- ID:
- ivo://CDS.VizieR/III/77
- Title:
- Copernicus 0.2-A Resolution Far-UV Stellar Spectra
- Short Name:
- III/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a subset comprising data for 60 O- and B-type stars observed by the Copernicus satellite. For each star a FITS file was created of the observed spectrum. Each spectrum has 2250 photometric data points. The wavelength range is from 1000 to 1450 Angstroems in 0.2-Angstrom steps. The data were acquired with photomultiplier U2, which had a nominal bandpass of 0.2 Angstrom (A) and scanned the spectrum with a 0.2 A step length, integrating for 13.6 sec at each wavelength position.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/160/96
- Title:
- CORALIE and PFS radial velocities of HD 86226
- Short Name:
- J/AJ/160/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Transiting Exoplanet Survey Satellite (TESS) mission was designed to find transiting planets around bright, nearby stars. Here, we present the detection and mass measurement of a small, short-period (~4days) transiting planet around the bright (V=7.9), solar-type star HD86226 (TOI-652, TIC22221375), previously known to host a long-period (~1600days) giant planet. HD86226c (TOI-652.01) has a radius of 2.16{+/-}0.08R_{Earth}_ and a mass of 7.25_-1.12_^+1.19^M_{Earth}_, based on archival and new radial velocity data. We also update the parameters of the longer-period, not-known-to-transit planet, and find it to be less eccentric and less massive than previously reported. The density of the transiting planet is 3.97g/cm^3^, which is low enough to suggest that the planet has at least a small volatile envelope, but the mass fractions of rock, iron, and water are not well- constrained. Given the host star brightness, planet period, and location of the planet near both the "radius gap" and the "hot Neptune desert," HD86226c is an interesting candidate for transmission spectroscopy to further refine its composition.
- ID:
- ivo://CDS.VizieR/J/ApJ/759/107
- Title:
- Core-collapse SNe and host galaxies
- Short Name:
- J/ApJ/759/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used images and spectra of the Sloan Digital Sky Survey to examine the host galaxies of 519 nearby supernovae (SN). The colors at the sites of the explosions, as well as chemical abundances, and specific star formation rates (SFRs) of the host galaxies provide circumstantial evidence on the origin of each SN type. We examine separately SN II, SN IIn, SN IIb, SN Ib, SN Ic, and SN Ic with broad lines (SN Ic-BL). For host galaxies that have multiple spectroscopic fibers, we select the fiber with host radial offset most similar to that of the SN. Type Ic SN explode at small host offsets, and their hosts have exceptionally strongly star-forming, metal-rich, and dusty stellar populations near their centers. The SN Ic-BL and SN IIb explode in exceptionally blue locations, and, in our sample, we find that the host spectra for SN Ic-BL show lower average oxygen abundances than those for SN Ic. SN IIb host fiber spectra are also more metal-poor than those for SN Ib, although a significant difference exists for only one of two strong-line diagnostics. SN Ic-BL host galaxy emission lines show strong central specific SFRs. In contrast, we find no strong evidence for different environments for SN IIn compared to the sites of SN II. Because our SN sample is constructed from a variety of sources, there is always a risk that sampling methods can produce misleading results. We have separated the SN discovered by targeted surveys from those discovered by galaxy-impartial searches to examine these questions and show that our results do not depend sensitively on the discovery technique.
- ID:
- ivo://CDS.VizieR/J/A+A/620/A163
- Title:
- Cores in California molecular cloud
- Short Name:
- J/A+A/620/A163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We extracted 300 cores, of which 33 are protostellar and 267 are starless cores. About 51% (137 of 267) of the starless cores are prestellar cores. Three cores have the potential to evolve into high-mass stars. The prestellar core mass function (CMF) can be well fit by a log-normal form. The high-mass end of the prestellar CMF shows a power-law form with an index {alpha}=-0.9+/-0.1 that is shallower than that of the Galactic field stellar mass function. Combining the mass transformation efficiency ({epsilon}) from the prestellar core to the star of 15+/-1% and the core formation efficiency (CFE) of 5.5%, we suggest an overall star formation efficiency of about 1% in the CMC. In the single-pointing observations with the IRAM 30m telescope, we find that 6 cores show blue-skewed profile, while 4 cores show red-skewed profile. [HCO^+^]/[HNC] and [HCO^+^]/[N_2_H^+^] in protostellar cores are higher than those in prestellar cores; this can be used as chemical clocks. The best-fit chemical age of the cores with line observations is ~50000 years.
