Results 31 to 40 of about 2,970 (266)

WIYN Open Cluster Study 89. M48 (NGC 2548) 2: Lithium Abundances in the 420 Myr Open Cluster M48 from Giants through K Dwarfs

The Astrophysical Journal, 2023
We consider WIYN/Hydra spectra of 329 photometric candidate members of the 420 Myr old open cluster M48 and report lithium detections or upper limits for 234 members and likely members.
Qinghui Sun, Constantine P. Deliyannis, Aaron Steinhauer, Barbara J. Anthony-Twarog, Bruce A. Twarog   +4 more
doaj   +1 more source

THE ORBIT OF THE L DWARF + T DWARF SPECTRAL BINARY SDSS J080531.84+481233.0* [PDF]

The Astrophysical Journal, 2016
ABSTRACT SDSS J080531.84+481233.0 is a closely separated, very-low-mass (VLM) binary identified through combined-light spectroscopy and confirmed as an astrometric variable. Here we report four years of radial velocity monitoring observations of the system that reveal significant and periodic variability, confirming the binary nature of ...
Adam J. Burgasser, Cullen H. Blake, Christopher R. Gelino, Johannes Sahlmann, Daniella Bardalez Gagliuffi   +4 more
openaire   +3 more sources

Euclid: Quick Data Release (Q1) – A photometric search for ultracool dwarfs in the Euclid Deep Fields★

Astronomy & Astrophysics
We present a catalogue of 5306 new ultracool dwarf (UCD) candidates in the three Euclid Deep Fields in the Q1 data release. They range from late M to late T dwarfs, and include 1200 L and T dwarfs.
Žerjal M., Dominguez-Tagle C., Vitas N., Sedighi N., Martín E. L., Zapatero Osorio M. R., Olivares J., Muñoz Torres S., Tsilia S., Zhang J.-Y., Barrado D., Béjar V. J. S., Bouy H., Burgasser A., Cruz P., Lodieu N., Mas Buitrago P., Phan-Bao N., Solano E., Tata R., Goldman B., Mohandasan A., Reylé C., Smart R. L., Aghanim N., Altieri B., Amara A., Andreon S., Auricchio N., Baccigalupi C., Baldi M., Balestra A., Bardelli S., Battaglia P., Biviano A., Bonchi A., Branchini E., Brescia M., Brinchmann J., Camera S., Cañas-Herrera G., Capobianco V., Carbone C., Carretero J., Casas S., Castellano M., Castignani G., Cavuoti S., Chambers K. C., Cimatti A., Colodro-Conde C., Congedo G., Conselice C. J., Conversi L., Copin Y., Courbin F., Courtois H. M., Cropper M., Cuby J.-G., Da Silva A., Degaudenzi H., De Lucia G., Dolding C., Dole H., Douspis M., Dubath F., Dupac X., Dusini S., Escoffier S., Farina M., Faustini F., Ferriol S., Fotopoulou S., Frailis M., Franceschi E., Galeotta S., George K., Gillis B., Giocoli C., Gómez-Alvarez P., Gracia-Carpio J., Granett B. R., Grazian A., Grupp F., Haugan S. V. H., Hoar J., Holmes W., Hormuth F., Hornstrup A., Jahnke K., Jhabvala M., Keihänen E., Kermiche S., Kiessling A., Kubik B., Kuijken K., Kümmel M., Kunz M., Kurki-Suonio H., Le Boulc’h Q., Le Brun A. M. C., Ligori S., Lilje P. B., Lindholm V., Lloro I., Mainetti G., Maino D., Maiorano E., Mansutti O., Marggraf O., Martinelli M., Martinet N., Marulli F., Massey R., Medinaceli E., Mei S., Mellier Y., Meneghetti M., Merlin E., Meylan G., Mora A., Moresco M., Moscardini L., Nakajima R., Neissner C., Niemi S.-M., Padilla C., Paltani S., Pasian F., Pedersen K., Percival W. J., Pettorino V., Pires S., Polenta G., Poncet M., Popa L. A., Pozzetti L., Raison F., Rebolo R., Renzi A., Rhodes J., Riccio G., Romelli E., Roncarelli M., Saglia R., Sakr Z., Sapone D., Sartoris B., Schewtschenko J. A., Schirmer M., Schneider P., Secroun A., Seidel G., Seiffert M., Serrano S., Simon P., Sirignano C., Sirri G., Stanco L., Steinwagner J., Tallada-Crespí P., Taylor A. N., Tereno I., Toft S., Toledo-Moreo R., Torradeflot F., Tsyganov A., Tutusaus I., Valenziano L., Valiviita J., Vassallo T., Verdoes Kleijn G., Veropalumbo A., Wang Y., Weller J., Zacchei A., Zamorani G., Zerbi F. M., Zucca E., Martín-Fleitas J., Scottez V.   +180 more
doaj   +1 more source

