- 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.
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- ID:
- ivo://CDS.VizieR/J/AJ/158/193
- Title:
- Photometric data of V582 Lyr and V1016 Oph
- Short Name:
- J/AJ/158/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new CCD photometric light curves about two eclipsing binaries of V582 Lyr and V1016 Oph. Our observations were carried out by the SARA 91.4 cm telescope of America in 2016 and the 60 cm telescope of Chile in 2018. V582 Lyr's spectra type was classified as K5, and its radial velocity was determined using the LAMOST spectral survey. There are absorptions in the observed H{alpha} line and excess emissions in the subtracted H{alpha} line, which show weak chromospheric activity. We obtained the updated ephemeris information for V582 Lr and V1016 Oph, and found that their orbital periods are both decreasing. We concluded that the decreased rate is -0.474 (+/-0.011)x10^-7^ days/yr for V582 Lyr and 3.460 (+/-0.014)x10^-7^ days/yr for V1016 Oph. For V582 Lyr, the period variation was interpreted as a mass transfer from the secondary component to the primary one, and the corresponding rate is dM_2_/dt=-1.10 (+/-0.03)x10^-7^ M_{sun}_/yr. For V1016 Oph, we explain it by transferring from the primary component to the secondary one, and the corresponding rate is dM_1_/dt=-2.69 (+/-0.04)x10^-7^ M_{sun}_/yr. The photometric solution of V1016 Oph was obtained by analyzing the CCD photometry with the Wilson-Devinney program. We also obtained the orbital parameters of V1016 Oph by simultaneously analyzing our BVRI light curves and radial-velocity curve from the LAMOST low-resolution spectral survey. Finally, our orbital solution shows that they are contact eclipsing binaries with contact factors of 3.35 (+/-0.08)% for V582 Lyr and 41.0 (+/-0.1)% for V1016 Oph.
- ID:
- ivo://CDS.VizieR/J/MNRAS/444/711
- Title:
- Photometric distances of exoplanets
- Short Name:
- J/MNRAS/444/711
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Colour-magnitude diagrams form a traditional way of presenting luminous objects in the Universe and compare them to each other. Here, we estimate the photometric distance of 44 transiting exoplanetary systems. Parallaxes for seven systems confirm our methodology. Combining those measurements with fluxes obtained while planets were occulted by their host stars, we compose colour-magnitude diagrams in the near and mid-infrared. When possible, planets are plotted alongside very low mass stars and field brown dwarfs, who often share similar sizes and equilibrium temperatures. They offer a natural, empirical, comparison sample. We also include directly imaged exoplanets and the expected loci of pure blackbodies. Irradiated planets do not match blackbodies; their emission spectra are not featureless. For a given luminosity, hot Jupiters' daysides show a larger variety in colour than brown dwarfs do and display an increasing diversity in colour with decreasing intrinsic luminosity. The presence of an extra absorbent within the 4.5{mu}m band would reconcile outlying hot Jupiters with ultra-cool dwarfs' atmospheres. Measuring the emission of gas giants cooler than 1000K would disentangle whether planets' atmospheres behave more similarly to brown dwarfs' atmospheres than to blackbodies, whether they are akin to the young directly imaged planets, or if irradiated gas giants form their own sequence.
- ID:
- ivo://CDS.VizieR/J/ApJ/694/1559
- Title:
- Photometric follow-up observations of GJ 436b
- Short Name:
- J/ApJ/694/1559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents multiband photometric follow-up observations of the Neptune-mass transiting planet GJ 436b, consisting of five new ground-based transit light curves obtained in 2007 May. Together with one already published light curve, we have at hand a total of six light curves, spanning 29 days. The analysis of the data yields an orbital period P=2.64386+/-0.00003 days, midtransit time T_c_[HJD]=2454235.8355+/-0.0001, planet mass M_p_=23.1+/-0.9M_{earth}_=0.073+/-0.003M_Jup_, planet radius R_p_=4.2+/-0.2R_{earth}_=0.37+/-0.01R_Jup_, and stellar radius R_s_=0.45+/-0.02R_{sun}_. Our typical precision for the midtransit timing for each transit is about 30s. We searched the data for a possible signature of a second planet in the system through transit timing variations (TTV) and variation of the impact parameter. The analysis could not rule out a small, of the order of a minute, TTV and a long-term modulation of the impact parameter, of the order of +0.2yr^-1^.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJS/191/389
- Title:
- Photometric monitoring in {sigma} Ori cluster
- Short Name:
- J/ApJS/191/389
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-precision photometry on 107 variable low-mass stars and brown dwarfs in the ~3Myr {sigma} Orionis open cluster. We have carried out I-band photometric monitoring within two fields, encompassing 153 confirmed or candidate members of the low-mass cluster population, from 0.02 to 0.5M_{sun}_. We are sensitive to brightness changes on timescales from 10 minutes to two weeks with amplitudes as low as 0.004mag, and find variability on these timescales in nearly 70% of cluster members. We identify both periodic and aperiodic modes of variability, as well as semi-periodic rapid fading events that are not accounted for by the standard explanations of rotational modulation of surface features or accretion. We have incorporated both optical and infrared color data to uncover trends in variability with mass and circumstellar disks.
