Results 71 to 80 of about 241,576 (378)

An HST Study of the Substellar Population of NGC 2024

The Astrophysical Journal, 2023
We performed an HST/WFC3-IR imaging survey of the young stellar cluster NGC 2024 in three filters probing the 1.4 μ m H _2 O absorption feature, characteristic of the population of low-mass and substellar-mass objects down to a few Jupiter masses.
Massimo Robberto, Mario Gennaro, Nicola Da Rio, Giovanni Maria Strampelli, Leonardo Ubeda, Elena Sabbi, Dana Koeppe, Jonathan C. Tan, David R. Soderblom   +8 more
doaj   +1 more source

The effect of accretion on the pre-main-sequence evolution of low-mass stars and brown dwarfs [PDF]

, 2017
The pre-main-sequence evolution of low-mass stars and brown dwarfs is studied numerically starting from the formation of a protostellar/proto-brown dwarf seed and taking into account the mass accretion onto the central object during the initial several ...
E. Vorobyov, V. Elbakyan, T. Hosokawa, Y. Sakurai, M. Guedel, Harold Yorke Institute of Fluid Mechanics, Heat Transfer Research Institute of Physics, Southern Federal University, R. Vienna, Department of Applied Physics, Kyoto Sangyo University Department of Physics, Graduate School of Science, T. L. H. J. P. Laboratory, C. I. O. Technology.   +13 more
semanticscholar   +1 more source

The pre-main-sequence star IP Persei [PDF]

Astronomy & Astrophysics, 2001
We present the results of high- and low-resolution spectroscopic and broadband multicolour photometric observations of the emission-line A-type star IP Per. Significant variations of the Balmer line profiles and near-IR brightness are detected.
A. S. Miroshnichenko, K. S. Bjorkman, E. L. Chentsov, V. G. Klochkova, R. O. Gray, P. García-Lario, J. V. Perea Calderón   +6 more
openaire   +1 more source

New periodic variable stars coincident with ROSAT sources discovered using SuperWASP [PDF]

, 2007
We present optical lightcurves of 428 periodic variable stars coincident with ROSAT X-ray sources, detected using the first run of the SuperWASP photometric survey. Only 68 of these were previously recognised as periodic variables.
A. Collier Cameron, A. J. Norton, Akerlof, Alekseev, Alekseev, B. Enoch, Bejgman, Boller, Bouvier, Bouvier, Bouvier, Brancewicz, Brelstaff, C. A. Haswell, C. Hellier, Chrastina, Collier Cameron, Collier Cameron, D. J. Christian, D. M. Wilson, D. Pollacco, Deeter, Dempsey, Engle, Evans, Feast, Gershberg, Hall, Hall, Hartmann, I. Skillen, J. Irwin, J. P. Nicholas, Jeffries, K. Horne, Koen, Loomis, M. Gallaway, Meinunger, Monet, N. Parley, Neuhauser, P. J. Wheatley, Pallavicini, Pettersen, Pizzolato, Pribulla, Qian, R. A. Street, R. G. West, R. Ryans, Rosner, S. R. Kane, Schmidt, Schmidt, Selam, Skillen, Stanishev, Strassmeier, T. A. Lister, Tamuz, Turner, Vilhu, W. I. Clarkson, Walter, Wegner, Wheatley, Zhang   +67 more
core   +3 more sources

Cool stars in NGC 2547 and pre main sequence lithium depletion [PDF]

, 2003
We present the results of a spectroscopic survey of X-ray selected, low-mass candidate members of the young open cluster NGC 2547. Using a combination of photometry, spectroscopic indices and radial velocities we refine our candidate list and then use ...
Jeffries, R. D, Navascues, D. Barrado y, Oliveira, J. M., Stauffer, J. R.   +3 more
core   +2 more sources

By dawn or dusk—how circadian timing rewrites bacterial infection outcomes

FEBS Letters, EarlyView.
The circadian clock shapes immune function, yet its influence on infection outcomes is only beginning to be understood. This review highlights how circadian timing alters host responses to the bacterial pathogens Salmonella enterica, Listeria monocytogenes, and Streptococcus pneumoniae revealing that the effectiveness of immune defense depends not only
Devons Mo, Catherine S. Palmer, Jacqueline M. Kimmey   +2 more
wiley   +1 more source

Peptide‐based ligand antagonists block a Vibrio cholerae adhesin

FEBS Letters, EarlyView.
The structure of a peptide‐binding domain of the Vibrio cholerae adhesin FrhA was solved by X‐ray crystallography, revealing how the inhibitory peptide AGYTD binds tightly at its Ca2+‐coordinated pocket. Structure‐guided design incorporating D‐amino acids enhanced binding affinity, providing a foundation for developing anti‐adhesion therapeutics ...
Mingyu Wang, Grace Du, Charity Yongo‐Luwawa, Angelina Lu, Brett Kinrade, Kim Munro, Karl E. Klose, William D. Lubell, Peter Davies, Shuaiqi Guo   +9 more
wiley   +1 more source

Interplay between circadian and other transcription factors—Implications for cycling transcriptome reprogramming

FEBS Letters, EarlyView.
This perspective highlights emerging insights into how the circadian transcription factor CLOCK:BMAL1 regulates chromatin architecture, cooperates with other transcription factors, and coordinates enhancer dynamics. We propose an updated framework for how circadian transcription factors operate within dynamic and multifactorial chromatin landscapes ...
Xinyu Y. Nie, Jerome S. Menet
wiley   +1 more source

H2 and CO Emission from Disks around T Tauri and Herbig Ae Pre-Main-Sequence Stars and from Debris Disks around Young Stars: Warm and Cold Circumstellar Gas [PDF]

, 2001
We present ISO Short-Wavelength Spectrometer observations of H2 pure-rotational line emission from the disks around low- and intermediate-mass pre-main-sequence stars as well as from young stars thought to be surrounded by debris disks.
W. Thi, E. V. Dishoeck, G. Blake, G. V. Zadelhoff, J. Horn, E. Becklin, V. Mannings, A. Sargent, M. E. V. D. Ancke, A. Natta, J. K. L. Observatory, The Netherlands., C. I. O. Technology., USA., D. Physics, Astronomy, Ucla, H. C. F. Astrophysics, O. Arcetri, Italy   +19 more
semanticscholar   +1 more source

Real‐time assay of ribonucleotide reductase activity with a fluorescent RNA aptamer

FEBS Letters, EarlyView.
Ribonucleotide reductases (RNR) synthesize DNA building blocks de novo, making them crucial in DNA replication and drug targeting. FLARE introduces the first single‐tube real‐time coupled RNR assay, which enables isothermal tracking of RNR activity at nanomolar enzyme levels and allows the reconstruction of allosteric regulatory patterns and rapid ...
Jacopo De Capitani, Noemi E. Nwosu, Viktoria Gocke, Müge Kasanmascheff, Hannes Mutschler   +4 more
wiley   +1 more source