THE PHYSICAL PROPERTIES OF FOUR ∼600 K T DWARFS [PDF]

The Astrophysical Journal, 2009
26 pages, including 2 Tables and 9 Figures, accepted for publication in Astrophysical ...
Leggett, S. K., Cushing, Michael C., Saumon, D., Marley, M. S., Roellig, T. L., Warren, S. J., Burningham, Ben, Jones, H. R. A., Kirkpatrick, J. D., Lodieu, N., Lucas, P. W., Mainzer, A. K., Martín, E.L., McCaughrean, M. J., Pinfield, D. J., Sloan, G. C., Smart, R. L., Tamura, M., Van Cleve, J.   +18 more
openaire   +3 more sources

L and T Dwarf Models and the L to T Transition [PDF]

The Astrophysical Journal, 2006
accepted to the Astrophysical Journal, 21 figures (20 in color); spectral models in electronic form available at http://zenith.as.arizona.edu ...
Burrows, Adam, Sudarsky, David, Hubeny, Ivan   +2 more
openaire   +2 more sources

Investigating Possible Binarity for GJ 229B

The Astrophysical Journal Letters, 2023
GJ 229B, the first type-T brown dwarf to be discovered, has presented a tension between comparisons with evolutionary models and the larger-than-expected mass and radius values derived from spectroscopic and astrometric observations.
Alex R. Howe, Avi M. Mandell, Michael W. McElwain   +2 more
doaj   +1 more source

Time-resolved Optical Polarization Monitoring of the Most Variable Brown Dwarf

The Astronomical Journal, 2023
Recent atmospheric models for brown dwarfs suggest that the existence of clouds in substellar objects is not needed to reproduce their spectra, nor their rotationally induced photometric variability, believed to be due to the heterogeneous cloud coverage
Elena Manjavacas, Paulo A. Miles-Páez, Theodora Karalidi, Johanna M. Vos, Max L. Galloway, Julien H. Girard   +5 more
doaj   +1 more source

The 2MASS Wide-Field T Dwarf Search. II. Discovery of Three T Dwarfs in the Southern Hemisphere [PDF]

The Astronomical Journal, 2003
We present the discovery of three new Southern Hemisphere T dwarfs identified in the Two Micron All Sky Survey. These objects, 2MASS 0348-6022, 2MASS 0516-0445, and 2MASS 2228-4310, have classifications T7, T5.5, and T6.5, respectively. Using linear absolute magnitude/spectral type relations derived from T dwarfs with measured parallaxes, we estimate ...
Burgasser, Adam J., McElwain, Michael W., Kirkpatrick, J. Davy   +2 more
openaire   +2 more sources

Microbiome‐blood–brain barrier interactions in aging — mechanisms and therapeutic potential

FEBS Letters, EarlyView.
Aging reshapes the gut microbiome (↓SCFA‐producing commensals; ↑pro‐inflammatory outputs), shifting circulating metabolites (↓SCFAs; ↑LPS, ↑TMAO, ↑PAA) that act at the BBB to increase nonspecific transcytosis, alter transport, and promote astrocyte reactivity, heightening brain vulnerability.
Daniel Cuervo‐Zanatta, Hari Baskar Balasubramanian, Amir Pasokh, Marietta Zille   +3 more
wiley   +1 more source

The Coldest Known Y Dwarfs: Estimates of Their Effective Temperatures

The Astrophysical Journal
For a decade there has been a factor of 2.5 gap in luminosity between the 275 K WISE J085510.83-071442.5 and all other Y dwarfs, with T _eff  ≳ 350 K. Recently, three objects were found that may fall in this gap.
S. K. Leggett
doaj   +1 more source