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Four-Color And Hβ Photometry Of The Galactic Cluster Ngc 7790, Edward G. Schmidt
Four-Color And Hβ Photometry Of The Galactic Cluster Ngc 7790, Edward G. Schmidt
Edward Schmidt Publications
Observations have been obtained on the four-color and Hβ system of 16 stars in the field of NGC 7790. These represent virtually all of the stars which are in the B-star region of the cluster color-magnitude diagram. I discuss the membership of these stars and find three which are possibly field stars. The remaining stars indicate a true distance modulus of 11.98 ± 0.13 for the cluster and a color excess of E(b – y) = 0.403.
Simultaneous X-Ray And Optical Observations Of An Ursae Majoris During A Low State, Paula Szkody, Edward G. Schmidt, Lidia Crosa, Robert Schommer
Simultaneous X-Ray And Optical Observations Of An Ursae Majoris During A Low State, Paula Szkody, Edward G. Schmidt, Lidia Crosa, Robert Schommer
Edward Schmidt Publications
X-ray observations throughout the orbital cycle of AN UMa during its low state were conducted with the Einstein Observatory simultaneously with ground-based optical UBV photometry and spectroscopy. The observed low X-ray flux of 7 × 10–13 ergs cm–2 s–1 is a factor of 40 below the high-state X-ray flux, and Fx/Fopt is about a factor of 50 lower than for AM Her and 2A 0311–227. There is marginal evidence for an X-ray eclipse coincident with an optical minimum and for increased X-ray flux at magnetic phase 0.4 which does not correlate with any optical …