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Hulse and Taylor won the Nobel Prize in 1993 for the discovery of the first binary pulsar in 1974. It has a period of 59 milliseconds but shows an orbital period of 7 hours and 45 minutes. Discovered at Arecibo, it was an important test of general relativity. There have been about 40 binary pulsars discovered to date.

An exciting close binary was reported in Nature in December 2003 and in Science in early 2004. With the cumbersome designation PSR J0737-3039A, it is composed of pulsars with an eccentric orbit of period just 2.4 hours! The most active of the pulsars spins 44 times per second and its companion just once in 2.8 seconds. Irion in Science described the pair as "two pulsars in a tight orbital embrace, blasting each other with radiation as they spiral toward a mutual doom." General relativity calculations reportedly suggest a convergence of the two pulsars by about 7 millimeters/day with a projected crash in about 85 million years.

At just 2000 light years distance, this binary pulsar is relatively close. It's orbit is almost edge-on from the Earth, optimum for viewing. Part of the promise of this dramatic pair is information about relativistic theories of the gravitational interaction. The discovery of this binary pulsar is credited to the 64-meter Parkes radio telescope in New South Wales, Australia. The measurement of the slower period of the companion is credited to Jodrell Bank Observatory in Macclesfield, U.K.

Cham wrote:The addon is finished (can you confirm ?).
Install into you Extras folder, type PSR J0737-3039 AB in Celestia, then go !
Feedback would be appreciated.

Cham wrote:Ooops ! Just a small correction to the STC file. I forgot to include the mass ratio. Paste this code over the STC code :

Code: Select all

Barycenter "PSR J0737-3039 AB"
{
   RA   114.46353
   Dec   -30.66132
   Distance 1858
}

900121 "PSR J0737-3039A"   # Mass = 1.337 Solar
{
   Texture "Pulsar.jpg"
   OrbitBarycenter "PSR J0737-3039 AB"
   SpectralType "Q"
   AbsMag 27

        EllipticalOrbit
   {
                Period      0.00027379257475 # 2.4 hours
                SemiMajorAxis   0.0025838778 # mass ratio 1.337 : 1.250
                Eccentricity   0.09
                Inclination   0
                AscendingNode   0
                ArgOfPericenter   0
                MeanAnomaly   0
        }

   RotationPeriod 6.30538293226389E-06  # 0.023 sec
}

900122 "PSR J0737-3039B"   # Mass = 1.250 Solar
{
   Texture "Pulsar.jpg"
   OrbitBarycenter "PSR J0737-3039 AB"
   SpectralType "Q"
   AbsMag 27

        EllipticalOrbit
   {
                Period      0.00027379257475 # 2.4 hours
                SemiMajorAxis   0.0027637157 # mass ratio 1.337 : 1.250
                Eccentricity   0.09
                Inclination   0
                AscendingNode   0
                ArgOfPericenter   0
                MeanAnomaly   180
        }

   RotationPeriod 7.70405763166667E-04  # 2.8 sec
}


Jeam Tag wrote: And it seems to me the jets don't touch the star -beginning is obscure (?§a se dit?)

selden wrote:Unfortunately, the url
http://nho.ohn.free.fr/celestia/Cham/PSRJ0737-3039.zip
downloads a zip file which contains the old models with uppercase filetypes.

Cham wrote:Chuft-Captain,

the jets on your picture are perfectly ok. This is what I designed. The video do not came from Celestia ! It's just an "artistic" video from some web site about that pulsars binary.