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1991. Photometric data for SN 2009ip
ID:
ivo://CDS.VizieR/J/ApJ/787/163
Title:
Photometric data for SN 2009ip
Short Name:
J/ApJ/787/163
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present time series photometric and spectroscopic data for the transient SN 2009ip from the start of its outburst in 2012 September until 2013 November. These data were collected primarily with the new robotic capabilities of the Las Cumbres Observatory Global Telescope Network, a specialized facility for time domain astrophysics, and includes supporting high-resolution spectroscopy from the Southern Astrophysical Research Telescope, Kitt Peak National Observatory, and Gemini Observatory. Based on our nightly photometric monitoring, we interpret the strength and timing of fluctuations in the light curve as interactions between fast-moving ejecta and an inhomogeneous circumstellar material (CSM) produced by past eruptions of this massive luminous blue variable (LBV) star. Our time series of spectroscopy in 2012 reveals that, as the continuum and narrow H{alpha} flux from CSM interactions declines, the broad component of H{alpha} persists with supernova (SN)-like velocities that are not typically seen in LBVs or SN impostor events. At late times, we find that SN 2009ip continues to decline slowly, at <~0.01 mag/day, with small fluctuations in slope similar to Type IIn supernovae (SNe IIn) or SN impostors but no further LBV-like activity. The late-time spectrum features broad calcium lines similar to both late-time SNe and SN impostors. In general, we find that the photometric and spectroscopic evolution of SN 2009ip is more similar to SNe IIn than either continued eruptions of an LBV star or SN impostors but we cannot rule out a nonterminal explosion. In this context, we discuss the implications for episodic mass loss during the late stages of massive star evolution.
1992. Photometric histories of recurrent novae
ID:
ivo://CDS.VizieR/J/ApJS/187/275
Title:
Photometric histories of recurrent novae
Short Name:
J/ApJS/187/275
Date:
21 Oct 2021
Publisher:
CDS
Description:
I collect virtually all photometry of the 10 known galactic recurrent novae (RNe) and their 37 known eruptions. This consists of my modern measures of nearly all archival plates (providing the only data for half of 37 known eruptions), my own 10000 CCD magnitudes from 1987 to present (providing virtually all of the magnitudes in quiescence for seven RNe), over 140000 visual magnitude estimates recorded by amateur astronomers (who discovered half the known eruptions), and the small scattering of magnitudes from all the literature. From this, I produce various uniform products: (1) BVRIJHK comparison star magnitudes and BV comparison star sequences to cover the entire range of eruption; (2) complete light curves for all eruptions; (3) best-fit B and V light curve templates; (4) orbital periods for all but one RN; (5) exhaustive searches for all missed eruptions; (6) measured discovery efficiencies since 1890; (7) true recurrence time scales; (8) predicted next eruption dates; (9) variations on time scales of minutes, hours, days, months, years, decades, and century; (10) uniform distances and extinctions to all RNe; (11) BV colors at peak and UBVRIJHK colors at minimum, all with extinction corrections; and (12) the spectral energy distributions over UBVRIJHK. Highlights of this work include the discoveries of one new RN, six previously unknown eruptions, and the orbital periods for half the RNe. The goal of this work is to provide uniform demographics for answering questions like the "What is the death rate of RNe in our Galaxy?" and "Are the white dwarfs gaining or losing mass over each eruption cycle?." An important use of this work is for the question of whether RNe can be the progenitors of Type Ia supernovae.
