arXiv - PHYS - Solar and Stellar Astrophysics最新文献

{"title":"Planetary nebulae seen with TESS: New and revisited short-period binary central star candidates from Cycles 1 to 4","authors":"Alba Aller, Jorge Lillo-Box, David Jones","doi":"arxiv-2409.06332","DOIUrl":"https://doi.org/arxiv-2409.06332","url":null,"abstract":"High-precision and high-cadence photometric surveys such as Kepler or TESS\u0000are making huge progress not only in the detection of new extrasolar planets\u0000but also in the study of a great number of variable stars. This is the case for\u0000central stars of planetary nebulae (PNe), which have similarly benefited from\u0000the capabilities of these missions, increasing the number of known binary\u0000central stars and helping us to constrain the relationship between binarity and\u0000the complex morphologies of their host PNe. In this paper, we analyse the TESS\u0000light curves of a large sample of central stars of PNe with the aim of\u0000detecting signs of variability that may hint at the presence of short-period\u0000binary nuclei. We analysed 62 central stars of true, likely, or possible PNe\u0000and modelled the detected variability through an MCMC approach accounting for\u0000three effects: reflection, ellipsoidal modulations, and Doppler beaming. Among\u0000the 62 central stars, only 38 are amenable for this study. The remaining 24\u0000show large contamination from nearby sources preventing an optimal analysis.\u0000Also, eight targets are already known binary central stars, which we revisit\u0000here with the new high precision of the TESS data. In addition, we find that 18\u0000further central stars show clear signs of periodic variability in the TESS\u0000data, probably resulting from different physical effects compatible with the\u0000binary scenario. We propose them as new candidate binary central stars. We also\u0000discuss the origin of the detected variability in each particular case by using\u0000the TESS_localize algorithm. Finally, 12 targets show no or only weak evidence\u0000of variability at the sensitivity of TESS. Our study demonstrates the power of\u0000space-based photometric surveys in searching for close binary companions of\u0000central stars of PNe.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142217387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Doppler velocity of $m=1$ high-latitude inertial mode over the last five sunspot cycles","authors":"Zhi-Chao Liang, Laurent Gizon","doi":"arxiv-2409.06896","DOIUrl":"https://doi.org/arxiv-2409.06896","url":null,"abstract":"Among the identified solar inertial modes, the high-latitude mode with\u0000azimuthal order $m=1$ (HL1) has the largest amplitude and plays a role in\u0000shaping the Sun's differential rotation profile. We aim to study the evolution\u0000of the HL1 mode parameters, utilizing Dopplergrams from the Mount Wilson\u0000Observatory (MWO), GONG, and HMI, covering together five solar cycles since\u00001967. We calculated the averages of line-of-sight Doppler signals over\u0000longitude, weighted by the sine of longitude with respect to the central\u0000meridian, as a proxy for zonal velocity at the surface. We measured the mode's\u0000power and frequency from these zonal velocities at high latitudes in sliding\u0000time windows of three years. We find that the amplitude of the HL1 mode\u0000undergoes very large variations, taking maximum values at the start of solar\u0000cycles 21, 22 and 25, and during the rising phases of cycles 23 and 24. The\u0000mode amplitude is anticorrelated with the sunspot number (corr=$-0.50$) but not\u0000correlated with the polar field strength. Over the period 1983-2022 the mode\u0000amplitude is strongly anticorrelated with the rotation rate at latitude\u0000$60^circ$ (corr=$-0.82$), i.e., with the rotation rate near the mode's\u0000critical latitude. The mode frequency variations are small and display no clear\u0000solar cycle periodicity above the noise level ($sim pm 3$~nHz). Since about\u00001990, the mode frequency follows an overall decrease of $sim 0.25$ nHz/year,\u0000consistent with the long-term decrease of the angular velocity at $60^circ$\u0000latitude. We expect that these very long time series of the mode properties\u0000will be key to constrain models and reveal the dynamical interactions between\u0000the high-latitude modes, rotation, and the magnetic field.