BVR photoelectric sequences for selected fields in the Palomar Sky Survey and the magnitude-diameter relation

Humphreys, R. M.; Landau, R.; Ghigo, F. D.; Zumach, W.; Labonte, A. E.

doi:10.1086/115883

Cited by 32 publications

(31 citation statements)

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“…Mohan & Crézé (1987) find a correction of 0.162(B − V) + 0.048(U − B) for IIa0 plates with the GG385 filter. Humphreys et al (1991;their Fig. 1b) also find a positive slope in (B − V) for blue (103a0) plates.…”

Section: Color Correctionmentioning

confidence: 68%

“…It has the advantage of not being affected by the saturation of the image of bright stars, especially on copies of plates. This is the method used for the National Geographic -Palomar Observatory Sky Survey (King & Raff 1977;Humphreys et al 1991), the ESO/SRC Sky Atlas (King et al 1981;Pierre 1986), the Second Cape Photographic Catalogue (de Vegt et al 1993), among others (for a review of older studies, see Hearnshaw 1996).…”

Section: Measuring the Platesmentioning

confidence: 99%

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Stellar photometry with the Carte du Ciel plates

Lamareille

Thiévin

Fournis

et al. 2003

A&A

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Abstract. We present a method for measuring the magnitude of stars on the photographic plates of the Carte du Ciel. There are between 95 and 162 non-variable stars of known B and V magnitudes on each plate, which covers an area of 2 square degrees on the sky. The densities of these stars, measured with a commercial scanner, are used to calibrate the density-to-intensity conversion relation of each plate. The derived magnitudes decrease linearly away from the center and then brighten again more steeply toward the edge, presumably because of vigneting and coma. A distance-and density-dependent correction for these two effects is determined for each plate; this is necessary if one wants to determine the light curve of a given star with plates belonging to adjacent fields. We find a magnitude-dependent color effect, which is not understood, and thus not corrected for. The final accuracy of the calibration depends on the distance from the center of the plate, and is optimal near the center. The method is tested on five known variable stars.

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Section: Color Correctionmentioning

confidence: 68%

Section: Measuring the Platesmentioning

confidence: 99%

Stellar photometry with the Carte du Ciel plates

Lamareille

Thiévin

Fournis

et al. 2003

A&A

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“…The apparent magnitudes in the MAPS catalog are given as photographic O magnitudes, while the USNO catalog measures B magnitudes. To convert the O magnitude from MAPS and the B USNO to the standard B J magnitude in Johnson's system we used the linear correlations that we found using the BVR photoelectric photometry for 426 stars in 49 Palomar Sky Survey fields (Humphreys et al 1991). The following expressions are used to transform the apparent magnitude to the B J magnitude:…”

Section: Optical Nuclear Luminosities Of Compact Agnmentioning

confidence: 99%

Radio-optical scrutiny of compact AGN: correlations between properties of pc-scale jets and optical nuclear emission

Arshakian¹,

Torrealba

Chavushyan

et al. 2010

A&A

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Aims. We study the correlations between the VLBA (Very Long Baseline Array) radio emission at 15 GHz, extended emission at 151 MHz, and optical nuclear emission at 5100 Å for a complete sample of 135 compact jets. Methods. We use the partial Kendall's tau correlation analysis to check the link between radio properties of parsec-scale jets and optical nuclear luminosities of host active galactic nuclei (AGN). Results. We find a significant positive correlation for 99 quasars between optical nuclear luminosities and total radio (VLBA) luminosities of unresolved cores at 15 GHz originated at milliarcseconds scales. For 18 BL Lacs, the optical continuum emission correlates with the radio emission of the jet at 15 GHz. We suggest that the radio and optical emission are beamed and originate in the innermost part of the sub-parsec-scale jet in quasars. Analysis of the relation between the apparent speed of the jet and the optical nuclear luminosity at 5100 Å supports the relativistic beaming model for the optical emission generated in the jet, and allows the peak values of the intrinsic optical luminosity of the jet and its Lorentz factor to be estimated for the populations of quasars (2 × 10 20 W Hz −1 and γ = 52), BL Lacs (9 × 10 21 W Hz −1 and γ = 20), and radio galaxies (1.5 × 10 21 W Hz −1 and γ = 9). The radio-loudness of quasars (the ratio of 15 GHz flux density and optical nuclear flux at 5100 Å) is found to increase at high redshifts, which is interpreted as progressively higher Doppler factors in radio regime compared to those in optical. A strong positive correlation is found between the intrinsic kinetic power of the jet (measured from the flux density at 151 MHz) and the apparent luminosities of the total and the unresolved core emission of the jet at 15 GHz. This correlation is interpreted in terms of an intrinsically more luminous parsec-scale jet producing more luminous extended structure, which is detectable at low radio frequencies, 151 MHz. A possibility that the low frequency radio emission is relativistically beamed in superluminal sources and therefore correlates with radio luminosity of the jet at 15 GHz cannot be ruled out. Monitoring of superluminal AGN in a wide range of frequencies is required to check the contribution of each effect.

