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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
| New periodic variables from the Hipparcos epoch photometry Two selection statistics are used to extract new candidate periodicvariables from the epoch photometry of the Hipparcos catalogue. Theprimary selection criterion is a signal-to-noise ratio. The dependenceof this statistic on the number of observations is calibrated usingabout 30000 randomly permuted Hipparcos data sets. A significance levelof 0.1 per cent is used to extract a first batch of candidate variables.The second criterion requires that the optimal frequency be unaffectedif the data are de-trended by low-order polynomials. We find 2675 newcandidate periodic variables, of which the majority (2082) are from theHipparcos`unsolved' variables. Potential problems with theinterpretation of the data (e.g. aliasing) are discussed.
| Valinhos 2.2 micron survey of the southern galactic plane. II - Near-IR photometry, IRAS identifications and nature of the sources Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1987A&AS...71...39E&db_key=AST
| Valinhos 2.2 micron survey of the Southern Galactic plane Positions and infrared photometry of 338 sources This paper reports on JHKLM photometric measurements of 338 brightinfrared stars found in a 2.2-micron survey of a 10 x 100-deg lane ofthe Southern Galactic plane. More than 2/3 of the objects are notidentified with catalogued stars and are likely to belong-period-variable or reddened giant or supergiant stars.
| Régions H II de l'hémisphère austral Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970A&AS....3....1G&db_key=AST
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Takýmyýldýz: | Pergel |
Sað Açýklýk: | 14h51m21.69s |
Yükselim: | -59°30'12.7" |
Görünürdeki Parlaklýk: | 7.271 |
Uzaklýk: | 230.415 parsek |
özdevim Sað Açýklýk: | -2.4 |
özdevim Yükselim: | -15.8 |
B-T magnitude: | 9.618 |
V-T magnitude: | 7.465 |
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