Search

Start Over Subject spectroscopy
2961. Type IIP SN 2016bkv LCs and spectra
ID:
ivo://CDS.VizieR/J/ApJ/861/63
Title:
Type IIP SN 2016bkv LCs and spectra
Short Name:
J/ApJ/861/63
Date:
21 Oct 2021
Publisher:
CDS
Description:
While interaction with circumstellar material is known to play an important role in Type IIn supernovae (SNe), analyses of the more common SNe IIP and IIL have not traditionally included interaction as a significant power source. However, recent campaigns to observe SNe within days of explosion have revealed narrow emission lines of high-ionization species in the earliest spectra of luminous SNe II of all subclasses. These "flash ionization" features indicate the presence of a confined shell of material around the progenitor star. Here we present the first low-luminosity (LL) SN to show flash ionization features, SN 2016bkv. This SN peaked at MV = -16 mag and has H{alpha} expansion velocities under 1350 km s-1 around maximum light, placing it at the faint/slow end of the distribution of SNe IIP (similar to SN 2005cs). The light-curve shape of SN 2016bkv is also extreme among SNe IIP. A very strong initial peak could indicate additional luminosity from circumstellar interaction. A very small fall from the plateau to the nickel tail indicates unusually large production of radioactive nickel compared to other LL SNe IIP. A comparison between nebular spectra of SN 2016bkv and models raises the possibility that SN 2016bkv is an electron-capture supernova.
2962. Type IIP supernovae from Pan-STARRS1
ID:
ivo://CDS.VizieR/J/ApJ/799/208
Title:
Type IIP supernovae from Pan-STARRS1
Short Name:
J/ApJ/799/208
Date:
21 Oct 2021
Publisher:
CDS
Description:
In recent years, wide-field sky surveys providing deep multiband imaging have presented a new path for indirectly characterizing the progenitor populations of core-collapse supernovae (SNe): systematic light-curve studies. We assemble a set of 76 grizy-band Type IIP SN light curves from Pan-STARRS1, obtained over a constant survey program of 4yr and classified using both spectroscopy and machine-learning-based photometric techniques. We develop and apply a new Bayesian model for the full multiband evolution of each light curve in the sample. We find no evidence of a subpopulation of fast-declining explosions (historically referred to as "Type IIL" SNe). However, we identify a highly significant relation between the plateau phase decay rate and peak luminosity among our SNe IIP. These results argue in favor of a single parameter, likely determined by initial stellar mass, predominantly controlling the explosions of red supergiants. This relation could also be applied for SN cosmology, offering a standardizable candle good to an intrinsic scatter of <~0.2mag. We compare each light curve to physical models from hydrodynamic simulations to estimate progenitor initial masses and other properties of the Pan-STARRS1 Type IIP SN sample. We show that correction of systematic discrepancies between modeled and observed SN IIP light-curve properties and an expanded grid of progenitor properties are needed to enable robust progenitor inferences from multiband light-curve samples of this kind. This work will serve as a pathfinder for photometric studies of core-collapse SNe to be conducted through future wide-field transient searches.
2963. UBV and line identification of V1853 Cyg
ID:
ivo://CDS.VizieR/J/PAZh/27/841
Title:
UBV and line identification of V1853 Cyg
Short Name:
J/PAZh/27/841
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photoelectric and spectroscopic observations of the protoplanetary object V1853 Cyg, a B supergiant with an IR excess, are given. The observations were carried out with a UBV photometer attached to the 60-cm Zeiss telescope at the Crimean Station of the Stenberg Astronomical Institute.
2964. UBV and spectroscopic variations of V2368 Oph
ID:
ivo://CDS.VizieR/J/A+A/531/A49
Title:
UBV and spectroscopic variations of V2368 Oph
Short Name:
J/A+A/531/A49
Date:
21 Oct 2021
Publisher:
CDS
Description:
The A-type star HR 6412 = V2368 Oph was used by several investigators as a photometric comparison star for the known eclipsing binary U Oph but was found to be variable by three independent groups, including us. By analysing series of new spectral and photometric observations and a critical compilation of available radial velocities, we were able to find the correct period of light and radial-velocity variations and demonstrate that the object is an eclipsing and double-lined spectroscopic binary moving in a highly eccentric orbit. We derived a linear ephemeris Tmin.I=HJD(2454294.67+/-0.01)+(38.32712+/-0.00004)d*E and estimated preliminary basic physical properties of the binary.
2965. UBV light curve and spectroscopy of StHa62
ID:
ivo://CDS.VizieR/J/PAZh/32/737
Title:
UBV light curve and spectroscopy of StHa62
Short Name:
J/PAZh/32/737
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photoelectric observations of HD 51585 (OY Gem), a B[e] star with an infrared excess and a candidate for protoplanetary nebulae, obtained with a 60-cm telescope at the Crimean Station of Sternberg Astronomical Institute in 1992-2005 are presented. The star exhibited rapid irregular brightness variations with amplitudes from 0.1mag in the V band to 0.2mag in the U band within the observing season as well as slow systematic variations. with a quasi-period of ~2800-days. Low-resolution spectroscopy performed in 1994-2005 has revealed significant variability of the Balmer and Paschen hydrogen emission lines as well as the HeI and OI lines. Equivalent widths are given for the HI, HeI, OI, and FeII lines. Correlation has been found between the star's photometric variability and the hydrogen line intensities.
