- ID:
- ivo://CDS.VizieR/J/PAZh/25/893
- Title:
- Optical outbursts of the blazar 3C 345
- Short Name:
- J/PAZh/25/893
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photographic UBV photometry of the blazar 3C 345 that were made during 79 nights in 1971-1974 and 1983-1984 as a part of the Petersburg Quasar Monitoring Program (PQMP) carried out at the Astronomical Institute of the St.-Petersburg University. These data were previously published by piecemeal (references are presented in Section 4). Now after partial revision these data are united in Table 1 that presents nightly averaged UBV magnitudes together with its rms errors (see Section 4 of the paper for the details). These data were used for the comparison of the spectral indices of the emission in the "fast" (time scales of nearly 10-20 days) and "slow" (time scales of nearly 1 yeas) outbursts in 3C 345.
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- ID:
- ivo://CDS.VizieR/J/AJ/155/90
- Title:
- 1996-2009 optical photometric monitoring for 3C 66A
- Short Name:
- J/AJ/155/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 3C 66A is one of the most interesting blazars and one of our monitoring objects carried out with the 1.56 m telescope at Sheshan station, Shanghai Astronomical Observatory (ShAO). It has been monitored since 1996 December 11. In the present work, we show its optical light curves during the period of 1996 December 11-2009 December 28. From our observations, we found that the largest variations in the V, R, and I bands are {Delta}V=1.840+/-0.065, {Delta}R=1.898+/-0.069 mag, and {Delta}I=1.659+/-0.047 mag, respectively. Intra-day variabilities are found in the three bands: in the V band, an A=17.7% brightness increase over {Delta}T=47.5 minutes on JD 2455119, and an A=46.27% brightness increase over {Delta}T=271.4 minutes on JD 2454816; in the R band, an A=47.09% brightness increase over {Delta}T=23.18 minutes on JD 2454004, and an A=38.11% brightness increase over {Delta}T=87.98 minutes on JD 2453995; and in the I band, an A=13.2% brightness decrease over {Delta}T=38.44 minutes on JD 2453995, and an A=92.8% brightness decrease over {Delta}T=344.02 minutes on JD 2454818. For micro-variability, we found that R variability leads I variability by 25.92+/-1.09 minutes. When the periodicity analysis methods, with the red noise being considered, are adopted to the V, R, and I observations, we can find that the periodogram to the V data is consistent with red noise, except for 1 CLEANest peak corresponding to the timescale of 696.0+/-182.0 days, those to the R data are 653.0+/-171.0 and 156.0+/-17.0 days; and those to the I data are 801.0+/-207.0 and 156.0+/-15.0 days, respectively.
- ID:
- ivo://CDS.VizieR/J/AJ/160/235
- Title:
- Optical photometry and RVs of TOI-481b and TOI-892b
- Short Name:
- J/AJ/160/235
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of two new 10 day period giant planets from the Transiting Exoplanet Survey Satellite mission, whose masses were precisely determined using a wide diversity of ground-based facilities. TOI-481b and TOI-892b have similar radii (0.99{+/-}0.01R_Jup_ and 1.07{+/-}0.02R_Jup_, respectively), and orbital periods (10.3311days and 10.6266days, respectively), but significantly different masses (1.53{+/-}0.03M_Jup versus 0.95{+/-}0.07M_Jup_, respectively). Both planets orbit metal-rich stars ([Fe/H]=+0.26{+/-}0.05dex and [Fe/H]=+0.24{+/-}0.05 for TOI-481 and TOI-892, respectively) but at different evolutionary stages. TOI-481 is a M_*_=1.14{+/-}0.02M_{odot}_, R_*_=1.66{+/-}0.02R_{odot}_ G-type star (Teff=5735{+/-}72K), that with an age of 6.7Gyr, is in the turn-off point of the main sequence. TOI-892 on the other hand, is a F-type dwarf star (Teff=6261{+/-}80K), which has a mass of M_*_=1.28{+/-}0.03M_{odot}_ and a radius of R_*_=1.39{+/-}0.02R_{odot}_. TOI-481b and TOI-892b join the scarcely populated region of transiting gas giants with orbital periods longer than 10days, which is important to constrain theories of the formation and structure of hot Jupiters.
