+ Visit NASA.gov + Contact NASA   + Home Collection > NASA  Author > Ayres, T. R.  Author > Little-Marenin, I. R.  Author > Simon, T.  NASA Center > NASA (non Center Specific)  Publication Year > 1981-1990 > 1984  Subject > A-C > Astronomy  Availability Options > Online > PDF  Item/Media Type > Conference Paper  Note: Start a new navigation search by selecting a link above     Previous Record | Next Record + Back to Results   + Printer Friendly Title: Three short-period binaries seen at high-dispersion UX ARI, IOTA TRI and HA5110 Author(s): Little-Marenin, I. R.; Ayres, T. R.; Simon, T. Abstract: The three short-period binary systems UX Ari (P=6.43791 days), iota Tri (P=14.732 days) and RH5110 (P=2.61328 days) represent three different evolutionary stages: (1) an evolved subgiant primary with a secondary still on the main sequence (UX Ari); (2) two evolved G giants that appear to be crossing the Hertzsprung gap for the first time together (iota Tri); and (3) an evolved subgiant that fills its Roche lobe and has lost mass to the secondary to the point where the original secondary is now about 3.5 times as massive as its evolved KOIV companion (HR5110). All three systems show strong UV emission lines indicative of plasmas ranging in temperature from 6000K to 20,000K. X-ray emission was detected from UX Ari and HR5110 indicating hot coronae. The chromospheric, transition region and coronal activity appears to be related primarily to the rotational velocity of the stars (but also to other parameters such as the depth of the convection zone). High-dispersion short-wavelength as well as long-wavelength IUE spectra of all three systems were analyzed. NASA Center: NASA (non Center Specific) Publication Date: Dec 1, 1984 Document Source: CASI Online Source: View PDF File Document ID: 19850012737 Accession ID: 85N21047 Publication Information: NASA. Goddard Space Flight Center Future of Ultraviolet Astronomy Based on Six Years of IUE Res., p 404-407, Number of Pages = 4 Contract-Grant-Task Number: NAG5-146 Price Code: A01 Keywords: BINARY STARS; RADIAL VELOCITY; STELLAR MASS; STELLAR SPECTRA; VARIABLE STARS; G STARS; STELLAR CORONAS; STELLAR TEMPERATURE; ULTRAVIOLET RADIATION; Notes: In NASA. Goddard Space Flight Center Future of Ultraviolet Astronomy Based on Six Years of IUE Res. p 404-407 (SEE N85-20961 11-89) Accessibility: Unclassified; No Copyright; Unlimited; Publicly available; Updated/Added to NTRS: 2008-12-26 + Back to Top + Sponsored by the NASA Scientific and Technical    Information Program + 2004 Vision for Space Exploration + Freedom of Information Act + NASA Web Privacy Policy and Important Notices + NASA Disclaimers, Copyright Notice,    and Terms and Conditions of Use NASA Official: Calvin Mackey Page Curator: NASA Center for AeroSpace Information (help@sti.nasa.gov) Last Updated: July 5, 2007