- ID:
- ivo://CDS.VizieR/J/ApJ/877/75
- Title:
- BVRI photom. of DV Psc and known short-period EBs
- Short Name:
- J/ApJ/877/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using 27 sets of new multiband photometry light curves acquired from our long-term photometric campaign carried out in the last 5yr and high-resolution spectroscopic data from seven nights, we analyzed the physical mechanisms of period variation, starspot cycle, optical flares, and chromospheric activities of the eclipsing binary DV Psc. Our updated O-C diagram covering a period of approximately 20yr shows an oscillation in its orbital period. This variations might be caused by a third body with an orbital period of 14.58+/-0.28yr. There are two active regions of starspots at longitude belts of about 90{deg} and 270{deg}. We obtained its starspot cycles with periods of 3.60+/-0.03yr and 3.42+/-0.02yr at about 90{deg} and 270{deg}, respectively. Moreover, the magnitude difference of Max.I-Max.II shows cyclic oscillation of 5.15+/-0.01yr. During our decade long photometric campaign, we observed DV Psc a total of 326.4hr, detected 18 outbursts (12 of them have never been reported) with flare energies in the range of (6.62-1106.85)x10^24^J. The slope of the relationship between the phase of the max flare and spots is 0.842 +/-0.083, implying a correlation between spots and flares. We discovered evidence for a correlation between the rotation period and the activity cycle for the short-period eclipsing binaries. Our high-resolution spectroscopic observations of DV Psc show obvious emissions above continuum in the H{alpha} line and small self-reversal emissions of the CaII IRT lines.
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- ID:
- ivo://CDS.VizieR/J/ApJ/650/1160
- Title:
- BVRIr photometry of HD 189733
- Short Name:
- J/ApJ/650/1160
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the BVRI multiband follow-up photometry of the transiting extrasolar planet HD 189733b. We revise the transit parameters and find a planetary radius of Rp=1.154+/-0.033R_J_ and an inclination of i_P_=89.79+/-0.24{deg}. The new density (~1g/cm^3^) is significantly higher than the former estimate (~0.75g/cm^3^); this shows that from the current sample of nine transiting planets, only HD 209458 (and possibly OGLE-10b) have anomalously large radii and low densities. We note that due to the proximity of its parent star, HD 189733b currently has one of the most precise radius determinations among extrasolar planets. We calculate new ephemerides, P=2.218573+/-0.000020-days and T0=2453639.39420+/-0.00024 (HJD), and estimate the timing offsets of the 11 distinct transits with respect to the predictions of a constant orbital period, which can be used to reveal the presence of additional planets in the system.
- ID:
- ivo://CDS.VizieR/J/ApJ/875/136
- Title:
- BVRI, spectra & IR obs. of type II-P SN2017eaw
- Short Name:
- J/ApJ/875/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present extensive optical photometric and spectroscopic observations, from 4 to 482 days after explosion, of the Type II-plateau (II-P) supernova (SN) 2017eaw in NGC 6946. SN 2017eaw is a normal SN II-P intermediate in properties between, for example, SN 1999em and SN 2012aw and the more luminous SN 2004et, also in NGC6946. We have determined that the extinction to SN 2017eaw is primarily due to the Galactic foreground and that the SN site metallicity is likely subsolar. We have also independently confirmed a tip-of-the-red-giant-branch (TRGB) distance to NGC 6946 of 7.73+/-0.78Mpc. The distances to the SN that we have also estimated via both the standardized candle method and expanding photosphere method corroborate the TRGB distance. We confirm the SN progenitor identity in pre-explosion archival Hubble Space Telescope (HST) and Spitzer Space Telescope images, via imaging of the SN through our HST Target of Opportunity program. Detailed modeling of the progenitor's spectral energy distribution indicates that the star was a dusty, luminous red supergiant consistent with an initial mass of ~15M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/PASJ/55/1079
- Title:
- BVRi'z'JHKs photometry of ERO objects
- Short Name:
- J/PASJ/55/1079
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied the evolution of elliptical galaxies at z>~1 using a sample of 247 Extremely Red Objects (EROs) with R-Ks>3.35 (AB) and Ks<=22.1 (AB) constructed from BVRi'z'JHKs multicolor data of a 114arcmin^2^ area in the Subaru/XMM-Newton Deep Field taken with the Subaru Telescope and the UH 2.2m telescope. By fitting template spectra of old galaxies (OGs) and young, dusty starbursts (DSs) to the multicolor data, we classified EROs into these two classes and estimated their redshifts. We found that 58% of the EROs in our sample belong to the OG class and that these OGs have a wide range of colors at any redshift. We derived rest-frame B-band luminosity functions of OGs in our sample at z=1-1.5 and 1.5-2.5, and found that the number density of galaxies obeying passive evolution drops at z>~1.5 by a factor of three or more. The spatial correlation length of OGs is estimated to be r_0_>~8h^-1^Mpc, which is comparable to, or larger than, those of present-day early-type galaxies of similar luminosities. We also discussed properties of DSs in our data.
