Related Experiment Video
Updated: Jul 12, 2026
11:59
Detection of Residual Donor Erythroid Progenitor Cells after Hematopoietic Stem Cell Transplantation for Patients with Hemoglobinopathies
Published on: September 6, 2017
A brown dwarf mass donor in an accreting binary
S P Littlefair1, V S Dhillon, T R Marsh
1Department of Physics and Astronomy, University of Sheffield, S3 7RH, UK. s.littlefair@shef.ac.uk
Science (New York, N.Y.)
|December 13, 2006
Summary
Researchers discovered a brown dwarf donor star in a binary system, confirming a key prediction of stellar evolution. This finding helps refine models of substellar objects in binary systems.
Area of Science:
- * Astronomy and astrophysics
- * Stellar evolution and binary systems
Background:
- * Binary star evolution theory predicts white dwarfs accreting from substellar donors.
- * Such systems are difficult to detect due to challenges in observing low-mass donor stars against bright accretion. No substellar donor mass has been accurately measured previously.
Purpose of the Study:
- * To verify the existence of white dwarf systems with substellar donor stars.
- * To accurately measure the mass of an unseen donor star in an eclipsing binary system.
Main Methods:
- * Application of a specialized technique for mass measurement in eclipsing binary systems.
- * Reliable measurement of the mass of an unobserved donor star.
Main Results:
- * Identification of a brown dwarf donor star with a mass of 0.052 ± 0.002 solar masses.
- * The donor star's mass is relatively high for its orbital period.
Conclusions:
- * The discovery confirms a long-standing prediction in binary star evolution.
- * Current evolutionary models may need revision, potentially underestimating brown dwarf radii.
Related Concept Videos
01:21Schwarzschild Radius and Event Horizon
No object with a finite mass can travel faster than the speed of light in a vacuum. This fact has an interesting consequence in the domain of extremely high gravitational fields.
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape velocity with the...
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape velocity with the...
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
01:14Gravitation Between Spherically Symmetric Masses
The gravitational potential energy between two spherically symmetric bodies can be calculated from the masses and the distance between the bodies, assuming that the center of mass is concentrated at the respective centers of the bodies.
01:12Reduced Mass Coordinates: Isolated Two-body Problem
In classical mechanics, the two-body problem is one of the fundamental problems describing the motion of two interacting bodies under gravity or any other central force. When considering the motion of two bodies, one of the most important concepts is the reduced mass coordinates, a quantity that allows the two-body problem to be solved like a single-body problem. In these circumstances, it is assumed that a single body with reduced mass revolves around another body fixed in a position with an...
01:15Blood Transfusion
Blood transfusion is a critical medical procedure that saves lives and treats various medical conditions. It involves transferring blood from a donor to a recipient. This process requires a thorough understanding of the ABO blood group system and its associated antigens and antibodies.
Blood Transfusion Overview
A blood transfusion is a medical procedure used to replace blood lost due to injury, surgery, or to treat conditions such as anemia or cancer. During a transfusion, donor blood is...
Blood Transfusion Overview
A blood transfusion is a medical procedure used to replace blood lost due to injury, surgery, or to treat conditions such as anemia or cancer. During a transfusion, donor blood is...
01:22Bone Marrow Sampling and Transplants
Bone marrow transplant is a potential cure for several diseases, including cancer and specific genetic disorders. Notably, this procedure is applicable for patients suffering from aplastic anemia, certain types of leukemia, severe combined immunodeficiency disease (SCID), Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, thalassemia, sickle-cell disease, and certain cancers.
The transplant begins with high doses of chemotherapy and radiation treatment, which aim to destroy the...
The transplant begins with high doses of chemotherapy and radiation treatment, which aim to destroy the...