page:  = <unk> <unk> b = 
   
   <unk> <unk> b ( abbreviated <unk> <unk> b , <unk> And b ) , occasionally designated <unk> <unk> <unk> ( to distinguish it from the red dwarf <unk> <unk> B ) , also named <unk> , is an extrasolar planet approximately 44 light @-@ years away from the Sun in the constellation of <unk> . The planet orbits the Solar twin star , <unk> <unk> A , approximately every five days . Discovered in June 1996 by Geoffrey <unk> and R. Paul Butler , it was one of the first hot Jupiters to be discovered . It is also one of the first non @-@ resolved planets to be detected directly . <unk> <unk> b is the innermost known planet in its planetary system . 
   In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars . The process involved public nomination and voting for the new names . In December 2015 , the IAU announced the winning name was <unk> for this planet . The winning name was submitted by the Vega <unk> Club of Morocco and honours the 11th Century astronomer Ibn al @-@ <unk> of Muslim Spain . 
   
   = = Discovery = = 
   
   Like the majority of known extrasolar planets , <unk> <unk> b was detected by the variations in its star 's radial velocity caused by the planet 's gravity . The variations were detected by making sensitive measurements of the <unk> shift of <unk> <unk> 's spectrum . The planet 's existence was announced in January 1997 , together with 55 <unk> b and the planet orbiting <unk> <unk> . 
   Like 51 <unk> b , the first extrasolar planet discovered around a normal star , <unk> <unk> b orbits very close to its star , closer than Mercury does to our Sun . The planet takes 4 @.@ <unk> days to complete an orbit , with a <unk> axis of 0 @.@ <unk> AU . 
   A limitation of the radial velocity method used to detect <unk> <unk> b is that only a lower limit on the mass can be found . In the case of <unk> <unk> b , this lower limit is 68 @.@ 7 % of the mass of Jupiter , though depending on the inclination of the orbit , the true mass may be much greater . However , astronomers found recently that inclination of the orbital plane is around 25 ° and the true mass may be about 1 @.@ 4 MJ . <unk> is not to be assumed ; the mutual inclination between c and d is 35 degrees . 
   
   = = Physical characteristics = = 
   
   Given the planet 's high mass , it is likely that <unk> <unk> b is a gas giant with no solid surface . 
   The <unk> Space Telescope measured the planet temperature , and found that the difference between the two sides of <unk> <unk> b of about 1 @,@ 400 degrees <unk> , ranging from minus 20 to 230 degrees to about 1 @,@ 400 to 1 @,@ 650 degrees <unk> . The temperature difference has led to speculation that <unk> <unk> b is <unk> locked with the same side always facing <unk> <unk> A. 
   <unk> had , on the assumption that the planet is similar to Jupiter in composition and that its environment is close to chemical equilibrium , predicted <unk> <unk> b to have reflective clouds of <unk> and iron in its upper atmosphere . The cloud deck instead absorbs the sun 's radiation ; between that and the hot , high pressure gas surrounding the mantle , exists a <unk> of cooler gas . The outer shell of dark , <unk> , hot cloud is assumed to consist of <unk> and <unk> oxides ( " <unk> planets " ) , but other compounds like <unk> cannot be ruled out yet . 
   The planet is unlikely to have large moons , since <unk> forces would either <unk> them from orbit or destroy them on short <unk> compared to the age of the system . 
   The planet ( with 51 <unk> b ) was deemed a candidate for direct imaging by <unk> . Preliminary results from <unk> studies indicate that the planet has predominately blue color , is 1 @.@ 36 times as large and 0 @.@ 74 times as massive as Jupiter , meaning that the mean density is <unk> / cm3 . It has a <unk> albedo of 0 @.@ 35 in visible light . 
   
   = = <unk> on its sun = = 
   
   <unk> <unk> b appears to be responsible for increased <unk> activity on its parent star . Observations suggest that there is a " hot spot " on the star around 169 ° away from the sub @-@ planetary point . This may be the result of interactions between the magnetic fields of the planet and the star . The mechanism may be similar to that responsible for the activity of <unk> <unk> <unk> variable stars , or the interaction between Jupiter and its moon Io . 
   
   