- ID:
- ivo://CDS.VizieR/J/ApJS/162/80
- Title:
- BVRJHKgr photometry of bright spiral galaxies
- Short Name:
- J/ApJS/162/80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometrically calibrated images and surface photometry in the B, V, R, J, H, and K bands of 25, and in the g, r, and K bands of five nearby bright (B^0^_T_<12.5 mag) spiral galaxies with inclinations of 30{deg}-65{deg} spanning the Hubble sequence from Sa to Scd. Data are from The Ohio State University Bright Spiral Galaxy Survey (Eskridge et al., Cat. <J/ApJS/143/73>), the Two Micron All Sky Survey (2006AJ....131.1163S), and the Sloan Digital Sky Survey Second Data Release (Abazajian et al., 2004AJ....128..502A). Radial surface brightness profiles are extracted, and integrated magnitudes are measured from the profiles. Axis ratios, position angles, and scale lengths are measured from the near-infrared images. A one-dimensional bulge/disk decomposition is performed on the near-infrared images of galaxies with a nonnegligible bulge component, and an exponential disk is fit to the radial surface brightness profiles of the remaining galaxies.
- ID:
- ivo://CDS.VizieR/J/PASP/121/1366
- Title:
- BVR light curves of BX Peg
- Short Name:
- J/PASP/121/1366
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of new CCD photometry for the contact binary BX Peg, made during three successive months beginning on 2008 September. As do historical light curves, our observations display an O'Connell effect and the November data by themselves indicate clear evidence for very short-term brightness disturbance.
- ID:
- ivo://CDS.VizieR/J/AJ/146/35
- Title:
- BVR light curves of DZ Psc
- Short Name:
- J/AJ/146/35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New multi-color photometry for the eclipsing binary DZ Psc was performed in 2011 and 2012 using the 85cm telescope at the Xinglong Station of the National Astronomical Observatories of China. Using the updated Wilson-Devinney (W-D) code, we deduced two sets of photometric solutions. The overcontact degree is f=89.7(+/-1.0)%, identifying DZ Psc as a deep, low mass ratio overcontact binary. The asymmetric light curves (i.e., LC_2_ in 2012) were modeled by a hot spot on the primary star. Based on all of the available light minimum times, we discovered that the orbital period of DZ Psc may be undergoing a secular period increase with a cyclic variation. The modulated period and semi-amplitude of this oscillation are P_mod_=11.89(+/-0.19)yr and A=0.0064(+/-0.0006)days, which may be possibly attributed to either cyclic magnetic activity or light-time effect due to the third body. The long-term period increases at a rate of dP/dt=+7.13(+/-0.17)*10^-7^days/yr, which may be interpreted as conserved mass transfer from the less massive component to the more massive one. With mass transferring, DZ Psc will finally merge into a rapid-rotation single star when J_spin_/J_orb_>1/3.
- ID:
- ivo://CDS.VizieR/J/A+A/537/A109
- Title:
- BVR light curves of GK Boo and AE For
- Short Name:
- J/A+A/537/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of late-type low-mass eclipsing binaries provides us with important information about the most common stars in the Universe. We obtain the first light curves and perform period analyses of two neglected eclipsing binaries GK Boo and AE For to reveal their basic physical properties. We performed both a period analysis of the times of the minima and a BVR light curve analysis. Many new times of minima for both the systems were derived and collected from the data obtained by automatic and robotic telescopes. This allowed us to study the long-term period changes in these systems for the first time. From the light curve analysis, we derived the first rough estimates of the physical properties of these systems.
- ID:
- ivo://CDS.VizieR/J/A+A/519/A78
- Title:
- BVR light curves of KR Com
- Short Name:
- J/A+A/519/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the detailed analysis of triple system KR Com with different observational techniques - photometry, interferometry, and period variation. The use of BVR photometry of the close-contact binary KR Com, which is the primary component of a triple system, helps us to better describe the properties of the components. The interferometric data obtained during the last 30 years sufficiently determine the visual orbit, but the use of minima timings of KR Com for the study of period variation together with the visual orbit is a novel approach in this system.
- ID:
- ivo://CDS.VizieR/J/AJ/140/319
- Title:
- BVR light curves of NGC 6026 and 6337
- Short Name:
- J/AJ/140/319
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Close-binary central stars of planetary nebulae (CSPNe) provide an opportunity to explore the evolution of PNe, their shaping, and the evolution of binary systems undergoing a common-envelope phase. Here, we present the results of time-resolved photometry of the binary central stars (CSs) of the PNe NGC 6026 and NGC 6337 as well as time-resolved spectroscopy of the CS of NGC 6026. The results of a period analysis give an orbital period of 0.528086(4) days for NGC 6026 and a photometric period of 0.1734742(5) days for NGC 6337.
