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3341. Smoothed amplitudes from Kepler, K2 and TESS phot.
ID:
ivo://CDS.VizieR/J/ApJ/893/67
Title:
Smoothed amplitudes from Kepler, K2 and TESS phot.
Short Name:
J/ApJ/893/67
Date:
03 Dec 2021 00:35:27
Publisher:
CDS
Description:
We investigate starspot distributions consistent with space-based photometry of F, G, and K stars in six stellar associations ranging in age from 10Myr to 4Gyr. We show that a simple light-curve statistic called the "smoothed amplitude" is proportional to stellar age as t^-1/2^, following a Skumanich-like spin-down relation. We marginalize over the unknown stellar inclinations by forward modeling the ensemble of light curves for direct comparison with the Kepler, K2, and TESS photometry. We sample the posterior distributions for spot coverage with approximate Bayesian computation. We find typical spot coverages in the range 1%-10%, which decrease with increasing stellar age. The spot coverage is proportional to t^n^ where n=-0.37+/-0.16, also statistically consistent with a Skumanich-like t^-1/2^ decay of starspot coverage with age. We apply two techniques to estimate the spot coverage of young exoplanet-hosting stars likely to be targeted for transmission spectroscopy with the James Webb Space Telescope, and estimate the bias in exoplanet radius measurements due to varying starspot coverage.
3342. SMUDGes. I. First results in the Coma Cluster
ID:
ivo://CDS.VizieR/J/ApJS/240/1
Title:
SMUDGes. I. First results in the Coma Cluster
Short Name:
J/ApJS/240/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a homogeneous catalog of 275 large (effective radius >~5.3") ultra-diffuse galaxy (UDG) candidates lying within an ~290deg^2^ region surrounding the Coma Cluster. The catalog results from our automated postprocessing of data from the Legacy Surveys, a three-band imaging survey covering 14000deg^2^ of the extragalactic sky. We describe a pipeline that identifies UDGs and provides their basic parameters. The survey is as complete in these large UDGs as previously published UDG surveys of the central region of the Coma Cluster. We conclude that the majority of our detections are at roughly the distance of the Coma Cluster, implying effective radii >=2.5kpc, and that our sample contains a significant number of analogs of DF44 (SMDG1300580+265835), where the effective radius exceeds 4kpc, both within the cluster and in the surrounding field. The g-z color of our UDGs spans a large range, suggesting that even large UDGs may reflect a range of formation histories. A majority of the UDGs are consistent with being lower stellar mass analogs of red sequence galaxies, but we find both red and blue UDG candidates in the vicinity of the Coma Cluster and a relative overabundance of blue UDG candidates in the lower-density environments and the field. Our eventual processing of the full Legacy Surveys data will produce the largest, most homogeneous sample of large UDGs.
3343. SN 2008ax UBVRI light curves
ID:
ivo://CDS.VizieR/J/other/PZ/29.2
Title:
SN 2008ax UBVRI light curves
Short Name:
J/other/PZ/29.2
Date:
21 Oct 2021
Publisher:
CDS
Description:
CCD UBVRI photometry covering about 320 days is presented for the type IIb SN 2008ax. Its photometric behavior is typical of core-collapse SNe with low amount of hydrogen. The main photometric parameters are derived and a comparison with SNe of similar types is reported. Preliminary modeling is carried out, and the results are compared to the observed light curves. The main parameters of the hydrodynamical models are close to those used for SN IIb 1993J.
