A5036307198- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Superconducting Materials and Applications
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- Particle accelerators and beam dynamics
- Astrophysics and Star Formation Studies
- Geological and Geophysical Studies
- Neutrino Physics Research
- Particle Accelerators and Free-Electron Lasers
- Adaptive optics and wavefront sensing
- Cardiac Imaging and Diagnostics
- Dark Matter and Cosmic Phenomena
- Advanced X-ray and CT Imaging
- Space Science and Extraterrestrial Life
- Nuclear Physics and Applications
- Calibration and Measurement Techniques
- Medical Imaging Techniques and Applications
- Historical Astronomy and Related Studies
Instituto de Astrofísica de Canarias
2022-2024
Universidad de La Laguna
2022-2024
The Ohio State University
2016-2023
We present ground-based and Swift photometric spectroscopic observations of the tidal disruption event (TDE) ASASSN-15oi, discovered at centre 2MASX J20390918−3045201 (d ≃ 216 Mpc) by All-Sky Automated Survey for SuperNovae. The source peaked a bolometric luminosity L 1.3 × 1044 erg s−1 radiated total energy E 6.6 1050 over first ∼3.5 months observations. early optical/UV emission can be fit blackbody with temperature increasing from T ∼ 2 104 K to 4 while declines 2.3 1043 s−1, requiring...
Abstract In the third APOKASC catalog, we present data for complete sample of 15,808 evolved stars with APOGEE spectroscopic parameters and Kepler asteroseismology. We used 10 independent asteroseismic analysis techniques anchor our system on fundamental radii derived from Gaia L T eff . provide evolutionary state, surface gravity, mass, radius, age, to derive them 12,418 stars. This includes 10,036 exceptionally precise measurements, median fractional uncertainties in <mml:math...
This catalog summarizes information for all supernovae discovered by the All-Sky Automated Survey SuperNovae (ASAS-SN) and other bright ($m_{peak}\leq17$), spectroscopically confirmed in 2016. We then gather near-IR through UV magnitudes of host galaxies offsets from centers their hosts public databases. illustrate results using a sample that now totals 668 since 2014 May 1, including our previous catalogs, with type distributions closely matching those ideal magnitude limited Li et al....
The period versus mass diagrams (i.e., rotational sequences) of open clusters provide crucial constraints for angular momentum evolution studies. However, their memberships are often heavily contaminated by field stars, which could potentially bias the interpretations. In this paper, we use data from Gaia DR2 to re-assess seven with ground- and space-based data, present an updated view stellar rotation as a function age. We astrometry identify cluster members in phase-space, photometry...
The rotation rates of main-sequence stars slow over time as they gradually lose angular momentum to their magnetized stellar winds. rate loss depends on the strength and morphology magnetic field, mass-loss rate, period, mass, radius. Previous observations suggested a shift in between two F-type with similar but very different ages (88 Leo rho CrB). In this Letter, we identify comparable transition an evolutionary sequence solar analogs 2-7 Gyr. We present new spectropolarimetry 18 Sco 16...
Stellar rotation is a complex function of mass, metallicity, and age can be altered by binarity. To understand the importance these parameters in main sequence stars, we have assembled sample observations that spans range using combination from The Transiting Exoplanet Survey Satellite (TESS) Kepler Space Telescope. We find while measure periods identify other classes stellar variability (e.g., pulsations) TESS lightcurves, instrument systematics prevent detection signals longer than orbital...
This manuscript presents information for all supernovae discovered by the All-Sky Automated Survey SuperNovae (ASAS-SN) during 2015, its second full year of operations. The same is presented bright (mV ≤ 17), spectroscopically confirmed other sources in 2015. As with first ASAS-SN supernova catalogue, we also present redshifts and near-ultraviolet through infrared magnitudes host galaxies both samples. Combined our previous this work comprises a complete catalogue 455 from multiple...
Given its peak luminosity and early-time spectra, ASASSN-15lh was classified as the most luminous supernova (SN) ever discovered (Dong et al. 2016). Here we report a UV rebrightening of observed with Swift during our follow-up campaign. The began at $t \simeq$ 90 days (observer frame) after primary followed by $\sim 120$-day long plateau in bolometric luminosity, before starting to fade again $t\simeq 210$ days. rebrightened bands $\Delta m_{UVW2} \simeq -1.75$ mag, m_{UVM2} -1.25$ m_{UVW1}...
Abstract The ages of solar-like stars have been at the center many studies such as exoplanet characterization or Galactic-archeology. While are usually computed from stellar evolution models, relations linking to other properties, rotation and magnetic activity, investigated. With large catalog 55,232 periods, P rot , photometric activity index, S ph Kepler data, we opportunity look for magneto-gyro-chronology relations. Stellar obtained with two codes that include treatment angular momentum...
Context. Typical uncertainties of ages determined for single star giants from isochrone fitting using single-epoch spectroscopy and photometry without any additional constraints are 30-50 %. Binary systems, particularly double-lined spectroscopic (SB2) binaries, provide an opportunity to study the intricacies internal stellar physics better determine parameters, age. Aims. By binarity asteroseismology, we aim obtain precise age parameters red giant-subgiant binary system KIC 9163796, a with...
The original Kepler mission has delivered unprecedented high-quality photometry. These data have impacted numerous research fields (e.g., asteroseismology and exoplanets), continue to be an astrophysical goldmine. Because of this, thorough investigations the ~ 200,000 stars observed by remain paramount importance. In this paper, we present a state-of-the-art characterization targets based on Gaia DR3 data. We place color-magnitude diagram (CMD), account for effects interstellar extinction,...
