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Hipparcos red stars in the HpV_T2 and V I_C systems
For Hipparcos M, S, and C spectral type stars, we provide calibratedinstantaneous (epoch) Cousins V - I color indices using newly derivedHpV_T2 photometry. Three new sets of ground-based Cousins V I data havebeen obtained for more than 170 carbon and red M giants. These datasetsin combination with the published sources of V I photometry served toobtain the calibration curves linking Hipparcos/Tycho Hp-V_T2 with theCousins V - I index. In total, 321 carbon stars and 4464 M- and S-typestars have new V - I indices. The standard error of the mean V - I isabout 0.1 mag or better down to Hp~9 although it deteriorates rapidly atfainter magnitudes. These V - I indices can be used to verify thepublished Hipparcos V - I color indices. Thus, we have identified ahandful of new cases where, instead of the real target, a random fieldstar has been observed. A considerable fraction of the DMSA/C and DMSA/Vsolutions for red stars appear not to be warranted. Most likely suchspurious solutions may originate from usage of a heavily biased color inthe astrometric processing.Based on observations from the Hipparcos astrometric satellite operatedby the European Space Agency (ESA 1997).}\fnmsep\thanks{Table 7 is onlyavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/397/997
| The 74th Special Name-list of Variable Stars
We present the Name-list introducing GCVS names for 3153 variable starsdiscovered by the Hipparcos mission.
| The medium dispersion prism of the UK Schmidt Telescope
The UK 1.2-m Schmidt Telescope acquired its first full apertureobjective prism in 1975. This was a very low dispersion prism which wasfound to be particularly useful in searching for faint QSO's. However,the dispersion in the red is so low that nearly all plates have beentaken on the blue-sensitive IIIa J emulsion, and it has been extremelydifficult to identify quasars with redshifts larger than z=3. It was,therefore, decided to obtain a second objective prism having a threetimes higher dispersion. It is expected that this prism will make itpossible to conduct searches for quasars having redshifts greater thanthe long-standing limit at z approximately 3.5. The prism should also beuseful for stellar classification work in the UV/blue part of thespectrum. A description is presented of some results obtained during therecent commissioning run with the new prism.
| 1115 Å ultraviolet stellar photometry
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Observation and Astrometry data
| Constellation: | Γνώμων |
| Right ascension: | 16h31m59.45s |
| Declination: | -44°53'12.4" |
| Apparent magnitude: | 7.615 |
| Distance: | 361.011 parsecs |
| Proper motion RA: | 11.6 |
| Proper motion Dec: | -4.7 |
| B-T magnitude: | 9.975 |
| V-T magnitude: | 7.81 |
Catalogs and designations:
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