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142217405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revealing the elusive companion of the red giant binary 2MASSJ05215658+4359220 from UV HST and Astrosat-UVIT data","authors":"Luciana Bianchi, John Hutchings, Ralph Bohlin, David Thilker, Emanuele Berti","doi":"arxiv-2409.06906","DOIUrl":"https://doi.org/arxiv-2409.06906","url":null,"abstract":"Black hole demographics in different environments is critical in view of\u0000recent results on massive-stars binarity, and of the multi-messenger\u0000detectability of compact objects mergers. But the identification and\u0000characterization of non-interacting black holes is elusive, especially in the\u0000sparse field stellar population. A candidate non-interactive black hole\u0000(BH)+red giant (RG) binary system, 2MASSJ05215658+4359220, was identified by\u0000Thompson et al.(2019). We obtained Astrosat/UVIT Far-Ultraviolet (FUV) imaging\u0000and Hubble Space Telescope (HST) UV-optical imaging and spectroscopy of the\u0000source, to test possible scenarios for the optically-elusive companion.\u0000HST/STIS spectra from about 1,600 to 10,230Ang are best fit by the combination\u0000of two stellar sources, a red giant with Teff=4250 (uncertainty 150K),\u0000logg=2.0, Radius_RG=27.8Rsun (assuming a single-temperature atmosphere), and a\u0000subgiant companion with Teff=6,000K, Radius_comp=2.7Rsun, or Teff=5,270K,\u0000Radius_comp=4.2Rsun using models with one-tenth or one-third solar metallicity\u0000respectively, logg=3.0, extinction E(B-V)=0.50(uncertainty 0.2), adopting the\u0000DR3 Gaia distance D=2,463pc (uncertainty 120pc). No FUV data existed prior to\u0000our programs. STIS spectra give an upper limit of 10e-17ergs cm-2 s-1 Ang-1\u0000shortward of 2300Ang; an upper limit of >25.7ABmag was obtained in two UVIT FUV\u0000broad-bands. The non-detection of FUV flux rules out a compact companion such\u0000as a hot WD. The STIS spectrum shows strong MgII lambda2800Ang emission,\u0000typical of chromospherically active red giants. The masses inferred by\u0000comparison with evolutionary tracks, about 1 Msun for the red giant and between\u00001.1 and 1.6Msun for the subgiant companion, suggest past mass transfer,\u0000although the red giant currently does not fill its Roche lobe. WFC3 imaging in\u0000F218W, F275W, F336W, F475W, and F606W shows an unresolved source in all\u0000filters.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142217380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Fields in a sample of planet-hosting M dwarf stars from Kepler, K2, and TESS observed by APOGEE","authors":"Fábio Wanderley, Katia Cunha, Verne Smith, Oleg Kochukhov, Diogo Souto, Carlos Allende Prieto, Suvrath Mahadevan, Steven Majewski, Philip Muirhead, Marc Pinsonneault, Ryan Terrien","doi":"arxiv-2409.06637","DOIUrl":"https://doi.org/arxiv-2409.06637","url":null,"abstract":"Stellar magnetic fields have a major impact on space weather around\u0000exoplanets orbiting low-mass stars. From an analysis of Zeeman-broadened Fe I\u0000lines measured in near-infrared SDSS/APOGEE spectra, mean magnetic fields are\u0000determined for a sample of 29 M dwarf stars that host closely orbiting small\u0000exoplanets. The calculations employed the radiative transfer code Synmast and\u0000MARCS stellar model atmospheres. The sample M dwarfs are found to have\u0000measurable mean magnetic fields ranging between $sim$0.2 to $sim$1.5 kG,\u0000falling in the unsaturated regime on the $<$B$>$ vs P$_{rm rot}$ plane. The\u0000sample systems contain 43 exoplanets, which include 23 from Kepler, nine from\u0000K2, and nine from TESS. We evaluated their equilibrium temperatures,\u0000insolation, and stellar habitable zones and found that only Kepler-186f and\u0000TOI-700d