AI Velorum

AI Velorum is a <a href="/facts/Variable_star/Ac8mp2gy">variable star</a> in the southern <a href="/facts/Constellation/nBQqgW8A">constellation</a> of <a href="/facts/Vela_(constellation)/sRxGnXAE">Vela</a>, abbreviated AI Vel. It is a prototype for a class of high <a href="/facts/Amplitude/aEckuXJM">amplitude</a> <a href="/facts/Delta_Scuti_variable/EQtxUC4z">Delta Scuti variables</a>. The <a href="/facts/Apparent_visual_magnitude/7pCTF1Me">apparent visual magnitude</a> of this star fluctuates around 6.56, which is just bright enough to be dimly visible to the naked eye. The distance to AI Vel is approximately 327 <a href="/facts/Light_year/IGc5NdQb">light years</a> based on <a href="/facts/Stellar_parallax/ywI9UWEJ">parallax</a> measurements, and it is drifting further away with a <a href="/facts/Radial_velocity/B3NmbVLP">radial velocity</a> of about 9 km/s.
The variability of this star was announced by <a href="/facts/Ejnar_Hertzsprung/M9NYgQr0">E. Hertzsprung</a> in 1931. He found a period of about 2.67 hours, although he later found that period doubtful. In 1937, F. Zagar found irregular variations in the <a href="/facts/Light_curve/zN0wdtaR">light curve</a>. T. Walraven classified it as an <a href="/facts/RR_Lyrae_star/vjoHuKUe">RR Lyrae star</a> in 1952 and suggested it may have two periods that <a href="/facts/Wave_interference/lI5f78I4">interfered</a> 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 of <a href="/facts/Shockwave/CqrG1Xm5">shockwaves</a> that increase light emission.
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 with <a href="/facts/Delta_Scuti_star/EQtxUC4z">Delta Scuti stars</a> of the same period. Together with the <a href="/facts/Space_velocity_(astronomy)/6q1SRvDa">space velocity</a>, these indicated it is instead a normal, high mass star belonging to the younger <a href="/facts/Population_I/8ur1qDRK">population I</a>. By 1985, there was some evidence for an increase in the second period by one part in 105. At least two additional periodicities were identified by Walraven and associates in 1992.
The <a href="/facts/Stellar_classification/dYrIuK9H">stellar classification</a> of AI Vel is A9IV/V, matching a slightly <a href="/facts/Stellar_evolution/Qa4vAGmn">evolved</a> star that is moving away from the <a href="/facts/Main_sequence/DJ3Wq8kd">main sequence</a>. It is 479 million years old and is estimated to have 1.55 times the <a href="/facts/Mass_of_the_Sun/j6Auhku8">mass of the Sun</a>. As a Delta Scuti variable, the brightness of the star ranges in magnitude from 6.15 down to 6.76. Evolutionary models published with <a href="/facts/Gaia_Data_Release_3/dlvcdkoN">Gaia Data Release 3</a> show it to be approaching the end of its main sequence life.

AI Velorum open-in-new

AI Velorum