- ID:
- ivo://CDS.VizieR/J/AJ/150/67
- Title:
- Optical photometry for 1ES 1959+650
- Short Name:
- J/AJ/150/67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the 1.56m telescope at Shanghai Observatory, China, we present the photometric results of 1ES 1959+650, which cover from 2006 June 11 to 2014 July 31. The maximum variabilities are {Delta}m_V|max_=1.74+/-0.02mag in the V band, {Delta}m_R|max_=0.97+/-0.02mag in the R band, and {Delta}m_I/max_=1.15+/-0.03mag in the I band. During the monitoring period, we obtain intraday variabilities on 2009 September 2 (JD2455077) and 2009 September 3 (JD2455078). On 2009 September 2, the intraday variabilities are {Delta}m_V_=0.36+/-0.08mag within 1.56hr, {Delta}m_R_=0.21+/-0.04mag within 23minutes, and {Delta}m_I_=0.53+/-0.03mag within 45minutes. On 2009 September 3, the intraday variabilities are {Delta}m_V_=0.40+/-0.10mag within 27minutes, {Delta}m_R_=0.48+/-0.04mag within 3.24hr, and {Delta}m_I_=0.68+/-0.06mag within 3.72hr. The two intraday variabilities occur in 24hr, which may occur in the same variable phase. Other results show that (1) no quasi-periodicity is found in the long-term light curve and (2) the correlations between the brightness and the spectrum show obvious anti-correlation, {alpha}=-(0.18+/-0.02)F_V_+(2.33+/-0.12), with the correlation coefficient r=-0.74 and the chance probability p<0.01%.
- ID:
- ivo://CDS.VizieR/J/ApJ/756/79
- Title:
- Optical photometry in 3 Local Group dwarf galaxies
- Short Name:
- J/ApJ/756/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep wide-field photometry of three recently discovered faint Milky Way (MW) satellites: Leo V, Pisces II, and Canes Venatici II. Our main goals are to study the structure and star formation history of these dwarfs; we also search for signs of tidal disturbance. The three satellites have similar half-light radii (~60-90pc) but a wide range of ellipticities. Both Leo V and CVn II show hints of stream-like overdensities at large radii. An analysis of the satellite color-magnitude diagrams shows that all three objects are old (>10Gyr) and metal-poor ([Fe/H]~-2), though neither the models nor the data have sufficient precision to assess when the satellites formed with respect to cosmic reionization. The lack of an observed younger stellar population (<~10Gyr) possibly sets them apart from the other satellites at Galactocentric distances >~150kpc. We present a new compilation of structural data for all MW satellite galaxies and use it to compare the properties of classical dwarfs to the ultra-faints. The ellipticity distribution of the two groups is consistent at the ~2{sigma} level. However, the faintest satellites tend to be more aligned toward the Galactic Center, and those satellites with the highest ellipticity (>~0.4) have orientations ({Delta}{theta}_GC_) in the range 20{deg}<~{Delta}{theta}_GC_<~40{deg}. This latter observation is in rough agreement with predictions from simulations of dwarf galaxies that have lost a significant fraction of their dark matter halos and are being tidally stripped.
- ID:
- ivo://CDS.VizieR/J/ApJ/769/108
- Title:
- Optical photometry of 4 millisecond pulsars
- Short Name:
- J/ApJ/769/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the last few years, over 43 millisecond radio pulsars have been discovered by targeted searches of unidentified {gamma}-ray sources found by the Fermi Gamma-Ray Space Telescope. A large fraction of these millisecond pulsars are in compact binaries with low-mass companions. These systems often show eclipses of the pulsar signal and are commonly known as black widows and redbacks because the pulsar is gradually destroying its companion. In this paper, we report on the optical discovery of four strongly irradiated millisecond pulsar companions. All four sources show modulations of their color and luminosity at the known orbital periods from radio timing. Light curve modeling of our exploratory data shows that the equilibrium temperature reached on the companion's dayside with respect to their nightside is consistent with about 10%-30% of the available spin-down energy from the pulsar being reprocessed to increase the companion's dayside temperature. This value compares well with the range observed in other irradiated pulsar binaries and offers insights about the energetics of the pulsar wind and the production of {gamma}-ray emission. In addition, this provides a simple way of estimating the brightness of irradiated pulsar companions given the pulsar spin-down luminosity. Our analysis also suggests that two of the four new irradiated pulsar companions are only partially filling their Roche lobe. Some of these sources are relatively bright and represent good targets for spectroscopic follow-up.
- ID:
- ivo://CDS.VizieR/J/MNRAS/447/1661
- Title:
- Optical photometry of nova V5588 Sgr
- Short Name:
- J/MNRAS/447/1661
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The outburst of Nova Sgr 2011 N.2 (=V5588 Sgr) was followed with optical and near-IR photometric and spectroscopic observations for 3.5 yr, beginning shortly before the maximum. V5588 Sgr is located close to Galactic Centre, suffering from E(B-V)=1.56(+/-0.1) extinction. The primary maximum was reached at V=12.37 on UT 2011 April 2.5(+/-0.2), and the underlying smooth decline was moderately fast with t^V^_2_=38 and t^V^_3_=77 d. On top of an otherwise normal decline, six self-similar, fast evolving and bright secondary maxima (SdM) appeared in succession. Only very few other novae have presented so clear SdM. Both the primary maximum and all SdM occurred at later times with increasing wavelengths, by amounts in agreement with expectations from fireball expansions. The radiative energy released during SdM declined following an exponential pattern, while the breadth of individual SdM and the time interval between them widened. Emission lines remained sharp (FWHM~1000 km/s) throughout the whole nova evolution, with the exception of a broad pedestal with a trapezoidal shape ({Delta}vel=3600 km/s at the top and 4500 km/s at the bottom) which was only seen during the advanced decline from SdM maxima and was absent in between SdM. V5588 Sgr at maximum light displayed a typical FeII-class spectrum which did not evolve into a nebular stage. About 10 d into the decline from primary maximum, a typical high-ionization He/N-class spectrum appeared and remained visible simultaneously with the FeII-class spectrum, qualifying V5588 Sgr as a rare hybrid nova. While the FeII-class spectrum faded into oblivion, the He/N-class spectrum developed strong [FeX] coronal lines.
