The star has about 1.46 times the mass of the Sun,[7] along with 1.5 times the radius,[8] and 14 times the luminosity.[9] The abundance of elements other than hydrogen and helium, what astronomers term the star's metallicity, is only 17% of the abundance in the Sun.[3] The star appears to be very young, probably around 231 million years in age, but the margin of error spans 50–347 million years old.[10]
By 2001, the Long Wavelength Spectrometer at the Keck ObservatoryonMauna Kea, Hawaii, was used more accurately to constrain the radius of the dust. It was found to lie within a 5.4 AU radius.[12] The temperature of the dust was estimated as about 340 K.[citation needed] Based on heating from the star, this could place the grains as close as 2.5 AU from Zeta Leporis.[12]
It is now believed[by whom?] that the dust is coming from a massive asteroid belt in orbit around Zeta Leporis, making it the first extra-solar asteroid belt to be discovered. The estimated mass of the belt is about 200 times the total mass in the Solar System's asteroid belt, or 4×1023kg. For comparison, this is more than half the total mass of the Moon. Astronomers Christine Chen and professor Michael Jura found that the dust contained within this belt should have fallen into the star within 20,000 years, a time period much shorter than Zeta Leporis's estimated age, suggesting that some mechanism must be replenishing the belt.[12] The belt's age is estimated to be 3×108 years.[citation needed]
Bobylev's calculations from 2010 suggest that this star passed as close as 1.28 parsecs (4.17 light-years) from the Sun about 861,000 years ago.[5] García-Sánchez 2001 suggested that the star passed 1.64 parsecs (5.34 light-years) from the Sun about 1 million years ago.[4] It was the brightest star in the night sky over 1 million years ago,[13] peaking with an apparent magnitude of -2.05.[13]
^ abcdGutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode:1966PDAUC...1....1G
^ abcMalagnini, M. L.; Morossi, C. (November 1990), "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars", Astronomy and Astrophysics Supplement Series, 85 (3): 1015–1019, Bibcode:1990A&AS...85.1015M
Cote J (1987). "B and A type stars with unexpectedly large colour excesses at IRAS wavelengths". Astronomy and Astrophysics. 181 (1): 77–84. Bibcode:1987A&A...181...77C.
Aumann H. H.; Probst R. G. (1991). "Search for Vega-like nearby stars with 12 micron excess". Astrophysical Journal. 368: 264–271. Bibcode:1991ApJ...368..264A. doi:10.1086/169690.