are inside the habitable zones of their stars. Using the derived\u0000values of $<$B$>$ for the stars Kepler-186 and TOI-700 we evaluated the minimum\u0000planetary magnetic field that would be necessary to shield the exoplanets\u0000Kepler-186f and TOI-700d from their host star's winds, considering reference\u0000magnetospheres with sizes equal to those of the present-day and young Earth,\u0000respectively. Assuming a ratio of 5$%$ between large-to-small scale B-fields,\u0000and a young-Earth magnetosphere, Kepler-186f and TOI-700d would need minimum\u0000planetary magnetic fields of, respectively, 0.05 and 0.24 G. These values are\u0000considerably smaller than Earth's magnetic field of 0.25\u0000G$lesssim$B$lesssim$0.65 G, which suggests that these two exoplanets might\u0000have magnetic fields sufficiently strong to protect their atmospheres and\u0000surfaces from stellar magnetic fields.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142217408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Y Dwarfs: The Challenge of Discovering the Coldest Substellar Population in the Solar Neighborhood","authors":"Sandy K. Leggett","doi":"arxiv-2409.06158","DOIUrl":"https://doi.org/arxiv-2409.06158","url":null,"abstract":"Stars form in the Galaxy with a wide range in mass. If the mass is below 7%\u0000of the Sun's, then the object does not become hot enough for stable hydrogen\u0000burning. These substellar objects are called brown dwarfs. Maps of the sky at\u0000infrared wavelengths have found large numbers of brown dwarfs. However only 24\u0000objects have been found (as of April 2017) that are cold enough to be\u0000classified as \"Y dwarfs\": these have atmospheres that are cooler than 500 K (or\u0000200 C, 400 F) and have masses only 5 - 20 times that of Jupiter. The coolest Y\u0000dwarf currently known, discovered in 2014, has a temperature around freezing,\u0000has a mass of about 5 Jupiter masses, and is only 2 pc away from the Sun. These\u0000small and cold objects are faint and difficult to find. This chapter describes\u0000the discovery and characterization of the Y dwarfs. Finding more of these very\u0000cold planet-like brown dwarfs will require an as-yet unplanned space mission\u0000mapping large areas of sky at wavelengths around 5 microns.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142217406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability and fate of hierarchical triples comprising a central massive body and a tight binary in eccentric orbits","authors":"Toshinori Hayashi, Alessandro A. Trani, Yasushi Suto","doi":"arxiv-2409.06253","DOIUrl":"https://doi.org/arxiv-2409.06253","url":null,"abstract":"We explore the stability and fate of gravitational triple systems comprising\u0000a central massive body and a tight binary of less massive pairs. Our present\u0000purpose is two fold; (1) to improve the Hill-type stability criterion for the\u0000binary in those systems, and (2) to examine the fate of the triple systems\u0000after the binary break-up, with particular attention to the effects of the\u0000eccentricities of the inner and outer orbits. We perform direct Newtonian\u0000N-body simulations over much longer integration times than previous studies,\u0000which is essential to determine the eventual fate of those systems\u0000statistically in a reliable fashion. We obtain an empirical fitting formula of\u0000the binary stability boundary that incorporates effects of the inner and outer\u0000eccentricities, the mutual inclination of the inner and outer orbits, and the\u0000mass ratios of the three bodies. We also find that those triple systems are\u0000stable for a much longer timescale after the binary break-up, and that their\u0000final fates (ejection of the outer body, merger to the central massive body,\u0000and collision of two less massive bodies) are very sensitive to the initial\u0000outer eccentricity.