VBLUW photometry of the association Sco OB1 (containing the open cluster NGC 6231). A discussion on the evolutionary status of the hypergiant zeta 1 Sco (B1 Ia +)
1984 (English)In: Astronomy and Astrophysics Supplement Series, ISSN 0365-0138, Vol. 58, no 3, 537-548548 p.Article in journal (Refereed) Published
VBLUW photometry of nearly 190 stars in the very young association Sco OB1, including the cluster NGC 6231, is presented and discussed. Temperature and surface gravity are determined with the aid of theoretical colours. Individual reddenings are also obtained. The distance modulus ( m- M) 0=11.00plusmn0.25 is similar to the value found by Shobbrook (1983). It appears that the reddening is not uniformly distributed across the association (~2degtimes1deg), but that areas of low and high reddening, varying from E( B- V) J=0.35 up to 0.67, can be distinguished. Practically all reddening is caused by dust in the local spiral arm up to a distance of at most 700 pc from the Sun. The Sagittarius-Carina arm where Sco OB1 is situated is practically transparent over a distance of ~0.5 kpc. The kinematical age of ~10 6 yr is in reasonable agreement with the average evolutionary age of ~(3.6plusmn0.6)times10 6 yr of the 12 brightest stars. The evolutionary status of the hypergiant zeta 1 Sco (B1 Ia +) is discussed
Place, publisher, year, edition, pages
1984. Vol. 58, no 3, 537-548548 p.
Bibliography, Experimental/ interstellar matter, stellar atmospheres, stellar clusters and associations, stellar evolution, stellar photometry, supergiant stars, visible astronomical observations/ stellar photoelectric photometry, Scorpius OB1 association, stellar OB association, star cluster, zeta Scorpii, visible, OB-type stars, association age, effective temperatures, near-UV, AD 1976 to 1977, foreground interstellar reddening, two-colour diagram, colour-magnitude diagram, VBLUW photometry, open cluster, NGC 6231, evolutionary status, hypergiant, B1 Ia +, very young association, surface gravity, theoretical colours, distance modulus, E( B- V) J, local spiral arm, Sagittarius-Carina arm, kinematical age, evolutionary age/ A9580J Photographic region astronomical observations A9710C Stellar interiors, evolution, nucleosynthesis, and ages A9710E Stellar atmospheres, radiative transfer, opacity, and line formation A9710R Stellar radiation and spectra A9710V Stellar distances, parallaxes, and space density A9720P Supergiant stars A9820C Associations of stars (OB, T, etc.) A9820E Open clusters A9840B Interstellar matter
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:uu:diva-197183ISI: 2421794OAI: oai:DiVA.org:uu-197183DiVA: diva2:611961