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“…Since in ground-based proper-motion determinations the earlier the Ðrst epoch, the better the accuracy, we restrict our Ðrst-epoch observations to this century-old astrographic survey. We did not use the scans of the POSS I plates, which are much deeper than the 14th apparent magnitude limit and can be combined with the present-epoch POSS II survey plates (Humphreys et al 1991 ;Humphreys & Larsen 1995).…”

Section: Diagnosing the Vulpecula Rift From A Photographic Proper-motmentioning

confidence: 99%

Analysis of the Vulpecula Rift from a Photographic Survey of Proper Motions

Fresneau

Monier

1999

The Astronomical Journal

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Photographic proper motions and apparent B and V magnitudes of 5 ] 104 stars in the range m V \ 11 to over the sky area 18h48m ¹ a ¹ 20h04m and 17¡ ¹ d ¹ 25¡ (equinox B1900) are used to m V \ 14 investigate interstellar extinction as distant as 0.8 kpc from the Sun. The Vulpecula molecular cloud, linked to the Vul OB I stellar association, seems conspicuous at a distance of 0.3 kpc with a total extinction of about 1.5 mag, when analyzing 1.6 ] 104 stars with signiÐcant proper-motion components. Transverse velocities for a set of 103 stars along the boundary layer of the molecular cloud suggest a value of 7 ] 102 g cm2 s~1 for the shear viscosity coefficient of the interstellar medium in this region. The characteristic timescale is on the order of 20 Myr, and the free path is on the order of 20 pc. A transfer of optical energy of 2 ] 10~5 yr~1 is indeed suggested from a sample of 400 nebular vari-M _ able candidates at the interface between the suspected gas and dust components. Follow-up spectroscopic observations of three candidates with transverse velocity on the order of 23^14 km s~1 do not rule out the chances of detecting small-scale variations in the interstellar extinction. Key words : dust, extinction È Galaxy : structure È stars : kinematicsThe present study is, in some ways, similar to the work done by Sharpless using photometric observations. He identiÐed the Orion Nebula by selecting stars in front of the nebula and behind it (Sharpless 1952). When stellar proper motions k (in arcsec yr~1) are also available, it is possible to derive a kinematic distance. Since the mean transverse velocity dispersion of disk dwarfs is on the order of 20 km s~1, the nearby stars are segregated from the background stars by a signiÐcant total proper-motion component. The absorbing material can also be located by comparing photometric and kinematic distances (Fresneau 1994). This is di †erent from the analysis of the Wolf diagrams dealing with star counts, because we have an indication of the distance d and an indication of the color excess E(B[V ). The apparent B and V magnitudes are provided by photographic surveys, and the absolute magnitude is M V derived from the reduced proper-motion diagram. Hertzsprung realized indeed (Luyten 1922) that the quantity H \ V ] 5 log k ] 5, where k is the annual proper-motion component (in arcsec yr~1) and V is the apparent magnitude, when plotted versus B[V , is similar to an H-R diagram. Since k \ T /(4.737d) (where the transverse velocity T is in km s~1 and the distance d is in pc), and since the reduced proper motion is (Fresneau 1990). In our study, k and V satisfy 0A .006 yr~1 ¹ yr~1 and 11.0 ¹ V ¹ 14.0. k ¹ 0A .2

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BVR photoelectric sequences for selected fields in the Palomar Sky Survey and the magnitude-diameter relation

Cited by 32 publications

References 1 publication

Stellar photometry with the Carte du Ciel plates

Stellar photometry with the Carte du Ciel plates

Radio-optical scrutiny of compact AGN: correlations between properties of pc-scale jets and optical nuclear emission

Analysis of the Vulpecula Rift from a Photographic Survey of Proper Motions

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