RX J0822-4300

From Wikipedia, the free encyclopedia

**RX J0822-4300**
Observation data Epoch 1952 (equinox J2000.0)^[1]
X-ray image of the Cosmic Cannonball in Puppis A
Constellation (pronunciation)	Puppis
Right ascension	08^h 23^m 8.16^s^[2]
Declination	-42° 41′ 41.4″^[2]
Apparent magnitude (V)	~24^[2]
Characteristics
U-B color index	?
B-V color index	?
Variable type	None
Astrometry
Radial velocity (R_v)	1500.0 km/s
Distance	7.000 Ly
Galactic coordinates	260.3841 -03.4718
Details
Mass	? M_☉
Radius	? R_☉
Luminosity	? L_☉
Temperature	? K
Metallicity	?
Rotation	?
Age	? years
Other designations
EQ 0820-4250, PSR J0822-4300, 1RXS J082158.2-430022.

RX J0822-4300, often referred to as a "Cosmic Cannonball", is a radio-quiet neutron star currently moving away from the center of the Puppis A supernova remnant at over 3 million miles per hour (~0.5% the speed of light), making it one of the fastest moving stars ever found. Astronomers used NASA's Chandra X-ray Observatory to observe the star over a period of five years to determine its speed. At this velocity the star will be ejected from the galaxy millions of years from now.

Although the cosmic cannonball is not the only "hypervelocity star" discovered, it is unique in the apparent origin of its speed. Others may have derived theirs from a gravitational slingshot around the Milky Way's suspected supermassive black hole, Sagittarius A*. Current theories fail to explain how such speeds can be attained from a supernova explosion. It could be a possible quark star.

[edit] See also

Puppis A ou SNR 260.4-3.4

[edit] References

^ [1], C. Y. Hui and W. Becker, Probing the proper motion of the central compact object in Puppis-A with the Chandra high resolution camera
^ ^a ^b ^c [2], C. Y. Hui and W. Becker, X-ray observations of RX J0822-4300 and Puppis-A