- 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.
- ID:
- ivo://CDS.VizieR/J/AJ/158/180
- Title:
- Photometric observations of AE Cassiopeia
- Short Name:
- J/AJ/158/180
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- AE Cas was observed some 40 yr ago by Srivastava & Kandpal (1984AcA....34..281S) and was analyzed by Kopal's Fourier frequency-domain technique. No further precision observations have taken place until the present study, which represents the first modern synthetic analysis of light curves using the 2016 version of the Wilson-Devinney (W-D) Program. It was observed in 2015 October 2, 3 and 23, inclusive, at Dark Sky Observatory in North Carolina with the 0.81 m reflector of Appalachian State University and the 0.9 m reflector at Kitt Peak National Observatory remotely through the Southeastern Association for Research in Astronomy (SARA) consortia. V, R_c_, I_c_ observations were taken. Five times of minimum light were determined from our present observations, which include three primary eclipses and two secondary eclipses. In addition, eight observations at minima were introduced as low weighted times of minimum light from archived All-Sky Automated Survey for Supernovae Variable Star Catalog (ASAS) data and 74 times of minimum light from the literature, some of which were from visual observations. This period study covers an interval of some 89 yr. The period was found to be decaying at a constant rate with a high level of confidence. A VR_c_I_c_ simultaneous W-D Program solution indicates that the system has a mass ratio somewhat less than unity (q=0.856+/-0.001), and a component temperature difference of ~2060 K. A q-search was performed and the mass ratio minimized at the above value. The large temperature difference in the components verifies that the binary is not yet in contact. No spots were needed for the solution. The fill-out of our model is 83.2% for the primary component (smaller radius) and 99.1% for the secondary component. So, it is near a classical Algol configuration.
- ID:
- ivo://CDS.VizieR/J/A+AS/113/473
- Title:
- Photometric observations of PMS objects
- Short Name:
- J/A+AS/113/473
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the observational data of a photometric monitoring of 24 pre-main sequence objects: T Tauri stars, Ae/Be Herbig stars and some unclassified objects. Observations were carried out from July 1988 to August 1992, using the UBV(RI)_c system. Variability with time scales from days to years and amplitudes in the V band larger than 0.1 mag is found for a part of this sample. The analysis of the possible causes of this variability are discussed in separate papers (Fernandez & Eiroa 1995a,b).
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/1876
- Title:
- Photometric observations of SN PTF11iqb
- Short Name:
- J/MNRAS/449/1876
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The supernova (SN) PTF11iqb was initially classified as a Type IIn event caught very early after explosion. It showed narrow Wolf-Rayet (WR) spectral features on day 2 (as in SN 1998S and SN 2013cu), but the narrow emission weakened quickly and the spectrum morphed to resemble Types II-L and II-P. At late times, H{alpha} exhibited a complex, multipeaked profile reminiscent of SN 1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN 1998S, although with somewhat weaker interaction with circumstellar material (CSM) at early times, and stronger interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for CSM interaction (with a mass-loss rate of roughly 10^-4^ M_{sun}_/yr) added to the light curve of a normal SN II-P. The underlying plateau requires a progenitor with an extended hydrogen envelope like a red supergiant at the moment of explosion, consistent with the slow wind speed (<80 km/s) inferred from narrow H{alpha} emission. The cool supergiant progenitor is significant because PTF11iqb showed WR features in its early spectrum - meaning that the presence of such WR features does not necessarily indicate a WR-like progenitor. Overall, PTF11iqb bridges SNe IIn with weaker pre-SN mass-loss seen in SNe II-L and II-P, implying a continuum between these types.
