With an estimated age of 660 million years,[11][12] this is a relatively young
Lambda Boötis star.[15] The
stellar classification of A8 Vn kA6[3] shows this peculiarity, with the kA6 notation indicating weaker than normal
calcium K-lines in the
spectrum. The 'n' following the
main sequenceluminosity class of V indicates the
absorption lines in the spectrum are broad and nebulous. This is caused by the rapid spin of the star, which has a high
projected rotational velocity of 206 km/s.[10] Spectroscopy shows narrow, time-varying absorption features being caused by circumstellar gas moving toward the star. This is not the result of interstellar matter, but a shell of gas along the orbital plane. Alpha Pictoris is categorized as a rapidly rotating
shell star that may have recently ejected mass from its outer atmosphere.[9][16]
Data from the Hipparcos mission indicate this may be an unresolved
binary system with a companion orbiting at a
semimajor axis of around 1
AU, or the same distance that the Earth orbits from the Sun.[15] Alpha Pictoris is an X-ray source, which is unusual for an A-type star since stellar models don't predict them to have magnetic dynamos. This emission may instead be originating from the companion.[9][19]
^
abcdJohnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110.
Bibcode:
1966CoLPL...4...99J.
^Wilson, R. E. (1953). "General Catalogue of Stellar Radial". Carnegie Institute Washington D.C. Publication. Washington D.C.: Carnegie Institution Publication 601.
Bibcode:
1953GCRV..C......0W.
^
abcPizzolato, N.; Maggio, A.; Sciortino, S. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases", Astronomy and Astrophysics, 361: 614–628,
Bibcode:
2000A&A...361..614P
^
abMalagnini, 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