Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>Kepler high cadence data are used to measure the orbital periods and to determine the orbital waveforms of five dwarf novae. A significant improvement of the period of V1504 Cyg is achieved, while for the other systems periods are derived which are compatible with previous determinations. The orbital waveforms of the short period systems V1504 Cyg, V344 Lyr and V516 Lyr are very nearly sinusoidal, while the longer period dwarf nova V447 Lyr appears almost to be a twin of U Gem. The unusual system KIC 9202990 exhibits distinct variations of its waveform as a function of brightness during its outburst cycle.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present the optimal resolution and optimal depth <jats:italic>U</jats:italic>-filter mosaics using the seeing-sorted method of Ashcraft et al. on deep, ground-based <jats:italic>U</jats:italic>-bandimaging of the Great Observatories Origins Deep Survey South field as part of the near-UV imaging program UVCANDELS. We use the <jats:italic>U</jats:italic>-bandimages obtained with the VIsible Multi-Object Spectrograph on the European Southern Observatory Very Large Telescope by Nonino et al. Our best resolution mosaic includes images with a seeing full-width half maximum (FWHM) ≤ 0.″8, and encompasses 50% of the data. Our best depth mosaic includes images with FWHM ≤ 1.″5, corresponding to 100% of the data. Prior to being combined, the source fluxes in each individual background-subtracted image are corrected to match a 3D-HST photometric catalog of the same field to correct variations in the <jats:italic>U</jats:italic>-band zero-points. These mosaics provide deep <jats:italic>U</jats:italic>-banddata complementary to the UVCANDELS HST WFC3 F275W and ACS F435W images. We assess the depth of both <jats:italic>U</jats:italic>-bandmosaics.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The transition from supernovae (SNe) to supernova remnants (SNRs) remains poorly understood, given the age gap between well-studied examples of the two. In order to bridge this gap, we analyzed archival Chandra data for some of the oldest supernovae detected in X-rays, in order to extend their light curves out to late times. We fitted the spectra with thermal models. All the SNe with multiple X-ray data points were found to have similar X-ray luminosity, which was decreasing with time. The X-ray luminosity will likely continue to decrease while the SNe are evolving in a wind medium, but is anticipated to increase in the Sedov phase when the SNe are interacting with a constant density interstellar medium, bringing it in line with observed SNRs</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We update the Bayesian analysis of sunspot numbers (SSNs) developed by Yu et al. prior to the peak of Solar Cycle 24 to account for the recalibration of the SSN index. We show that the model yields an accurate hindcast of Cycle 24 with the revised SSN, and use the data acquired since then to predict the strength and peak of Cycle 25. We predict the behavior of Cycle 25 to be moderate to weak, with a peak SSN of 120±27 to occur c. 2025 July (±7 months).</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Evidence is presented for the presence of a transient emission feature at 1524 Å in the far ultraviolet spectrum of 21 Com recorded by the International Ultraviolet Explorer during the 1979 event. This event is characterized by he sudden appearance of broad and intense absorption features shortwards of 1720 Å. The emission feature at 1524 Å is tentatively identified as a Si <jats:sc>i</jats:sc> line also present in the FUV spectra of quiescent dMe dwarfs. During the event, the flux level in the continuum adjacent to this line is about 1.6 times higher than in the mean spectrum outside event.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Stars do not remain static, so their habitable zones evolve in time. Over a star's evolution, its habitable zone encompasses new planets, and it remains uncertain whether these planets can become habitable. We refer to this often overlooked class of planets as lying in the <jats:italic>belatedly habitable zone</jats:italic>, and stress that many planets found in the habitable zones of other stars will belong to this class. Future studies should take belated habitability into account and not implicitly assume that these planets are habitable.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The 23 Myr system V1298 Tau hosts four transiting planets and is a valuable laboratory for exploring the early stages of planet evolution soon after formation of the star. We observe the innermost planet, V1298 Tau c, during transit using LBT PEPSI to obtain high spectral resolution characterization of escaping material near the H-<jats:italic>α</jats:italic> line. We find no strong evidence for atmospheric material escaping at the orbital velocity of the planet. Instead, we find a deep stellar feature that is variable on the few percent level, similar to a previous observation of the planet and can be explained by stellar activity. We attempted to monitor the broadband optical transit with LBT MODS but do not achieve the precision needed to characterize the atmosphere or improve the ephemeris.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present the discovery of a low-mass comoving system found by means of the NOIRLab Source Catalog DR2. The system consists of the high proper-motion star LEHPM 5005 and an ultracool companion 2MASS J22410186-4500298 with an estimated spectral type of L2. The primary (LEHPM 5005) is likely a mid-M dwarf but over-luminous for its color, indicating a possible close equal mass binary. According to the Gaia EDR3 parallax of the primary, the system is located at a distance of 58 ± 2 pc. We calculated an angular separation of 7.″2 between both components, resulting in a projected physical separation of 418 au.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Hubble Space Telescope photometry of <jats:italic>η</jats:italic> Carinae spans 23 yr, including five spectroscopic events. The rapid brightening rate decreased after 2010, and the spectroscopic events in 2014 and 2020 had light curves different from their predecessors. Together with other indicators, these developments probably foretell the conclusion of <jats:italic>η</jats:italic> Car’s change of state.</jats:p>