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Three-color surface photometry of a selected sample of early-type galaxies. I - Observations and data reduction
This paper presents the results of two or three color surface photometryfor a sample of 36 early-type galaxies obtained at the Canada FranceHawaii Telescope with CCD cameras. The calibration and data reductionprocedures are described. A comparison of the results with previous workis made for NGC 3379. For each galaxy the B surface brightness profilealong the major axis, as well as ellipticity and color profiles aredisplayed.
| Transformation equations and other aids for VRI photometry
Transformations among VRI systems are commonly beset by Paschen-jumpeffects, for which fully satisfactory allowance has not previously beenmade. This paper describes two new techniques which are based on thework of Gutierrez-Moreno, and which allow fully for the effects of thePaschen jump. Values of E(V-R)/E(B-V) and E(R-I)/E(B-V) are also givenfor the Cousins system for a wide range of temperatures. These and thenew techniques contribute to a set of new transformation relations whichapply for most VRI systems; the status of the remaining systems isreviewed, and future work needed for them is described. Two majorsources of Cousins VRI data underlie the new relations; the consistencyof these sources is reviewed and found to be generally satisfactory,although more work on this question is needed. Finally, three tables oftransformed standard-star and other data are given for the Cousins andJohnson systems, and a description of ways to reproduce the latter ispresented.
| UBV Photometry of Equatorial Stars
Not Available
| Standardization of Broadband Photometry of Equatorial Standards
Not Available
| Four UBVRI sequences near bright Virgo galaxies
Four photoelectric sequences have been established around brightgalaxies in the Virgo cluster. UBVRI observations of 37 stars, mostly inthe range of V between 9 and 15, are given and serious discrepanciesbetween the present data and earlier UBV work are described.
| A UBVRI equatorial extinction star network
An equatorial-extinction star network, based on 1503 observations of 37stars, is presented. These results together with those of Crawford etal. (1971) provide a well-determined UBVRI extinction network.Identification charts are included.
| Distances to eclipsing binaries. III - Masses, radii, and absolute magnitudes of 96 stars
Distances to, and absolute magnitudes of, 96 components of eclipsingbinaries with well-determined absolute dimensions have been computedusing V-R photometry. The calculations take into account interstellarreddening, which is estimated from existing UBV and uvby-betaphotometry, as well as photometric proximity effects. The resultingabsolute magnitudes, dimensions, and masses are compared with zero-agemain sequences predicted by theory. Theory is in good agreement with theobserved data for stars more massive than the sun if a composition (X,Y, Z) = (0.66 + or - 0.03, 0.303 + or - 0.03, 0.037 + or - 0.005) ischosen. The corresponding helium-to-hydrogen number ratio is 0.115 + or- 0.02, in agreement with previous estimates.
| A UBV equatorial-extinction star network
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971PASP...83..652C&db_key=AST
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Membre dels grups següents:
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Dades d'Observació i Astrometria
| Constel·lació: | Virgo |
| Ascensió Recta: | 12h47m14.83s |
| Declinació: | +07°00'28.6" |
| Magnitud Aparent: | 8.448 |
| Distancia: | 264.55 parsecs |
| Moviment propi RA: | -15.5 |
| Moviment propi Dec: | -7.7 |
| B-T magnitude: | 9.955 |
| V-T magnitude: | 8.573 |
Catàlegs i designacions:
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