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A catalog of K giants at the South Galactic Pole - Broadband and DDO photometry and radial velocities
We describe a sample of K giants at the South Galactic Pole, selected toexamine the chemical and kinematical properties of stars perpendicularto the galactic plane and to measure the local column density of thedisk. We report velocities, abundances, absolute magnitudes, andbroadband BV photometry for over 500 giants.
| A kinematic and abundance survey at the galactic poles
The DDO intermediate band system is used to obtain detailed informationabout abundance gradients and velocity dispersions in the galaxy, withan emphasis on the properties of halo stars in the range of from 1 to 5kpc. The DDO abundance index is calibrated agianst (Fe/H) for metal-poorstars, with a resulting gradient of about -0.2 per kpc. However, whenthe sample is divided into two subsamples with (Fe/H) less than -0.5 andequal to or greater than -0.5, the gradients are -0.14 and 0.00,respectively. DDO observations of about 1000 stars, mostly G5-K5 giants,show that the velocity dispersion increases both with decrease inmetallicity and increase in z distance. The abundances found for high-zstars are similar to the A-star results of Rodgers (1971) in that abouthalf the K giants above 1 kpc appear to have solar abundances.
| Intermediate band photometry of late-type stars. II - Some stellar groups
Observations on the (R, I) system and a modified Stromgren system ofmembers of six stellar groups are used to demonstrate the chemicalhomogeneity of some 70% or 80% of the members assigned to the groups onthe basis of kinematics. The groups discussed are the Hyades, Wolf 630,Arcturus, Groombridge 1830, and Kapteyn's Star Groups as well as ananonymous group of a half dozen subdwarfs with (U, V) near (-150, -320)km/s. Standards for a previously described photometric system areextended, and additional F- and G-type standards for the (R, I) systemare presented. A simple relation is derived for computing the Fe/Habundance ratio for most stars in the corrected (R-I) interval from +0.2to +0.45 magnitude.
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תצפית ומידע אסטרומטרי
| קבוצת-כוכבים: | לויתן |
| התרוממות ימנית: | 00h39m43.93s |
| סירוב: | -24°11'04.9" |
| גודל גלוי: | 9.314 |
| תנועה נכונה: | 6.2 |
| תנועה נכונה: | -1 |
| B-T magnitude: | 10.988 |
| V-T magnitude: | 9.453 |
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