The variability of this star was announced byE. Hertzsprung in 1931. He found a period of about 2.67 hours,[11] although he later found that period doubtful. In 1937,F. Zagar found irregular variations in thelight curve.[12]T. Walraven classified it as anRR Lyrae star in 1952 and suggested it may have two periods thatinterfered with each other. The primary period was found to be 2.678 hours while the secondary is 2.069 hours; together their interference creates a beat period of 9.100 hours. The height of the maximum was found to be greater than the depth of the minimum, which may be the result ofshockwaves that increase light emission.[13]
As an RR Lyrae variable, AI Velorum should be a low mass, evolved star. However,M. Breger in 1977 noted the period and surface gravity showed a match withDelta Scuti stars of the same period. Together with thespace velocity, these indicated it is instead a normal, high mass star belonging to the youngerpopulation I.[14] By 1985, there was some evidence for an increase in the second period by one part in 105.[15] At least two additional periodicities were identified by Walraven and associates in 1992.[10]
Thestellar classification of AI Vel is A9IV/V,[4] matching a slightlyevolved star that is moving away from themain sequence. It is 479 million years old and is estimated to have 1.55 times themass of the Sun.[7] As a Delta Scuti variable, the brightness of the star ranges in magnitude from 6.15 down to 6.76.[3] Evolutionary models published withGaia Data Release 3 show it to be approaching the end of its main sequence life.[2]
^abWalraven, Th.; et al. (January 1992), "Discovery of additional pulsation modes in AI Velorum",Monthly Notices of the Royal Astronomical Society,254:59–66,Bibcode:1992MNRAS.254...59W,doi:10.1093/mnras/254.1.59.
^Hertzsprung, E. (August 1931), "A new variable star of short period",Bulletin of the Astronomical Institutes of the Netherlands,6: 147,Bibcode:1931BAN.....6..147H.
^van Hoof, A. (June 1937), "Photographic photometry of AI Velorum on Johannesburg plates",Bulletin of the Astronomical Institutes of the Netherlands,8: 172,Bibcode:1937BAN.....8..172V.
^Walraven, Th. (July 1952), "On the light-variation of AI Velorum",Bulletin of the Astronomical Institutes of the Netherlands,11: 421,Bibcode:1952BAN....11..421W.
^Bates, B.; Halliwell, D. R. (October 1985), "Observations of the light and colour variations of AI Velorum using an acousto-optic filter photometer",Astronomy and Astrophysics,151:403–407,Bibcode:1985A&A...151..403B.
Guiglion, G.; et al. (December 2012), Boissier, S.; et al. (eds.), "The Baade-Wesselink projection factor of the δ-Scuti stars AI Vel and β Cas",SF2A-2012: Proceedings of the Annual Meeting of the French Society of Astronomy and Astrophysics:337–342,Bibcode:2012sf2a.conf..337G.
Simon, N. R. (April 1979), "On the oscillations of AI Velorum",Astronomy and Astrophysics,74:30–37,Bibcode:1979A&A....74...30S.
Elst, E. W. (November 1975), "V photometric observations of AI Vel",Astronomy and Astrophysics Supplement Series,22:221–233,Bibcode:1975A&AS...22..221E.
Barnes, T. G., III; Moffett, T. J. (January 1975), "Photometric properties and evidence of duplicity for SZ Lyncis",Astronomical Journal,80:48–55,Bibcode:1975AJ.....80...48B,doi:10.1086/111712.{{citation}}: CS1 maint: multiple names: authors list (link)
Petersen, J. O.; Jørgensen, H. E. (March 1972), "Pulsation of models in the lower part of the cepheid instability strip and properties of AI Velorum and delta Scuti stars",Astronomy and Astrophysics,17: 367,Bibcode:1972A&A....17..367P.
Walraven, Th. (February 1955), "The pulsations of AI Velorum, SX Phoenicis and RR Lyrae",Bulletin of the Astronomical Institutes of the Netherlands,12: 223,Bibcode:1955BAN....12..223W.
Gratton, L. (May 1953), "On the velocity curve of AI Velorum",Bulletin of the Astronomical Institutes of the Netherlands,12: 31,Bibcode:1953BAN....12...31G.
Gratton, L.; Lavagnino, C. J. (1953), "Spektrographische Beobachtungen des veränderlichen AI Velorum. Mit 8 Textabbildungen",Zeitschrift für Astrophysik,32: 69,Bibcode:1953ZA.....32...69G.