3344. SN 2020bqj ligth curves
ID:
ivo://CDS.VizieR/J/A+A/652/A136
Title:
SN 2020bqj ligth curves
Short Name:
J/A+A/652/A136
Date:
22 Feb 2022
Publisher:
CDS
Description:
Type Ibn supernovae are a rare class of stripped envelope supernovae interacting with a helium-rich CSM. The majority of the SNe Ibn reported display a surprising homogeneity in their fast lightcurves and starforming hosts. We present the discovery and study of SN 2020bqj (ZTF20aalrqbu), a SN Ibn with a long-duration peak plateau lasting 40 days and hosted by a faint low-mass galaxy. We aim to explain its peculiar properties using an extensive data set. We compare the evolution of SN 2020bqj with SNe Ibn from the literature. We fit the bolometric and multi-band lightcurves with different powering mechanism models. The risetime, peak magnitude and spectral features of SN 2020bqj are consistent with those of most SNe Ibn, but the SN is a clear outlier based on its bright, long-lasting peak plateau and low host mass. We show through modeling that the lightcurve can be powered predominantly by shock heating from the interaction of the SN ejecta and a dense CSM. The peculiar Type Ibn SN 2011hw is a close analog to SN 2020bqj, suggesting a similar progenitor and CSM scenario. In this scenario a very massive progenitor star in the transitional phase between a luminous blue variable and a compact Wolf-Rayet star undergoes core-collapse, embedded in a dense helium-rich CSM with an elevated opacity compared to normal SNe Ibn, due to the presence of residual hydrogen. This scenario is consistent with the observed properties of SN 2020bqj and the modeling results. SN 2020bqj is a compelling example of a transitional SN Ibn/IIn based on not only its spectral features, but also its lightcurve, host galaxy properties and the inferred progenitor properties. The strong similarity with SN 2011hw suggests this subclass may be the result of a progenitor in a stellar evolution phase that is distinct from those of progenitors of regular SNe Ibn.
3345. SN 2020bvc optical and near-IR spectra
ID:
ivo://CDS.VizieR/J/ApJ/908/232
Title:
SN 2020bvc optical and near-IR spectra
Short Name:
J/ApJ/908/232
Date:
11 Mar 2022
Publisher:
CDS
Description:
We present near-IR (NIR) and optical observations of the Type Ic supernova (SN Ic) SN 2020oi in the galaxy M100 and the broad-lined SN Ic SN 2020bvc in UGC 9379, using Gemini, Las Cumbres Observatory, Southern Astrophysical Telescope, and other ground-based telescopes. The NIR spectrum of SN 2020oi at day 63 since the explosion shows strong CO emissions and a rising K-band continuum, which is the first unambiguous dust detection from an SN Ic. Non-LTE CO modeling shows that CO is still optically thick and that the lower limit to the CO mass is 10^-3^M_{sun}_. The dust temperature is 810 K, and the dust mass is ~10^-5^M_{sun}_. We explore the possibilities that the dust is freshly formed in the ejecta, heated dust in the preexisting circumstellar medium, and an infrared echo. The light curves of SN 2020oi are consistent with a STELLA model with canonical explosion energy, 0.07M_{sun}_ Ni mass, and 0.7M_{sun}_ ejecta mass. A model of high explosion energy of 10^52^erg, 0.4M_{sun}_ Ni mass, and 6.5M_{sun}_ ejecta mass with the circumstellar matter reproduces the double-peaked light curves of SN 2020bvc. We observe temporal changes of absorption features of the IR CaII triplet, SI at 1.043{mu}m, and FeII at 5169{AA}. The blueshifted lines indicate high velocities, up to 60000km/s for SN 2020bvc and 20000km/s for SN 2020oi, and the expansion velocity rapidly declines before the optical maximum. We present modeled spectral signatures and diagnostics of CO and SiO molecular bands between 1.4 and 10{mu}m.
3346. SN 2005cs one-year photometry
ID:
ivo://CDS.VizieR/J/MNRAS/394/2266
Title:
SN 2005cs one-year photometry
Short Name:
J/MNRAS/394/2266
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of the one-year long observational campaign of the type II plateau SN 2005cs, which exploded in the nearby spiral galaxy M51 (the Whirlpool galaxy). This extensive data set makes SN 2005cs the best observed low-luminosity, ^56^Ni-poor type II plateau event so far and one of the best core-collapse supernovae ever.
