- ID:
- ivo://CDS.VizieR/J/AJ/132/663
- Title:
- Differential Velocities of very low mass SBs
- Short Name:
- J/AJ/132/663
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the results of a survey for radial velocity variability in a heterogeneous sample of very low mass stars and brown dwarfs. One distinguishing characteristic of the survey is its time span, which allows an overlap between spectroscopic binaries and those that can be found by high angular resolution imaging. Despite our relatively low velocity precision, we are able to place a new constraint on the total binary fraction in these objects, which suggests that they are more likely the result of extending the same processes at work at higher masses into this mass range, rather than a distinct mode of formation.
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- ID:
- ivo://CDS.VizieR/II/242
- Title:
- Differential V photometry of V350 Peg
- Short Name:
- II/242
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present all the CCD photometric observations of the {delta} Scuti star V350 Peg performed by us until now. The data have been acquired between July 1997 and October 2002. A large part of it has been analysed and presented previously (Vidal, 2002A&A...394..585V). The new data of 2002 confirm the former conclusion that two frequencies of very similar amplitudes are excited in this star. The entire data set consists of 16191 measurements collected during 48 nights, and may be very helpful to investigate the detailed behaviour of this basically double-mode {delta} Scuti variable if future campaigns are held at a later stage.
- ID:
- ivo://CDS.VizieR/J/AJ/149/168
- Title:
- Differential VRI photometry of HI Dra
- Short Name:
- J/AJ/149/168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed investigation of the low-amplitude contact binary HI Dra based on the new VR_c_I_c_ CCD photometric light curves (LCs) combined with published radial velocity (RV) curves. Our completely covered LCs were analyzed using PHOEBE and revealed that HI Dra is an overcontact binary with low fill-out factor f=24+/-4(%) and temperature difference between the components of 330K. Two spotted models are proposed to explain the LC asymmetry, between which the A subtype of W UMa type eclipsing systems, with a cool spot on the less massive and cooler component, proves to be more plausible on evolutionary grounds. The results and stability of the solutions were explored by heuristic scan and parameter perturbation to provide a consistent and reliable set of parameters and their errors. Our photometric modeling and RV curve solution give the following absolute parameters of the hot and cool components, respectively: M_h_=1.72+/-0.08M_{sun}_ and M_c_=0.43+/-0.02M_{sun}_, R_h_=1.98+/-0.03R_{sun}_ and R_c_=1.08+/-0.02R_{sun}_, and L_h_=9.6+/-0.1L_{sun}_ and L_c_=2.4+/-0.1L_{sun}_. Based on these results the initial masses of the progenitors (1.11+/-0.03M_{sun}_ and 2.25+/-0.07M_{sun}_, respectively) and a rough estimate of the age of the system of 2.4Gyr are discussed.
- ID:
- ivo://CDS.VizieR/J/AJ/148/90
- Title:
- Differential VRI photometry of WW Gem
- Short Name:
- J/AJ/148/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- WW Gem is a B-type eclipsing binary with a period of 1.2378days. The CCD photometry of this binary was performed in 2013 December using the 85cm telescope at the Xinglong Stations of the National Astronomical Observatories of China. Using the updated W-D program, the photometric model was deduced from the VRI light curves. The results imply that WW Gem is a near-contact eclipsing binary whose primary component almost fills its Roche lobe. The photometric mass ratio is q_ph_=0.48(+/-0.05). All collected times of minimum light, including two new ones, were used for the period studies. The orbital period changes of WW Gem could be described by an upward parabola, possibly overlaid by a light-time orbit with a period of P_mod_=7.41(+/-0.04)yr and a semi-amplitude of A=0.0079days(+/-0.0005days), respectively. This kind of cyclic oscillation may be attributed to the light-travel time effect via the third body. The long-term period increases at a rate of dP/dt=+3.47(+/-0.04)x10^-8^day/yr, which may be explained by the conserved mass transfer from the less massive component to the more massive one. With mass transfer, the massive binary WW Gem may be evolving into a contact binary.
- ID:
- ivo://CDS.VizieR/J/A+A/423/579
- Title:
- Diffuse emissions in Carina nebula
- Short Name:
- J/A+A/423/579
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of mapping observations with ISO of [OI]63{mu}m, 145{mu}m, [NII]122{mu}m, [CII]158{mu}m, [SiII]35{mu}m, and H_2_9.66{mu}m line emissions for the Carina nebula, an active star-forming region in the Galactic plane. The observations were made for the central 40'x20' area of the nebula, including the optically bright HII region and molecular cloud lying in front of the ionized gas. Around the center of the observed area is the interface between the HII region and the molecular cloud which creates a typical photodissociation region (PDR).
