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The association of IRAS sources and 12CO emission in the outer Galaxy
We have revisited the question of the association of CO emission withIRAS sources in the outer Galaxy using data from the FCRAO Outer GalaxySurvey (OGS). The availability of a large-scale high-resolution COsurvey allows us to approach the question of IRAS-CO associations from anew direction - namely we examined all of the IRAS sources within theOGS region for associated molecular material. By investigating theassociation of molecular material with random lines of sight in the OGSregion we were able to construct a quantitative means to judge thelikelihood that any given IRAS-CO association is valid and todisentangle multiple emission components along the line of sight. Thepaper presents a list of all of the IRAS-CO associations in the OGSregion. We show that, within the OGS region, there is a significantincrease ( ~ 22%) in the number of probable star forming regions overprevious targeted CO surveys towards IRAS sources. As a demonstration ofthe utility of the IRAS-CO association table we present the results ofthree brief studies on candidate zone-of-avoidance galaxies with IRAScounterparts, far outer Galaxy CO clouds, and very bright CO clouds withno associated IRAS sources. We find that ~ 25% of such candidate ZOAGsare Galactic objects. We have discovered two new far outer Galaxystar-forming regions, and have discovered six bright molecular cloudsthat we believe are ideal targets for the investigation of the earlieststages of sequential star formation around HII regions. Finally, thispaper provides readers with the necessary data to compare othercatalogued data sets with the OGS data.Tables 1, 2 and A1 are only available in electronic form at the CDS viaanonymous ftp to\ cdsarc.u-strasbg.fr (130.79.128.5) or via\http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/399/1083
| The Onset of Pulsation in Red Giants
The Hippercos astrometric and photometric database has many applicationsfor undergraduate research projects. As one example, we haveinvestigated the onset of variability in red giants by noting the excessscatter (above and beyond the instrumental scatter) in the Hipparcosphotometric measurements of 7600 giants with +1.35 < (V-I) <+1.70. Microvariability (0.00 < deltaV < 0.01) sets in graduallyfor (V-I) > + 1.55. These are, however, reddened colors, but thesmall contamination by distant reddened supergiants may be offset by thecontamination by reddened earlier-type giants. According to three recenteffective temperature scales, these two (V-I) colors correspond to 4085K and 3905 K, respectively, with an internal uncertaintly of +/- 10 K.
| The 74th Special Name-list of Variable Stars
We present the Name-list introducing GCVS names for 3153 variable starsdiscovered by the Hipparcos mission.
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