There is now a large sample of stars observed by the Kepler satellite with measured rotation periods and photometric activity index $S_{\rm ph}$. We use this data, in conjunction stellar interiors models, to explore interplay magnetism, rotation, convection. Stellar proxies other than ph}$ are correlated Rossby number, $Ro$, or ratio period convective overturn timescale. compute latter using Yale Rotating Evolution Code models. observe different ph}$-$Ro$ relationships for spectral types....
The typical uncertainties of ages determined for single star giants from isochrone fitting using single-epoch spectroscopy and photometry without any additional constraints are 30-50,%. Binary systems, particularly double-lined spectroscopic binaries, provide an opportunity to study the intricacies internal stellar physics better determine parameters, age. By binarity asteroseismology, we aim obtain precise age parameters red giant-subgiant binary system a with mass ratio 1.015 but...
The original kepler mission has delivered unprecedented high-quality photometry. These data have impacted numerous research fields (e.g., asteroseismology and exoplanets), continue to be an astrophysical goldmine. Because of this, thorough investigations the ∼ 200,000 stars observed by remain paramount importance. In this paper, we present a state-of-the-art characterization targets based on gaia DR3 data. We placed color-magnitude diagram (CMD), accounted for effects interstellar...
Abstract There is now a large sample of stars observed by the Kepler satellite with measured rotation periods and photometric activity index S ph . We use this data, in conjunction stellar interiors models, to explore interplay magnetism, rotation, convection. Stellar proxies other than are correlated Rossby number, Ro, or ratio period convective overturn timescale. compute latter using Yale Rotating Evolution Code models. observe different –Ro relationships for spectral types. Though...
Stellar rotation and magnetic activity have a complex evolution that reveals multiple regimes. One of the related transitions is seen in distribution for main-sequence (MS) solar-like stars has been attributed to core-envelope coupling consequent angular-momentum transfer between fast core slow envelope. This feature known as spin-down stalling intermediate-rotation gap field stars. Beyond this signature, we search evidence it stellar activity. We investigated 1 Gyr old NGC 6811, cluster, MS...
The photometric time series of solar-like stars can exhibit rotational modulation due to active regions co-rotating with the stellar surface, allowing us constrain rotation and magnetic activity. In this work we investigate behavior, particularly variability, activity Kepler compare it that Sun. We adopted proxy Sph, which was computed a cadence 5 x period, Prot. average Sph taken as mean level, standard deviation measure temporal variation over observations. also analyzed Sun-as-a-star data...
Abstract The bright star λ Ser hosts a hot Neptune with minimum mass of 13.6 M ⊕ and 15.5 day orbit. It also appears to be solar analog, mean rotation period 25.8 days surface differential very similar the Sun. We aim characterize fundamental properties this system constrain evolutionary pathway that led its present configuration. detect solar-like oscillations in time series photometry from Transiting Exoplanet Survey Satellite, we derive precise asteroseismic detailed modeling. obtain new...
TOI-1416 (BD+42 2504, HIP 70705) is a V =10 late G- or early K-type dwarf star. TESS detected transits in its Sectors 16, 23, and 50 with depth of about 455 ppm period 1.07 days. Radial velocities (RVs) confirm the presence transiting planet b , which has mass 3.48 ± 0.47 M ⊕ radius 1.62 0.08 R implying slightly sub-Earth density 4.50 −0.83 +0.99 g cm −3 . The RV data also further indicate tentative planet, c 27.4 29.5 days, whose nature cannot be verified due to strong suspicions...
While the mission’s primary goal was focused on exoplanet detection and characterization, Kepler made continues to make extraordinary advances in stellar physics. Stellar rotation magnetic activity are no exceptions. allowed for these properties be determined tens of thousands stars from main sequence up red giant branch. From photometry, this can achieved by investigating brightness fluctuations due active regions, which cause surface inhomogeneities, or through asteroseismology as...
In 2013 a dearth of close-in planets around fast-rotating host stars was found using statistical tests on Kepler data. The addition more and Transiting Exoplanet Survey Satellite (TESS) systems in 2022 filled this region the diagram stellar rotation period ( P rot ) versus planet orbital orb ). We revisited extraction planet-host stars, we classify by their spectral type, studied – relations. only used confirmed exoplanet to minimize biases. order learn about physical processes at work,...
Previous studies have found that red giants (RGs) in close binary systems undergoing spin-orbit resonance exhibit an enhanced level of magnetic activity with respect to single RGs rotating at the same rate, from measurements photometric variability $S'_{ph}$ and chromospheric emission S-index $S_{Ca_{II}}$. Here, we consider a sample 4465 observed by NASA Kepler mission measure additional indicators probe different heights chromosphere: near-ultraviolet (NUV) excess GALEX data, indices based...
The NASA K2 mission that succeeded the nominal Kepler observed several hundreds of thousands stars during its operations. While most were in single campaigns 80 days, some them targeted for more than one campaign. We perform an asteroseismic study a sample eight solar-like Campaigns 6 and 17. first extract light curves two using different pipelines, EVEREST Lightkurve. seismic analysis is done on combined curve C6 C17 where gap between was removed stitched together. determine global...
ABSTRACT Gyrochronology can yield useful ages for field main-sequence stars, a regime where other techniques are problematic. Typically, gyrochronology relations calibrated using young (≲2 Gyr) clusters, but the constraints at older scarce, making them potentially inaccurate and imprecise. In order to test performance of existing relations, we construct samples stellar pairs with coeval components, range available rotation periods. These include randomly paired stars in wide binaries Kepler...
Context. Binary systems constitute a valuable astrophysics tool for testing our understanding of stellar structure and evolution. Systems containing at least one oscillating component are interesting in this regard because asteroseismology offers independent parameters the that aid analysis. particular interest include those with known inclinations. With ∼0.8 million binary candidates, two-body orbit catalog (TBO) Gaia Data Release 3 (DR3) substantially increases number binaries quality...