- ID:
- ivo://CDS.VizieR/J/MNRAS/415/1577
- Title:
- CoRoT 105288363 Blazhko modulation
- Short Name:
- J/MNRAS/415/1577
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the COnvection, ROtation and planetary Transits (CoRoT) star 105288363, a new Blazhko RR Lyrae star of type RRab (f0=1.7623d^-1^), observed with the CoRoT spacecraft during the second long run in the direction of the Galactic Centre (LRc02, time-base 145d). The CoRoT data are characterized by an excellent time-sampling and a low noise amplitude of 0.07mmag in the 2-12d^-1^ range and allow us to study not only the fine details of the variability of the star, but also long-term changes in the pulsation behaviour and the stability of the Blazhko cycle. We use, among other methods, standard Fourier analysis techniques and O-C diagrams to investigate the pulsational behaviour of the Blazhko star 105288363. In addition to the frequency pattern expected for a Blazhko RR Lyrae star, we find an independent mode (f1=2.984d^-1^) showing a f0/f1 ratio of 0.59 which is similar to that observed in other Blazhko RR Lyrae stars. The bump and hump phenomena are also analysed, with their variations over the Blazhko cycle. We carefully investigated the strong cycle-to-cycle changes in the Blazhko modulation (P_B_=35.6d), which seem to happen independently and partly diametrically in the amplitude and phase modulations. Furthermore, the phasing between the two types of modulations is found to change during the course of the observations.
- ID:
- ivo://CDS.VizieR/J/A+A/565/A55
- Title:
- CoRoT 105906206 frequencies analysis
- Short Name:
- J/A+A/565/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Eclipsing binary systems with pulsating components allow determination of several physical parameters of the stars, such as mass and radius, that can be used to constrain the modeling of stellar interiors and evolution when combined with the pulsation properties. We present the results of the study of CoRoT 105906206, an eclipsing binary system with a pulsating component located in the CoRoT LRc02 field. The analysis of the CoRoT light curve was complemented by high-resolution spectra from the Sandiford at McDonald Observatory and FEROS at ESO spectrographs, which revealed a double-lined spectroscopic binary. We used an iterative procedure to separate the pulsation-induced photometric variations from the eclipse signals. First, a Fourier analysis was used to identify the significant frequencies and amplitudes due to pulsations. Second, after removing the contribution of the pulsations from the light curve we applied the PIKAIA genetic-algorithm approach to derive the best parameters for describing the system orbital properties.
- ID:
- ivo://CDS.VizieR/J/A+A/556/A87
- Title:
- CoRoT-100866999 frequency analysis
- Short Name:
- J/A+A/556/A87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The presence of g- and p-modes allows testing stellar models from the core to the envelope. Moreover, binarity in an eclipsing system constrains the physical parameters of the pulsating star. CoRot ID 100866999 is a relatively large-amplitude hybrid gamma Doradus-delta Scuti star with two clearly distinct frequency domains. The large number of detected frequencies allows a detailed study of the interaction between them. In addition, we can derive the fundamental parameters of both components from the study of the eclipsing light curve. After removing the eclipsing phases, we analyzed the data with the Period04 package up to a signal-to-noise ratio S/N=4. The light curve was then prewhitened with these oscillation frequencies to derive the fundamental parameters of the two components.