2966. UBV photometry of IRAS 18062+2410
ID:
ivo://CDS.VizieR/J/PAZh/25/30
Title:
UBV photometry of IRAS 18062+2410
Short Name:
J/PAZh/25/30
Date:
21 Oct 2021
Publisher:
CDS
Description:
The photometric and spectroscopic observations of IRAS 18062+2410 = V886 Her, a candidate for protoplanetary objects, in 1996-1997 are presented. The star exhibits rapid light variations with an amplitude up to 0.3mag in V. A high-resolution spectrum of IRAS shows absorption lines of H, HeI, OI, FeII, SiII, NaI and other species, including [OII], [NII], and [FeII] that belong to the stellar envelope.
2967. UBVR and spectroscopic observations of CI Cam
ID:
ivo://CDS.VizieR/J/AZh/79/309
Title:
UBVR and spectroscopic observations of CI Cam
Short Name:
J/AZh/79/309
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photoelectric (UBVR) observations in 1998-2001 and medium-resolution spectroscopy obtained in the SAO in the same period for the B[e]/X-ray transient CI Cam display cyclic variations with a period of 1100 days.
2968. UBV(RI)c photometry of stars around V838 Mon
ID:
ivo://CDS.VizieR/J/A+A/434/1107
Title:
UBV(RI)c photometry of stars around V838 Mon
Short Name:
J/A+A/434/1107
Date:
21 Oct 2021
Publisher:
CDS
Description:
Extensive optical and infrared photometry as well as low and high resolution spectroscopy are used as inputs in deriving robust estimates of the reddening, distance and nature of the progenitor of V838 Mon, the 2002 outbursting event that produced a most spectacular light-echo.
2969. UBVRIJHK & spec. obs. of type Ia SN2019ein
ID:
ivo://CDS.VizieR/J/ApJ/893/143
Title:
UBVRIJHK & spec. obs. of type Ia SN2019ein
Short Name:
J/ApJ/893/143
Date:
07 Mar 2022 07:30:20
Publisher:
CDS
Description:
We present optical observations of the Type Ia supernova (SN) 2019ein, starting two days after the estimated explosion date. The spectra and light curves show that SN 2019ein belongs to a high-velocity (HV) and broad-line group with a relatively rapid decline in the light curves ({Delta}m_15_(B)=1.36+/-0.02mag) and a short rise time (15.37+/-0.55days). The SiII{lambda}6355 velocity, associated with a photospheric component but not with a detached high-velocity feature, reached ~20000km/s 12 days before the B-band maximum. The line velocity, however, decreased very rapidly and smoothly toward maximum light, to ~13000km/s, which is relatively low among HV SNe. This indicates that the speed of the spectral evolution of HV SNe Ia is correlated with not only the velocity at maximum light, but also the light-curve decline rate, as is the case for normal-velocity (NV) SNeIa. Spectral synthesis modeling shows that the outermost layer at >17000km/s is well described by an O-Ne-C burning layer extending to at least 25000km/s, and there is no unburnt carbon below 30000km/s; these properties are largely consistent with the delayed detonation scenario and are shared with the prototypical HV SN 2002bo despite the large difference in {Delta}m_15_(B). This structure is strikingly different from that derived for the well-studied NV SN 2011fe. We suggest that the relation between the mass of ^56^Ni (or {Delta}m_15_) and the extent of the O-Ne-C burning layer provides an important constraint on the explosion mechanism(s) of HV and NV SNe.
2970. UBVRI photometry and line fluxes of AG Peg
ID:
ivo://CDS.VizieR/J/A+A/604/A48
Title:
UBVRI photometry and line fluxes of AG Peg
Short Name:
J/A+A/604/A48
Date:
21 Oct 2021
Publisher:
CDS
Description:
AG Peg is known as the slowest symbiotic nova, which experienced its nova-like outburst around 1850. After 165 years, during June of 2015, it erupted again showing characteristics of the Z And-type outburst. The primary objective is to determine basic characteristics, the nature and type of the 2015 outburst of AG Peg. We achieved this aim by modelling the spectral energy distribution using low-resolution spectroscopy (330-750nm), medium-resolution spectroscopy (420-720nm; R=11000), and UBVR_C_I_C_ photometry covering the 2015 outburst with a high cadence. Optical observations were complemented with the archival HST and FUSE spectra from the preceding quiescence. During the outburst, the luminosity of the hot component was in the range of 2-11x10^37^(d/0.8kpc})^2^erg/s. To generate the maximum luminosity the white dwarf (WD) had to accrete at ~3x10^-7^M_{sun}/yr, which exceeds the stable-burning limit and thus led to blowing optically thick wind from the WD. We determined its mass-loss rate to a few x10^-6^M_{sun}/yr. At the high temperature of the ionising source, 1.5-2.3x10^5^K, the wind converted a fraction of the WD's photospheric radiation into the nebular emission that dominated the optical. A one order of magnitude increase of the emission measure, from a few x10^59^(d/0.8kpc)^2^/cm^3^ during quiescence, to a few x10^60^(d/0.8kpc)^2^/cm^3^ during the outburst, caused a 2mag brightening in the LC, which is classified as the Z And-type of the outburst. The very high nebular emission and the presence of a disk-like HI region encompassing the WD, as indicated by a significant broadening and high flux of the Raman-scattered OVI 6825{AA} line during the outburst, is consistent with the ionisation structure of hot components in symbiotic stars during active phases.

Limit your search

more »

more »

more »

more »

more »