3347. SN 2020cxd multi-photometry
ID:
ivo://CDS.VizieR/J/A+A/655/A90
Title:
SN 2020cxd multi-photometry
Short Name:
J/A+A/655/A90
Date:
22 Feb 2022
Publisher:
CDS
Description:
We present observations and analysis of SN 2020cxd, a low-luminosity (LL), long-lived Type IIP supernova (SN). This object was a clear outlier in the magnitude-limited SN sample recently presented by the Zwicky Transient Facility (ZTF) Bright Transient Survey. We demonstrate that SN 2020cxd is an additional member of the group of LL SNe, and discuss the rarity of LL SNe in the context of the ZTF survey, and how further studies of these faintest members of the core-collapse (CC) SN family might help understand the underlying initial mass function for stars that explode. We present optical light curves (LCs) from the ZTF in the $gri$ bands and several epochs of ultra-violet data from the Neil Gehrels Swift Observatory as well as a sequence of optical spectra. We construct colour curves, a bolometric LC, compare ejecta-velocity and black-body temperature evolutions for LL SNe, as well as for typical Type II SNe. Furthermore, we adopt a Monte Carlo code that fits semi-analytic models to the LC of SN 2020cxd, which allows the estimation of physical parameters. Using our late-time nebular spectra, we also compare against SN II spectral synthesis models from the literature to constrain the progenitor properties of SN 2020cxd. The LCs of SN 2020cxd show great similarity with those of LL SNe IIP, in luminosity, timescale and colours. Also the spectral evolution of SN 2020cxd is that of a Type IIP SN. The spectra show prominent and narrow P-Cygni lines, indicating low expansion velocities. This is one of the faintest LL SNe observed, with an absolute plateau magnitude of M_r_=-14.5mag, and also one with the longest plateau lengths, with a duration of 118 days. Finally, the velocities measured from the nebular emission lines are among the lowest ever seen in a SN, with intrinsic Full Width at Half Maximum of 478km/s. The underluminous late-time exponential LC tail indicates that the mass of ^56^Ni ejected during the explosion is much smaller than the average of normal SNe IIP, we estimate M_^56^Ni_=0.003M+{sun+_. The Monte Carlo fitting of the bolometric LC suggests that the progenitor of SN 2020cxd had a radius of R_0_=1.3x10^13^cm, kinetic energy of E_kin_=4.3x10^50^erg, and ejecta mass M_ej_=9.5M_{sun}_. From the bolometric LC, we estimate the total radiated energy E_rad_=1.52x10^48^erg. Using our late-time nebular spectra, we compare against SN II spectral synthesis models to constrain the progenitor Zero-age Main-sequence mass and found it likely to be <~15M_{sun}+. SN 2020cxd is a LL Type IIP SN. The inferred progenitor parameters and the features observed in the nebular spectrum favour a low-energy, Ni-poor, iron CC SN from a low mass ~12M_{sun}_ red supergiant.
3348. SN 2011dh - The first 100 days
ID:
ivo://CDS.VizieR/J/A+A/562/A17
Title:
SN 2011dh - The first 100 days
Short Name:
J/A+A/562/A17
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present optical and near-infrared (NIR) photometry and spectroscopy of the Type IIb supernova (SN) 2011dh for the first 100 days. We complement our extensive dataset with Swift ultra-violet (UV) and Spitzer mid-infrared (MIR) data to build a UV to MIR bolometric lightcurve using both photometric and spectroscopic data. Hydrodynamical modelling of the SN based on this bolometric lightcurve have been presented in Bersten et al. (2012ApJ...757...31B).
3349. SN 2011dh. The first two years
ID:
ivo://CDS.VizieR/J/A+A/580/A142
Title:
SN 2011dh. The first two years
Short Name:
J/A+A/580/A142
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present optical and near-infrared (NIR) photometry and spectroscopy as well as modelling of the lightcurves of the Type IIb supernova (SN) 2011dh. Our extensive dataset, for which we present the observations obtained after day 100, spans two years, and complemented with Spitzer mid-infrared (MIR) data, we use it to build an optical-to-MIR bolometric lightcurve between days 3 and 732.
3350. SN 2004dj UBVRI light curves
ID:
ivo://CDS.VizieR/J/other/PZ/28.8
Title:
SN 2004dj UBVRI light curves
Short Name:
J/other/PZ/28.8
Date:
21 Oct 2021
Publisher:
CDS
Description:
CCD UBVRI photometry is presented for type II SN 2004dj for about 1200 days, starting on day 2 past discovery. The photometric behaviour is typical of SNe II-P, although some minor peculiarities are noticed. We compare the photometric data for the host cluster S96 before and after the SN 2004dj outburst and do not find any significant changes.