- ID:
- ivo://CDS.VizieR/J/A+A/552/A60
- Title:
- CoRoT 102918586 light curve and spectra
- Short Name:
- J/A+A/552/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Pulsating stars in eclipsing binary systems are powerful tools to test stellar models. Binarity enables us to constrain the pulsating component physical parameters and this knowledge drastically improves the input physics for asteroseismic studies. The study of stellar oscillations then allows us to improve our understanding of stellar interiors and stellar evolution. The space mission CoRoT discovered several promising objects suitable for these studies. They were photometrically observed with unprecedented accuracy, but needed spectroscopic follow-up. A promising target was the relatively bright eclipsing system CoRoT 102918586, which turned out to be a double-lined spectroscopic binary and also showed clear evidence of Gamma Dor type pulsations. With the aim of combining the information from binarity and pulsation and fully exploiting the potential of CoRoT photometry we obtained phase resolved high-resolution spectroscopy with the Sandiford spectrograph at the McDonald 2.1m telescope and the FEROS spectrograph at the ESO 2.2m telescope. Spectroscopy yielded both the radial velocity curves and, after spectra disentangling, the component effective temperatures, metallicity, and line-of-sight projected rotational velocities. The CoRoT light curve was analyzed with an iterative procedure, devised to disentangle eclipses from pulsations. The eclipsing binary light curve analysis, combined with the spectroscopic results, provided an accurate determination of the system parameters, and the comparison with evolutionary models provided strict constraints on the system age. Finally, the residuals obtained after subtraction of the best fitting eclipsing binary model were analyzed to determine the pulsator properties. We achieved a complete and consistent description of the system. The primary star pulsates with typical gamma Dor frequencies and shows a splitting in period that is consistent with high order g-mode pulsations in a star of the corresponding physical parameters. The value of the splitting, in particular, is consistent with pulsations in l=1 modes.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A146
- Title:
- CoRoT 0105288363 light curves
- Short Name:
- J/A+A/527/A146
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CoRoT - Convection Rotation and Planetary Transits - space mission provides a unique opportunity to monitor RR Lyrae stars with excellent time-sampling, unprecedented photometric precision, and a long time base of 150 days. The pulsation characteristics of RR Lyrae stars rely on robust physics, but we still lack a firm quantitative understanding of the physical mechanisms driving the Blazhko modulation and the long-term changes in their pulsation behavior. We use the high- precision space data of an unknown RR Lyrae star CoRoT ID 0105288363 observed during a second long run centered on the Galaxy -LRc02-, to improve our understanding of the pulsation properties of RR Lyrae stars.
- ID:
- ivo://CDS.VizieR/J/A+A/510/A39
- Title:
- CoRoT light curves of V1127 Aql
- Short Name:
- J/A+A/510/A39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CoRoT space mission - Convection Rotation and Planetary Transits - is a great opportunity for monitoring stars with excellent time-sampling and unprecedented photometric precision for up to 150days. As an important benefit, high-quality RR Lyrae light curves are obtained with a quasi-uninterrupted coverage over several pulsation and Blazhko cycles. The Blazhko effect in RR Lyrae stars is an unsolved problem of astrophysics. We used the high-precision space data to contribute with more precise knowledge to clear up the possible physical processes behind the phenomenon. We applied different period finding techniques including Period04, MuFrAn, PDM and SigSpec. Amplitude and phase modulation were investigated by an analytical function method as well as with the traditional O-C diagrams. The Blazhko modulation frequency is directly detected in the spectrum, as well as its first and second harmonics. It shows the non-linear nature of the Blazhko modulation. Besides the triplets, further higher-order modulation side peaks appear around the pulsation frequency as quintuplet, septuplet, nonuplet, undecaplet, tredecaplet, quindecaplet and septdecaplet structures. Additional frequencies, not belonging to the classical multiplet structures, are detected, and their linear combinations with the fundamental radial mode. We interpret these additional terms as non-radial modes. During the five consecutive Blazhko cycles, there is a shift of the maximum phase around 0.011 pulsation phase which is likely the consequence of a long term modulation.