1993. Photometric identification of BHB stars
ID:
ivo://CDS.VizieR/J/A+A/522/A88
Title:
Photometric identification of BHB stars
Short Name:
J/A+A/522/A88
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the performance of some common machine learning techniques in identifying Blue Horizontal Branch (BHB) stars from photometric data. To train the machine learning algorithms, we use previously published spectroscopic identifications of BHB stars from Sloan Digital Sky Survey (SDSS) data. We investigate the performance of three different techniques, namely k nearest neighbour classification, kernel density estimation for discriminant analysis and a support vector machine (SVM). We discuss the performance of the methods in terms of both completeness (what fraction of input BHB stars are successfully returned as BHB stars) and contamination (what fraction of contaminating sources end up in the output BHB sample). We discuss the prospect of trading off these values, achieving lower contamination at the expense of lower completeness, by adjusting probability thresholds for the classification. We also discuss the role of prior probabilities in the classification performance, and we assess via simulations the reliability of the dataset used for training. Overall it seems that no-prior gives the best completeness, but adopting a prior lowers the contamination. We find that the support vector machine generally delivers the lowest contamination for a given level of completeness, and so is our method of choice. Finally, we classify a large sample of SDSS Data Release 7 (DR7) photometry using the SVM trained on the spectroscopic sample. We identify 27,074 probable BHB stars out of a sample of 294,652 stars. We derive photometric parallaxes and demonstrate that our results are reasonable by comparing to known distances for a selection of globular clusters. We attach our classifications, including probabilities, as an electronic table, so that they can be used either directly as a BHB star catalogue, or as priors to a spectroscopic or other classification method. We also provide our final models so that they can be directly applied to new data.
1994. Photometric masses of early-type lens galaxies
ID:
ivo://CDS.VizieR/J/A+A/501/461
Title:
Photometric masses of early-type lens galaxies
Short Name:
J/A+A/501/461
Date:
21 Oct 2021
Publisher:
CDS
Description:
The largest spectroscopically selected sample of strong gravitational lens systems presented and analyzed to date is that of the Sloan Lens ACS (SLACS) survey. For the 57 massive early-type lens galaxies in the sample, photometric and spectroscopic measurements are available from the Sloan Digital Sky Survey (SDSS). By using the SDSS multicolor photometry and lens modeling, we study stellar-mass properties and the luminous and dark matter composition of the early-type lens galaxies in the sample.
1995. Photometric Measurements, Eggen (102,65,62) System
ID:
ivo://CDS.VizieR/II/18
Title:
Photometric Measurements, Eggen (102,65,62) System
Short Name:
II/18
Date:
21 Oct 2021
Publisher:
CDS
Description:
A catalog of photometric measures in Eggen's (102, 65, 62) system has been compiled at the Institut d'Astronomie de l'Universite de Lausanne. A catalog of individual observations and of weighted means are included, with an explanation of the coded numbering system.
1996. Photometric Measurements in the UBVr 20 System
ID:
ivo://CDS.VizieR/II/15
Title:
Photometric Measurements in the UBVr 20 System
Short Name:
II/15
Date:
21 Oct 2021
Publisher:
CDS
Description:
In the UBVr photometric system defined by Sandage and Smith (1963), (U-B)20, (B-V)20, and (V-r)20 color indices are given for stars from ten reference lists, along with a LID coded number, V magnitude, number of observations and reference. A list of weighted means is included for stars appearing on more than one list. The reference list and an explanation of the coded numbering system are included in separate files.
1997. Photometric metallicities of stars in SkyMapper DR2
ID:
ivo://CDS.VizieR/J/ApJS/254/31
Title:
Photometric metallicities of stars in SkyMapper DR2
Short Name:
J/ApJS/254/31
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Milky Way's metal-poor stars are nearby ancient objects that are used to study early chemical evolution and the assembly and structure of the Milky Way. Here we present reliable metallicities of ~280000 stars with -3.75<~[Fe/H]<~-0.75 down to g=17 derived using metallicity-sensitive photometry from the second data release of the SkyMapper Southern Survey. We use the dependency of the flux through the SkyMapper v filter on the strength of the CaII K absorption features, in tandem with SkyMapper u, g, i photometry, to derive photometric metallicities for these stars. We find that metallicities derived in this way compare well to metallicities derived in large-scale spectroscopic surveys, and we use such comparisons to calibrate and quantify systematics as a function of location, reddening, and color. We find good agreement with metallicities from the APOGEE, LAMOST, and GALAH surveys, based on a standard deviation of {sigma}~0.25dex of the residuals of our photometric metallicities with respect to metallicities from those surveys. We also compare our derived photometric metallicities to metallicities presented in a number of high-resolution spectroscopic studies to validate the low-metallicity end ([Fe/H]{<}-2.5) of our photometric metallicity determinations. In such comparisons, we find the metallicities of stars with photometric [Fe/H]{<}-2.5 in our catalog show no significant offset and a scatter of {sigma}~0.31dex level relative to those in high-resolution work when considering the cooler stars (g-i>0.65) in our sample. We also present an expanded catalog containing photometric metallicities of ~720000 stars as a data table for further exploration of the metal-poor Milky Way.