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation and evolution of a protoplanetary disk: combining observations, simulations and cosmochemical constraints","authors":"Alessandro Morbidelli, Yves Marrocchi, Adnan Ali Ahmad, Asmita Bhandare, Sebastien Charnoz, Benoit Commercon, Cornellis P. Dullemond, Tristan Guillot, Patrick Hennebelle, Yueh-Ning Lee, Francesco Lovascio, Raphael Marschall, Bernard Marty, Anaelle Maury, Okamoto Tamami","doi":"arxiv-2409.06342","DOIUrl":"https://doi.org/arxiv-2409.06342","url":null,"abstract":"We present a plausible and coherent view of the evolution of the protosolar\u0000disk that is consistent with the cosmochemical constraints and compatible with\u0000observations of other protoplanetary disks and sophisticated numerical\u0000simulations. The evidence that high-temperature condensates, CAIs and AOAs,\u0000formed near the protosun before being transported to the outer disk can be\u0000explained by either an early phase of vigorous radial spreading of the disk, or\u0000fast transport of these condensates from the vicinity of the protosun towards\u0000large disk radii via the protostellar outflow. The assumption that the material\u0000accreted towards the end of the infall phase was isotopically distinct allows\u0000us to explain the observed dichotomy in nucleosynthetic isotopic anomalies of\u0000meteorites and leads to intriguing predictions on the isotopic composition of\u0000refractory elements in comets. When the infall of material waned, the disk\u0000started to evolve as an accretion disk. Initially, dust drifted inwards,\u0000shrinking the radius of the dust component to ~ 45 au, probably about 1/2 of\u0000the width of the gas component. Then structures must have emerged, producing a\u0000series of pressure maxima in the disk which trapped the dust on My timescales.\u0000This allowed planetesimals to form at radically distinct times without changing\u0000significantly of isotopic properties. There was no late accretion of material\u0000onto the disk via streamers. The disk disappeared in ~5 Myr, as indicated by\u0000paleomagnetic data in meteorites. In conclusion, the evolution of the\u0000protosolar disk seems to have been quite typical in terms of size, lifetime,\u0000and dust behavior, suggesting that the peculiarities of the Solar system with\u0000respect to extrasolar planetary system probably originate from the chaotic\u0000nature of planet formation and not at the level of the parental disk.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142217407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Searching for Stellar Activity Cycles using Flares: The Short and Long Timescale Activity Variations of TIC-272272592","authors":"Tobin M. Wainer, James R. A. Davenport, Guadalupe Tovar Mendoza, Tom Wagg","doi":"arxiv-2409.06631","DOIUrl":"https://doi.org/arxiv-2409.06631","url":null,"abstract":"We examine 4 years of Kepler 30-min data, and 5 Sectors of TESS 2-min data\u0000for the dM3 star KIC-8507979/TIC-272272592. This rapidly rotating (P=1.2 day)\u0000star has previously been identified as flare active, with a possible long-term\u0000decline in its flare output. Such slow changes in surface magnetic activity are\u0000potential indicators of Solar-like activity cycles, which can yield important\u0000information about the structure of the stellar dynamo. We find that while\u0000TIC-272272592 shows evidence for both short and long timescale variations in\u0000its flare activity, it is unlikely physically motivated. Only a handful of\u0000stars have been subjected to such long baseline point-in-time flare studies,\u0000and we urge caution in comparing results between telescopes due to differences\u0000in bandpass, signal to noise, and cadence. In this work, we develop an approach\u0000to measure variations in the flare frequency distributions over time, which is\u0000quantified as a function of the observing baseline. For TIC-272272592, we find\u0000a $2.7sigma$ detection of a Sector which has a flare deficit, therefore\u0000indicating the short term variation could be a result of sampling statistics.\u0000This quantifiable approach to describing flare rate variation is a powerful new\u0000method for measuring the months-to-years changes in surface magnetic activity,\u0000and provides important constraints on activity cycles and dynamo models for low\u0000mass stars.