Star Observers. https://www.aavso.org/vsots_delsct.

[aj128-7] Jeon, Young-Beom; Lee, Myung Gyoon; Kim, Seung-Lee; Lee, Ho (July 2004). "SX Phoenicis Stars in the Globular Cluster NGC 5466". The Astronomical Journal 128 (1): 11. doi:10.1086/421735. Bibcode: 2004AJ....128..287J.

[apj554-8] Santolamazza, P.; Marconi, M.; Bono, G.; Caputo, F.; Cassisi, S.; Gilliland, R. L. (June 2001). "Linear Nonadiabatic Properties of SX Phoenicis Variables". The Astrophysical Journal 554 (2): 1124–1140. doi:10.1086/321408. Bibcode: 2001ApJ...554.1124S.