- ID:
- ivo://CDS.VizieR/J/ApJ/733/91
- Title:
- Diffuse interstellar band equivalent widths
- Short Name:
- J/ApJ/733/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The diffuse interstellar bands (DIBs) are ubiquitous absorption spectral features arising from the tenuous material in the space between stars -the interstellar medium (ISM). Since their first detection nearly nine decades ago, over 400 DIBs have been observed in the visible and near-infrared wavelength range in both the Milky Way and external galaxies, both nearby and distant. However, the identity of the species responsible for these bands remains as one of the most enigmatic mysteries in astrophysics. An equally mysterious interstellar spectral signature is the 2175{AA} extinction bump, the strongest absorption feature observed in the ISM. Its carrier also remains unclear since its first detection 46 years ago. Polycyclic aromatic hydrocarbon (PAH) molecules have long been proposed as a candidate for DIBs as their electronic transitions occur in the wavelength range where DIBs are often found. In recent years, the 2175{AA} extinction bump is also often attributed to the {pi}-{pi}* transition in PAHs. If PAHs are indeed responsible for both the 2175{AA} extinction feature and DIBs, their strengths may correlate. We perform an extensive literature search for lines of sight for which both the 2175{AA} extinction feature and DIBs have been measured. Unfortunately, we found no correlation between the strength of the 2175{AA} feature and the equivalent widths of the strongest DIBs. A possible explanation might be that DIBs are produced by small free gas-phase PAH molecules and ions, while the 2175{AA} bump is mainly from large PAHs or PAH clusters in condensed phase so that there is no tight correlation between DIBs and the 2175{AA} bump.
- ID:
- ivo://CDS.VizieR/II/149
- Title:
- Diffuse Interstellar Band Measurements
- Short Name:
- II/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains diffuse band data collected from an exhaustive search of the literature and reduced to a common measurement system. The authors have adopted Herbig (1975ApJ...196..129H) as a standard data set for DIB measurements.
- ID:
- ivo://CDS.VizieR/J/ApJ/705/32
- Title:
- Diffuse interstellar bands from HD 183143
- Short Name:
- J/ApJ/705/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Echelle spectra of HD 183143 [B7Iae, E(B-V)=1.27] were obtained on three nights, at a resolving power R=38000 and with a signal-to-noise ratio ~1000 at 6400{AA} in the final, combined spectrum. A catalog is presented of 414 diffuse interstellar bands (DIBs) measured between 3900 and 8100{AA} in this spectrum. The central wavelengths, the widths (FWHM), and the equivalent widths of nearly all of the bands are tabulated, along with the minimum uncertainties in the latter. Among the 414 bands, 135 (or 33%) were not reported in four previous, modern surveys of the DIBs in the spectra of various stars, including HD 183143. The principal result of this study is that the great majority of the bands in the catalog are very weak and fairly narrow. Typical equivalent widths amount to a few m{AA}, and the bandwidths (FWHM) are most often near 0.7{AA}.
- ID:
- ivo://CDS.VizieR/J/A+A/429/559
- Title:
- Diffuse Interstellar Bands in NGC 1448
- Short Name:
- J/A+A/429/559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic VLT/UVES observations of two emerging supernovae, the Type Ia SM 2001el and the Type II SN 2003hn, in the spiral galaxy NGC 1448. Our high resolution and high signal-to-noise spectra display atomic lines of Ca II, Na I, Ti II and K I in the host galaxy. In the line of sight towards SN 2001el, we also detect over a dozen diffuse interstellar bands (DIBs) within NGC 1448.
- ID:
- ivo://CDS.VizieR/J/MNRAS/358/563
- Title:
- Diffuse Interstellar Bands in 49 stars
- Short Name:
- J/MNRAS/358/563
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We relate the equivalent widths of 11 diffuse interstellar bands, measured in the spectra of 49 stars, to different colour excesses in the ultraviolet. We find that most of the observed bands correlate positively with the extinction in the neighbourhood of the 2175{AA} bump. Correlation with colour excesses in other parts of the extinction curve is more variable from one diffuse interstellar band to another; we find that some diffuse bands (5797, 5850 and 6376{AA}) correlate positively with the overall slope of the extinction curve, while others (5780 and 6284{AA}) exhibit negative correlation. We discuss the implications of these results on the links between the diffuse interstellar band carriers and the properties of the interstellar grains.