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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.
| A new photometric WBVR system
A description of the new broad-band photometric system, WBVR, is given.It is shown that WBVR is close to the UBVR system but is defined bystrictly fixed response curves and the primary standard. Theconstruction of a network of secondary standards distributed uniformlyin the northern sky, as well as the coordination of the magnitudes ofthe standards to the self-consistent system are discussed. All standardsare examined for a possible brightness variability and it is found thatno light variability exceeding 0.015 mag in amplitude is present andthat their average magnitude shows stability on a scale of severalyears. The individual WBVR observations of the standards are presentedin tables.
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Osservazione e dati astrometrici
| Costellazione: | Idro |
| Ascensione retta: | 03h25m12.11s |
| Declinazione: | -78°39'58.4" |
| Magnitudine apparente: | 8.578 |
| Distanza: | 699.301 parsec |
| Moto proprio RA: | 4 |
| Moto proprio Dec: | 2 |
| B-T magnitude: | 10.912 |
| V-T magnitude: | 8.771 |
Cataloghi e designazioni:
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