Optical and near-infrared photometry of the Vega-excess star SAO 26804=HD 233517

Abstract. UBVRUHK photometry of the Vega-excess star SAO 26804=HD 233517 and several stars of its environments obtained at the I-meter telescope of the Tien-Shan Observatory in Kazakhstan is presented. It is shown that the star has a later spectral type than has been considered previously. Its effective temperature is estimated by the visual surface brightness method as 4170 K. The star has no excess radiation in the range of 0.3-2.5 J.1.m. A comparison of its IR-excesses with those of other K-type stars with IR-excesses is made. HD 233517 is probably more evolved than SAO 179815=HD 98800 having a very similar intrinsic spectral energy distribution (SED) and the largest IR-excess among K-type stars from the SAO catalogue

Optical and near-infrared photometry of the Vega-excess star SAO 26804=HD 233517

UBVRUHK photometry of the Vega-excess star SAO 26804=HD 233517 and several stars of its environments obtained at the I-meter telescope of the Tien-Shan Observatory in Kazakhstan is presented. It is shown that the star has a later spectral type than has been considered oreviously. Its effective temperature is estimated by the visual surface brightness method as 4170 K. The star has no excess radiation in the range of 0.3-2.5 um. A comparison of its IR-excesses with those of other K-type stars with IR-excesses is made. HD 233517 is probably more evolved than SAO 179815=HD 98800 having a very similar intrinsic spectral energy distribution (SED) and the largest IR-excess among K-type stars from the SAO catalogue

HD 12098 and other results from NainiTal-Cape survey

NainiTal-Cape Survey is a survey started with the aim of searching for new rapidly oscillating Ap stars in the northern hemisphere and has discovered one mono-periodic roAp star HD 12098. The frequency separation of HD 12098 suggests a rotation period of 5.5 day for the star. The discovery of roAp oscillations in HD 12098 and the results of the multi-site observation campaign organized to resolve the ambiguity in the determination of the rotation period of HD 12098 is presented. The results of non oscillating Ap stars discovered in the survey and two promising roAp candidates HD 17431 and HD 207561 are also presented. If confirmed, the variability in HD 207561 will make it the first Am star showing roAp type rapid variability.Comment: 10 pages, 10 figures, JAA sty, To appear in the proceedings of ARIES international workshop on Asteroseismolog

The Detection of Multimodal Oscillations on Alpha UMa

We have used the star camera on the WIRE satellite to observe the K0 III star Alpha UMa, and we report the apparent detection of 10 oscillation modes. The lowest frequency mode is at 1.82 microhertz, and appears to be the fundamental mode. The mean spacing between the mode frequencies is 2.94 microhertz, which implies that all detected modes are radial. The mode frequencies are consistent with the physical parameters of a K0 III star, if we assume that only radial modes are excited. Mode amplitudes are 100 -- 400 micromagnitudes, which is consistent with the scaling relation of Kjeldsen & Beddinge (1995).Comment: ApJ Letters, in press. 14 pages, including 3 figure

Creating Hertzprung-Russel Diagrams Of Open Clusters

This research project is meant to set up Utah State University’s 20 inch diameter telescope and use imaging techniques to do research science with stellar clusters. Using known information taken from stellar catalogues, open clusters will be selected to image. From the im- age, absolute magnitudes or luminocities will be collected from each star in the cluster using imaging software. We will then compare these to their spectral types, or tem- peratures, to create Hertzprung-Russell diagrams of the open clusters. A Hertzprung-Russell (H-R) diagram is a scatter plot of luminocity vs spectral type for stars. The following report will explain target selection of open clusters, imaging methods, and calculations used to cre- ate H-R diagrams of open clusters

Research Note: Rotation and the wind momentum-luminosity relation for extragalactic distances

The effects of axial stellar rotation on the wind-momentum relation (WLR) for determining the extragalactic distances are investigated. Despite the fact that the mass loss rates grow quite a lot with rotation, remarkably the effects on the WLR are found to be very small on the average. As an example, for an average orientation angle between the rotation axis and the line of sight, the luminosity would be overestimated by 5.9 % for a star rotating at 90% of its break-up rotational velocity. Different orientation angles between the rotation axis and the line of sight produce some limited scatter.Comment: 4 pages, 1 figure, in press in A&

New CM diagrams and fundamental parameters of two open clusters in Centaurus: NGC 5460 and NGC 5749

New photoelectric UBV, EDO and Washington observations in the open clusters NGC 5460 and NGC 5749 are used to evaluate cluster membership as well as to determine the fundamental parameters in both clusters. The observations together with a detailed analysis and discussion of the present results will appear in Astron. Astrophys. Suppl. (NGC 5460) and Acta Astronómica (NGC 5749), respectively.Asociación Argentina de Astronomí

Ohio Shrimp

The South Carolina Department of Natural Resources published guides to many threatened animals living in the state. This guide gives information about the Ohio Shrimp, including description, status, habitat, conservation challenges & recommendations, and measures of success