1998. Photometric monitoring of 47 late-type stars
ID:
ivo://CDS.VizieR/J/A+AS/140/29
Title:
Photometric monitoring of 47 late-type stars
Short Name:
J/A+AS/140/29
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present continuous multicolor photometry for 47 stars from October 1996 through June 1997. Altogether, 7073 V(RI)_c_, UBV, and by data points, each the average of three individual readings, were acquired with three automatic photoelectric telescopes (APTs) at Fairborn Observatory in southern Arizona. Most of our targets are chromospherically active single and binary stars of spectral type G to K but there are also four pre-main-sequence objects and three pulsating stars in our sample. The light variability is generally due to rotational modulation of an asymmetrically spotted stellar surface and therefore precise rotational periods and their seasonal variations are determined from Fourier analysis. We also report on photometric variations of {gamma} CrB (A0V) with a period of 0.44534 days. All data are available in numerical form.
1999. Photometric obs. & LAMOST sp. of 4 W UMa binaries
ID:
ivo://CDS.VizieR/J/ApJ/901/169
Title:
Photometric obs. & LAMOST sp. of 4 W UMa binaries
Short Name:
J/ApJ/901/169
Date:
22 Feb 2022 00:36:07
Publisher:
CDS
Description:
We present new photometric data and LAMOST spectra for the W UMa binaries UV Lyn, V781 Tau, NSVS 4484038, and 2MASS J15471055+5302107. The orbital and starspot parameters are obtained using the Wilson-Devinney program. Comparing the starspot parameters at different times, there are magnetic activities in these four binaries. The orbital period of UV Lyn is increasing at a rate of dP/dt=+8.9(5)x10^-8^d/yr, which maybe due to mass transfer from the less massive component to the more massive component (dM1/dt=-6.4x10^-8^M_{sun}_/yr). The period variation of 2MASSJ15471055+5302107 is also increasing at a rate of 6.0(4)x10^-7^d/yr, which can be explained by mass transfer from the less massive component to the more massive component (dM1/dt=-2.8x10^-7^M_{sun}_/yr). The period variation of V781 Tau presents the downward parabola superimposed the cyclic oscillation. The period of V781 Tau is decreasing (dP/dt=-3.2(4)x10^-8^d/yr), which can be explained by mass transfer from the more massive component to the less massive component (dM2/dt=-2.2x10^-8^M_{sun}_/yr). The cyclic oscillation may be due to the magnetic activity with a period of 30.8(5)yr rather than a third body. The period variation of NSVS4484038 also shows the cyclic oscillation, which could be explained by the magnetic activity with 10.8(1)yr or a black hole candidate. Interestingly, there is a depth variation between the light minimum times of NSVS 4484038, which may also be caused by stellar magnetic activity.
2000. Photometric profiles from GOODS data
ID:
ivo://CDS.VizieR/J/ApJ/684/1026
Title:
Photometric profiles from GOODS data
Short Name:
J/ApJ/684/1026
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have conducted the largest systematic search so far for stellar disk truncations in disklike galaxies at intermediate redshift (z<1.1), using the Great Observatories Origins Deep Survey-South (GOODS-S) data from the Hubble Space Telescope ACS. Focusing on type II galaxies (i.e., downbending profiles), we explore whether the position of the break in the rest-frame B-band radial surface brightness profile (a direct estimator of the extent of the disk where most of the massive star formation is taking place) evolves with time. The number of galaxies under analysis (238 of a total of 505) is an order of magnitude larger than in previous studies. For the first time, we probe the evolution of the break radius for a given stellar mass (a parameter well suited to address evolutionary studies). We have explored the distribution of the scale lengths of the disks in the region inside the break and how this parameter relates to the break radius. We also present results of the statistical analysis of profiles of artificial galaxies, to assess the reliability of our results.