Related Experiment Video
Updated: Apr 14, 2026

Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
The first extragalactic ultra-compact X-ray binary: A candidate black hole-white dwarf system.
Qian-Qi Ma1, Jiachang Zhang2,3, Wei-Min Gu1
1Department of Astronomy, Xiamen University, Xiamen, Fujian 361005, China.
M31 UCXB-1 is the brightest ultra-compact X-ray binary (UCXB) discovered, likely a black hole-white dwarf system. It exhibits the shortest orbital period and strongest gravitational wave emission among known UCXBs.
Area of Science:
- * Astrophysics
- * High-energy astrophysics
- * Compact objects
Background:
- * M31 UCXB-1 is a luminous X-ray source in the M31 galaxy.
- * It exhibits an eclipsing signal suggesting an ultra-compact X-ray binary (UCXB).
Purpose of the Study:
- * To investigate the nature of M31 UCXB-1.
- * To determine its classification as a black hole/neutron star-white dwarf (BH/NS-WD) UCXB.
Main Methods:
- * Analysis of XMM-Newton and Chandra X-ray observations.
- * Theoretical modeling of luminosity-orbital period relations.
- * Spectral analysis to determine the primary object's nature.
Main Results:
- * M31 UCXB-1 displays a high X-ray luminosity and a 465 s orbital period.
- * The source aligns with the BH/NS-WD UCXB luminosity-orbital period relation.
- * Spectral analysis favors a black hole primary over a neutron star.
Conclusions:
- * M31 UCXB-1 is identified as a black hole-white dwarf (BH-WD) system.
- * It possesses the shortest orbital period and potentially strongest gravitational wave emission among known UCXBs.
- * The system likely hosts the most massive white dwarf discovered in UCXBs.
More Related Videos
12:14The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry
Published on: August 12, 2013
11:27Studying Soft-matter and Biological Systems over a Wide Length-scale from Nanometer and Micrometer Sizes at the Small-angle Neutron Diffractometer KWS-2
Published on: December 8, 2016
Related Concept Videos
Detection of Black Holes
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Schwarzschild Radius and Event Horizon
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...
Reduced Mass Coordinates: Isolated Two-body Problem
Gravitation Between Spherically Symmetric Masses
Conservation of Angular Momentum: Application
X-ray Imaging