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142217385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovery of a Bow-Shock Nebula around the Z Cam-type Cataclysmic Variable SY Cancri","authors":"Howard E. BondPenn State UniversitySTScI, Calvin CarterDallas, TX, David F. ElmoreNational Solar Observatory, Peter GoodhewDeep Space Imaging Network, Dana PatchickDeep Sky Hunters Consortium, Jonathan TalbotStark Bayou Observatory","doi":"arxiv-2409.06835","DOIUrl":"https://doi.org/arxiv-2409.06835","url":null,"abstract":"We report the serendipitous discovery of a bow-shock nebula around the\u0000cataclysmic variable (CV) SY Cancri. In addition, SY Cnc lies near the edge of\u0000a faint Halpha-emitting nebula with a diameter of about 15'. The orientation of\u0000the bow shock is consistent with the direction of SY Cnc's proper motion.\u0000Nebulae are extremely rare around CVs, apart from those known to have undergone\u0000classical-nova (CN) outbursts; bow shocks and off-center nebulae are even more\u0000unusual. Nevertheless, the properties of SY Cnc and its nebulosity are\u0000strikingly similar to those of V341 Ara, another CV that is also associated\u0000with a bow shock and is likewise off-center with respect to its faint Halpha\u0000nebula. Both stars are binaries with optically thick accretion disks, belonging\u0000to the classes of Z Cam CVs or nova-like variables. We discuss three scenarios\u0000to explain the properties of the nebulae. They may have resulted from chance\u0000encounters with interstellar gas clouds, with the stars leaving in their wakes\u0000material that is recombining after being photoionized by UV radiation from the\u0000CVs. Alternatively, the large nebulae could be ejecta from unobserved CN\u0000outbursts in the recent past, which have been decelerated through collisions\u0000with the interstellar medium (ISM), while the stars continue to snowplow\u0000through the gas. Or the faint Halpha nebulae may be ambient ISM that was\u0000shock-ionized by a CN outburst in the past and is now recombining.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The only inflated brown dwarf in an eclipsing white dwarf-brown dwarf binary: WD1032+011B","authors":"Jenni R. French, Sarah L. Casewell, Rachael C. Amaro, Joshua D. Lothringer, L. C. Mayorga, Stuart P. Littlefair, Ben W. P. Lew, Yifan Zhou, Daniel Apai, Mark S. Marley, Vivien Parmentier, Xianyu Tan","doi":"arxiv-2409.06874","DOIUrl":"https://doi.org/arxiv-2409.06874","url":null,"abstract":"Due to their short orbital periods and relatively high flux ratios,\u0000irradiated brown dwarfs in binaries with white dwarfs offer better\u0000opportunities to study irradiated atmospheres than hot Jupiters, which have\u0000lower planet-to-star flux ratios. WD1032+011 is an eclipsing, tidally locked\u0000white dwarf-brown dwarf binary with a 9950 K white dwarf orbited by a 69.7\u0000M$_{Jup}$ brown dwarf in a 0.09 day orbit. We present time-resolved Hubble\u0000Space Telescope Wide Field Camera 3 spectrophotometric data of WD1032+011. We\u0000isolate the phase-dependent spectra of WD1032+011B, finding a 210 K difference\u0000in brightness temperature between the dayside and nightside. The spectral type\u0000of the brown dwarf is identified as L1 peculiar, with atmospheric retrievals\u0000and comparison to field brown dwarfs showing evidence for a cloud-free\u0000atmosphere. The retrieved temperature of the dayside is $1748^{+66}_{-67}$ K,\u0000with a nightside temperature of $1555^{+76}_{-62}$ K, showing an\u0000irradiation-driven temperature contrast coupled with inefficient heat\u0000redistribution from the dayside to the nightside. The brown dwarf radius is\u0000inflated, likely due to the constant irradiation from the white dwarf, making\u0000it the only known inflated brown dwarf in an eclipsing white dwarf-brown dwarf\u0000binary.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142217381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}