HD 172555

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Stern
HD 172555
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation peacock
Right ascension 18 h 45 m 26.9 s
declination -64 ° 52 ′ 16.5 ″
Apparent brightness 4.78 likes
Typing
B − V color index +0.20 
U − B color index +0.08 
Spectral class A7 V
Astrometry
Radial velocity (2.0 ± 4.2) km / s
parallax (35.03 ± 0.19)  mas
distance (93.11 ± 0.51)  Lj
(28.55 ± 0.15)  pc  
Visual absolute brightness M vis +2.5 mag
Proper movement 
Rec. Share: (+32.40 ± 0.17)  mas / a
Dec. portion: (−149.48 ± 0.17)  mas / a
Physical Properties
Age approx. 12 mill.  a
Other names
and catalog entries
Bright Star Catalog HR 7012 [1]
Henry Draper Catalog HD 172555 [2]
Hipparcos catalog HIP 92024 [3]
SAO catalog SAO 254358 [4]
Tycho catalog TYC 9077-2487-1 [5]Template: Infobox star / maintenance / specification of the TYC catalog
Other names FK5  3489

HD 172555 is a star of spectral class A5 V, which lies a little more than 90 light years from Earth in the direction of the constellation Peacock .

Spectral analysis suggests that a recent collision occurred between two of the star's planets, with the smaller of the two being destroyed. This was about the size of the Earth's moon, the other about the size of Mercury. NASA was able to prove the collision with the Spitzer Space Telescope when evaluating a picture taken in 2004.

Artist's impression of the collision between the planets

Individual evidence

  1. ↑ a b c Hipparcos catalog (ESA 1997)
  2. ↑ a b Bright Star Catalog
  3. ↑ Pulkovo radial velocities for 35493 HIP stars
  4. ↑ a b c Hipparcos, the New Reduction (van Leeuwen, 2007)
  5. ↑ calculated from apparent brightness and distance
  6. ^ When Worlds Collide Discover Magazine , Aug. 10, 2009
  7. ↑ Planetary collision in HD 172555 (Raumfahrer.net)