NGC 6193 (also known as Caldwell 82) is open cluster containing 27 stars in the constellationAra, visible to the unaided eye.[1] NGC 6193 lies at the center of the Ara OB1 association, which extends over a square degree. The cluster is associated with (and provides the energizing radiation for) neighboring regions of the nebulosity NGC 6188.
Cluster members
NGC 6193 is dominated by two O class multiple star systems within 10" of each other at the centre of the cluster, and a probable binary B0 giant. There are at least 20 other early B stars in the cluster, of 9th and 10th magnitude.
^ abcdVazquez, R. A.; Feinstein, A. (1992). "Binary stars - Another effect contributing to the supposed abnormal extinction law in NGC 6193?". Astronomy and Astrophysics Supplement Series. 92: 863. Bibcode:1992A&AS...92..863V.
^ abcdeHerbst, W.; Havlen, R. J. (1977). "ARA OB1, NGC 6193 and ARA R1 - an optical study of a very young southern complex". Astronomy and Astrophysics Supplement Series. 30: 279. Bibcode:1977A&AS...30..279H.
^Moffat, A. F. J.; Vogt, N. (1973). "Southern open stars clusters. III. UBV-Hbeta photometry of 28 clusters between galactic longitudes 297d and 353d". Astronomy and Astrophysics Supplement Series. 10: 135. Bibcode:1973A&AS...10..135M.