- ID:
- ivo://CDS.VizieR/J/ApJS/183/261
- Title:
- Optical photometry of the ONC
- Short Name:
- J/ApJS/183/261
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present U, B, V, I broadband, 6200{AA} TiO medium band, and H{alpha} narrow band photometry of the Orion Nebula Cluster (ONC) obtained with the WFI imager at the ESO/MPI 2.2 telescope at La Silla Observatory. The nearly simultaneous observations cover the entire ONC in a field of about 34x34arcmin^2^. They enable us to determine stellar colors avoiding the additional scatter in the photometry induced by stellar variability typical of pre-main-sequence stars. We identify 2612 point-like sources in the I band; 58%, 43%, and 17% of them are also detected in V, B, and U, respectively. 1040 sources are identified in the H{alpha} band. In this paper we present the observations, the calibration techniques adopted, and the resulting catalog. We show the derived color-magnitude diagram of the population and discuss the completeness of our photometry. We define a spectrophotometric TiO index that takes into account the fluxes in the V, I, and TiO bands. Comparing it with spectral types of ONC members in the literature, we find a correlation between the index and the spectral type valid for M-type stars, which is accurate to better than 1 spectral subclass for M3-M6 types and better than 2 spectral subclasses for M0-M2 types. This allows us to newly classify 217 stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/882/30
- Title:
- Optical photometry of type Ia SN 2014J
- Short Name:
- J/ApJ/882/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present extensive ground-based and Hubble Space Telescope (HST) photometry of the highly reddened, very nearby SN Ia 2014J in M82, covering the phases from 9 days before to about 900 days after the B-band maximum. SN 2014J is similar to other normal SNe Ia near the maximum light, but it shows flux excess in the B band in the early nebular phase. This excess flux emission can be due to light scattering by some structures of circumstellar materials located at a few 10^17^cm, consistent with a single-degenerate progenitor system or a double-degenerate progenitor system with mass outflows in the final evolution or magnetically driven winds around the binary system. At t~+300 to ~+500 days past the B-band maximum, the light curve of SN 2014J shows a faster decline relative to the 56Ni decay. That feature can be attributed to the significant weakening of the emission features around [FeIII]{lambda}4700 and [FeII]{lambda}5200 rather than the positron escape, as previously suggested. Analysis of the HST images taken at t>600 days confirms that the luminosity of SN 2014J maintains a flat evolution at the very late phase. Fitting the late-time pseudobolometric light curve with radioactive decay of ^56^Ni, ^57^Ni, and ^55^Fe isotopes, we obtain the mass ratio ^57^Ni/^56^Ni as 0.035+/-0.011, which is consistent with the corresponding value predicted from the 2D and 3D delayed-detonation models. Combined with early-time analysis, we propose that delayed-detonation through the single-degenerate scenario is most likely favored for SN 2014J.
- ID:
- ivo://CDS.VizieR/J/ApJ/806/94
- Title:
- Optical polarimetric catalog of stars in the SMC
- Short Name:
- J/ApJ/806/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new optical polarimetric catalog for the Small Magellanic Cloud (SMC). It contains a total of 7207 stars, located in the northeast (NE) and Wing sections of the SMC and part of the Magellanic Bridge. This new catalog is a significant improvement compared to previous polarimetric catalogs for the SMC. We used it to study the sky-projected interstellar magnetic field structure of the SMC. Three trends were observed for the ordered magnetic field direction at position angles (PAs) of (65{deg}+/-10{deg}), (115{deg}+/-10{deg}), and (150{deg}+/-10{deg}). Our results suggest the existence of an ordered magnetic field aligned with the Magellanic Bridge direction and SMC's Bar in the NE region, which have PAs roughly at 115.4{deg} and 45{deg}, respectively. However, the overall magnetic field structure is fairly complex. The trends at 115{deg} and 150{deg} may be correlated with the SMC's bimodal structure, observed in Cepheids' distances and HI velocities. We derived a value of B_sky_=(0.497+/-0.079){mu}G for the ordered sky-projected magnetic field, and {delta}B=(1.465+/-0.069){mu}G for the turbulent magnetic field. This estimate of B_sky_ is significantly larger (by a factor of ~10) than the line of sight field derived from Faraday rotation observations, suggesting that most of the ordered field component is on the plane of the sky. A turbulent magnetic field stronger than the ordered field agrees with observed estimates for other irregular and spiral galaxies. For the SMC the B_sky_/{delta}B ratio is closer to what is observed for our Galaxy than other irregular dwarf galaxies.
