FAINT<i>UBVRI</i>STANDARD STAR FIELDS

Clem, James L.; Landolt, A. U.

doi:10.1088/0004-6256/146/4/88

Cited by 41 publications

(54 citation statements)

References 22 publications

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“…For as definitive a case as possible, with a different instrumental setup, the one-sigma photometric accuracy in measuring a single optimal V-band magnitude is ±0.0144 mag from Landolt (2009 , Table 3), ±0.0069 from Landolt (2013 , Table 4), and ±0.0084 mag from Landolt (1992, Table 2). For a definitive case in measuring the mean errors of a single CCD observation, Clem & Landolt (2013) give 0.0245±0.0159 for the V-band. The Poisson and systematic errors must be added together in quadrature to get the total errors.…”

Section: Photometrymentioning

confidence: 98%

The KIC 8462852 light curve from 2015.75 to 2018.18 shows a variable secular decline

Schaefer

Bentley

Boyajian

et al. 2018

Monthly Notices of the Royal Astronomical Society

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The star KIC 8462852 (Boyajian's Star) displays both fast dips of up to 20% on time scales of days, plus long-term secular fading by up to 19% on time scales from a year to a century. We report on CCD photometry of KIC 8462852 from 2015.75 to 2018.18, with 19,176 images making for 1,866 nightly magnitudes in BVRI. Our light curves show a continuing secular decline (by 0.023±0.003 mags in the B-band) with three superposed dips with duration 120-180 days. This demonstrates that there is a continuum of dip durations from a day to a century, so that the secular fading is seen to be by the same physical mechanism as the short-duration Kepler dips. The BVRI light curves all have the same shape, with the slopes and amplitudes for VRI being systematically smaller than in the B-band by factors of 0.77±0.05, 0.50±0.05, and 0.31±0.05. We rule out any hypothesis involving occultation of the primary star by any star, planet, solid body, or optically thick cloud. But these ratios are the same as that expected for ordinary extinction by dust clouds. This chromatic extinction implies dust particle sizes going down to ∼0.1 micron, suggesting that this dust will be rapidly blown away by stellar radiation pressure, so the dust clouds must have formed within months. The modern infrared observations were taken at a time when there was at least 12.4%±1.3% dust coverage (as part of the secular dimming), and this is consistent with dimming originating in circumstellar dust.

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Section: Photometrymentioning

confidence: 98%

The KIC 8462852 light curve from 2015.75 to 2018.18 shows a variable secular decline

Schaefer

Bentley

Boyajian

et al. 2018

Monthly Notices of the Royal Astronomical Society

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“…The objects were targeted, whenever possible, at different phase angles, aiming at the widest spread possible. Along with the TNOs we targeted several standard star fields each night (from Landolt 1992;and Clem & Landolt 2013), or they were provided by the observatory, as in the case of the Liverpool telescope. We aimed at observing three different fields at three different airmasses per night to cover the range of airmasses of our main targets.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Absolute magnitudes and phase coefficients of trans-Neptunian objects

Álvarez-Candal

Pinilla-Alonso

Ortiz

et al. 2016

A&A

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Context. Accurate measurements of diameters of trans-Neptunian objects (TNOs) are extremely difficult to obtain. Thermal modeling can provide good results, but accurate absolute magnitudes are needed to constrain the thermal models and derive diameters and geometric albedos. The absolute magnitude, H V , is defined as the magnitude of the object reduced to unit helio-and geocentric distances and a zero solar phase angle and is determined using phase curves. Phase coefficients can also be obtained from phase curves. These are related to surface properties, but only few are known. Aims. Our objective is to measure accurate V-band absolute magnitudes and phase coefficients for a sample of TNOs, many of which have been observed and modeled within the program "TNOs are cool", which is one of the Herschel Space Observatory key projects. Methods. We observed 56 objects using the V and R filters. These data, along with those available in the literature, were used to obtain phase curves and measure V-band absolute magnitudes and phase coefficients by assuming a linear trend of the phase curves and considering a magnitude variability that is due to the rotational light-curve. Results. We obtained 237 new magnitudes for the 56 objects, six of which were without previously reported measurements. Including the data from the literature, we report a total of 110 absolute magnitudes with their respective phase coefficients. The average value of H V is 6.39, bracketed by a minimum of 14.60 and a maximum of −1.12. For the phase coefficients we report a median value of 0.10 mag per degree and a very large dispersion, ranging from −0.88 up to 1.35 mag per degree.

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“…Due to this effect, the photometric errors from SExtractor are in general underestimated (see Jeon et al (2010)). We performed photometric calibrations with the standard star catalog near the SEP region from Clem & Landolt (2013). This calibration converts from the instrumental magnitude to the standard Johnson UBV and Kron-Cousins RI systems.…”

Section: Data Reductionmentioning

confidence: 99%

Optical Survey With Kmtnet for Dusty Star-Forming Galaxies in the Akari Deep Field South

Jeong¹,

Ko²,

Kim³

et al. 2016

Journal of The Korean Astronomical Society

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Abstract:We present an optical imaging survey of AKARI Deep Field South (ADF-S) using the Korea Microlensing Telescope Network (KMTNet), to find optical counterparts of dusty star-forming galaxies. The ADF-S is a deep far-infrared imaging survey region with AKARI covering around 12 deg 2 , where the deep optical imaging data are not yet available. By utilizing the wide-field capability of the KMTNet telescopes (∼4 deg 2 ), we obtain optical images in B, R and I bands for three regions. The target depth of images in B, R and I bands is ∼24 mag (AB) at 5σ, which enables us to detect most dusty star-forming galaxies discovered by AKARI in the ADF-S. Those optical datasets will be helpful to constrain optical spectral energy distributions as well as to identify rare types of dusty star-forming galaxies such as dustobscured galaxy, sub-millimeter galaxy at high redshift.

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FAINTUBVRISTANDARD STAR FIELDS

Cited by 41 publications

References 22 publications

The KIC 8462852 light curve from 2015.75 to 2018.18 shows a variable secular decline

The KIC 8462852 light curve from 2015.75 to 2018.18 shows a variable secular decline

Absolute magnitudes and phase coefficients of trans-Neptunian objects

Optical Survey With Kmtnet for Dusty Star-Forming Galaxies in the Akari Deep Field South

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