Periodic increases in luminosity arising from variable accretion rates have been predicted for some pre-main-sequence close binary stars as they grow from circumbinary disks. The phenomenon is known as pulsed accretion and can affect the orbital evolution and mass distribution of young binaries, as well as the potential for planet formation. Accretion variability is a common feature of young stars, with a large range of amplitudes and timescales as measured from multi-epoch observations at optical and infrared wavelengths. Periodic variations consistent with pulsed accretion have been seen in only a few young binaries via optical accretion tracers, albeit intermittently with accretion luminosity variations ranging from zero to 50 per cent from orbit to orbit. Here we report that the infrared luminosity of a young protostar (of age about 10(5) years) increases by a factor of ten in roughly one week every 25.34 days. We attribute this to pulsed accretion associated with an unseen binary companion. The strength and regularity of this accretion signal is surprising; it may be related to the very young age of the system, which is a factor of ten younger than the other pulsed accretors previously studied.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1038/nature11746 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Fluid resuscitation strategy in patients with placenta previa accreta: a retrospective study.
Front Med (Lausanne)
September 2024
Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.
Article Synopsis
- Obstetric hemorrhage is a leading cause of maternal death, with placenta previa accreta being a significant factor, contributing to 66% of such cases requiring fluid resuscitation.
- The study retrospectively examined risk factors, clinical features, and outcomes by analyzing hemodynamic indicators related to patients diagnosed with placenta previa accreta over key time points during medical procedures.
- Key findings indicate that conditions like placenta increta/percreta and delivering after 37 weeks significantly increase the risk of massive hemorrhage in these patients, highlighting the need for effective monitoring and fluid management strategies.
A carefully planned resistance training program improves strength, fitness and depressive symptoms for a woman with type 2 diabetes.
Endocrinol Diabetes Metab Case Rep
October 2024
College of Health Solutions, Arizona State University, Phoenix Campus, Phoenix, Arizona, USA.
Article Synopsis
- Depression rates in individuals with type 2 diabetes (T2D) are significantly higher (50%) compared to the general US adult population (18%), alongside increased inflammation markers linked to hyperglycemia.
- A case report highlighted a 59-year-old sedentary woman with T2D and depression, who underwent an 8-week structured resistance training program, leading to a 135% increase in strength and a reduction in depressive symptoms.
- Despite improvements in strength, fitness, and mental health, the resistance training did not affect key diabetes markers (HbA1c, HOMA-IR, or inflammation), highlighting the importance of integrating exercise into a broader treatment strategy for T2D management.
Effects of hemp supplementation during resistance training in trained young adults.
Eur J Appl Physiol
April 2024
College of Kinesiology, University of Saskatchewan, Saskatoon, SK, S7N 5B2, Canada.
Purpose: Hemp contains protein with high concentrations of the branched-chain amino acids leucine, isoleucine, and valine and oils that have anti-inflammatory properties. Our purpose was to investigate the effects of hemp supplementation during resistance training in trained young adults.
Methods: Males (n = 22, 29 ± 8y) and females (n = 12, 30 ± 9y) were randomized (double-blind) to receive 60 g/d of hemp (containing 40 g protein and 9 g oil) or 60 g/d of soy (matched for protein and calories) during eight weeks of resistance training (~ 4x/week).
Impact of ergot alkaloid and steroidal implant on whole-body protein turnover and expression of mTOR pathway proteins in muscle of cattle.
Front Vet Sci
April 2023
Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States.
Introduction: Holstein steers ( = 32) were used to determine if the ergot analog, bromocriptine decreases muscle protein synthesis through inhibitory action on the mTOR pathway a direct effect on signal proteins, and if these negative effects can be alleviated with anabolic agents.
Methods: Steers were treated with intramuscular administration of bromocriptine (vehicle or 0.1 mg/kg BW) and a subdermal commercial steroidal implant containing trenbolone acetate (TBA) and estradiol 17β (with or without), in a 2×2 factorial design.
The use of inorganic ferrous-ferric oxide nanoparticles to improve fresh and durability properties of foamed concrete.
Chemosphere
March 2023
Faculty of Civil Engineering and Built Environment, Universiti Tun Hussein Onn Malaysia (UTHM), Malaysia.
Efforts to modify cement-based mixtures have continuously engrossed the interest of academics. Favourable impacts of nanoparticles, for instance, fine particle size and great reactivity, have made them be utilized in concrete. Foamed concrete (FC) is immensely porous, and its properties diminish with an increase in the number of pores.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!