Pulsars PSR J0737-3039 A and B binary !

[Cham]

EDIT : Link to actual addon :

http://nho.ohn.free.fr/celestia/Cham/PSRJ0737-3039.zip




I'm starting a new small addon project about extreme pulsars. Let me present you PSR J0737-3039 A and B, husband and wife in real life !

Video link :
http://www.jb.man.ac.uk/news/doublepuls ... 20x256.mpg
Take note : that video is coming from a web site about those pulsars. It's NOT from Celestia !

From the internet :

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.

Three interesting pages on this fascinating couple :

Wikipedia :
http://en.wikipedia.org/wiki/PSR_J0737-3039

More serious stuff :
http://www.atnf.csiro.au/news/press/double_pulsar/

http://www.jb.man.ac.uk/news/double-ag/

[Cham]

The addon is finished (can you confirm ?). Here's a link to the lovers :

http://nho.ohn.free.fr/celestia/Cham/PSRJ0737-3039.zip

Install into you Extras folder, type PSR J0737-3039 AB in Celestia, then go !

Feedback would be appreciated.

[Cham]

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
}


[symaski62]

http://arxiv.org/PS_cache/astro-ph/pdf/0602/0602024.pdf

PSRJ0737-3039.

http://arxiv.org/find/grp_q-bio,grp_cs, ... /0/all/0/1

[Jeam Tag]

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.

Seems it works well for me. So, as his coordonates are more accurate than the animation, we can't see the jets of the two neutron stars in the same time we must zoom in one of them, right? And it seems to me the jets don't touch the star -beginning is obscure (?§a se dit?), but it is maybe my card. Could you provide a picture of what you have on screen? Thanks for the nice addon, Cham.
La collection d'objets ?©tranges s'agrandie!
Jeam

[danielj]

Very nice,but I open the stc both with Wordpad and Notepad and it is not in a recognizable format.I am using Celestia 1.4.1 final.
The addon works perfectly,but I can??t change the stc file...

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
}


[Chuft-Captain]

Um.... doesn't work properly on my system. Jet effects seen in the video just look like green models on my machine...very boring in comparison.
(Cel 1.4.1, Pentium 1.3Gig, shared memory graphics. no OpenGL2.0 ) ... also, the stars are much further apart.
Perhaps it's just viewpoint? Cham could you post a CelURL for the viewpoint in the video?

[Cham]

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.

Yes, the stars are 800 000 km apart and they have a 10 km radius (they are neutron stars). To view both of them at the same time, you'll have to play with your FOV.


danielj,

the STC file is just a text file. You should be able to open it with your text editor. Others can confirm danielj's problem ?

[selden]

Cham and ChuftCaptain,

There seem to be two issues:
1. The textures in the Addon are quite different from what's shown in the video.

If you look in the /textures/medres/folder with thumbnail viewing enabled, puljet1 is a green spiral instead of blue with white streaks and the pulsar surface textures are blue-and-white instead of yellow.

2. [deleted] not a problem: the blue jet2 is the outer beam and just is very, very faint.

Cham,

A separate problem is that the models jet1.3ds and jet2.3ds specify the wrong capitailzation in the filetypes of the names of their textures. This is a problem for Unix and Linux systems. Either the models need to be changed or the names of the textures need to be changed. E.G. from Puljet2.png (current texture name) to Puljet2.PNG (texture name specified in jet2.3ds). Windows and Mac authors often forget about this problem since those O/Ss ignore filename capitalization.

[Cham]

Thanks Selden, I have edited the meshes to remove the PNG capitalisations. I also edited the SSC to make better jets.

About the video, I don't agree with the yellow texture used for the neutron star. Don't forget this video is just an artistic representation of the real thing. Neutron stars are extremelly hot (millions of Kelvin), so they should be white-blue instead of yellow.

I used green jets (instead of blue) as a "symbol" of Synchrotron radiation, which are normally in the radio spectrum. Those jets are actually made of relativistic electrons spiralling in the intense magnetic field, and emitting radio waves. The spirals are a "symbol" of the electrons paths. The obscure gap close to the star is a way to make the jets looking blurry (limitation of Celestia). I reduced that gap to make longer jets.

I'll release a new version later today.

[Cham]

Done !

New version here :

http://nho.ohn.free.fr/celestia/Cham/PSRJ0737-3039.zip

The SSC and STC have been saved as Unicode 8 format. Jets are better.

Need feedback please.

[Jeam Tag]

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

Well, the screenshot by chuft-captain answered my question. All works fine for me, so. Thx. Jeam

[selden]

Cham,

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. I downloaded it with different browsers, so I'm relatively sure I wasn't getting a cached version.

Code: Select all

$ unzip -l PSRJ0737-3039-3.zip | grep 3ds
    92900  01-12-05 16:23   PSR J0737-3039/models/jet1.3ds
    92901  01-12-05 16:22   PSR J0737-3039/models/jet2.3ds


The catalog files were updated:

Code: Select all

$ unzip -l PSRJ0737-3039-3.zip | grep ssc
     3328  08-31-06 12:13   PSR J0737-3039/PSR J0737Jets.ssc
       82  08-31-06 12:13   __MACOSX/PSR J0737-3039/._PSR J0737Jets.ssc


[Cham]

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.

Corrected :

http://nho.ohn.free.fr/celestia/Cham/PSRJ0737-3039.zip

[selden]

Looks good!

[Chuft-Captain]

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.

Hm, I downloaded the vid first. I did wonder how you managed to get those sort of effects in Celestia.

Thanks Cham, nice model, and fun to play with, as follows...

Use the "A" to set your speed to approx. 200 km/sec then click on the URL at this page: http://traitorsclaw.sitesled.com/locations.html

(Unfortunately phpBB has problems with CelURL's containing "spaces" so I've had to put it on a webpage. )

[Cham]

Hmmm, cel links like this one never worked on my system (Mac with Tiger), so your link doesn't work.


By the way, I've noticd an error in the STC code (again!). The star definition for pulsar B has a wrong MeanAnomaly value. I've updated the zip file (link given in the first post of this topic). In the STC file, you should have this code for pulsar B :

Code: Select all

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

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

   RotationPeriod 7.70405763166667E-04
}


In the old version, there was a wrong ArgOfPericenter 0 and the wrong MeanAnomaly 180.

[Chuft-Captain]

As I'm feeling sorry for you Cham (what with you being a MAC owner and all ), here's an image near the start point, you'll have to do it yourself.

[Malenfant]

More a general astrophysics question here, but I don't understand why the pulsars aren't tidelocked to eachother (fully, like Pluto/Charon). I mean, they're massive and very close to eachother, so one would expect them to be tidelocked, which means the rotation axes should be pointing in the same direction on both bodies and the rotation period is the same as the orbital period...

So why isn't that the case here? Is there some weird relativistic/spacetime warping effect preventing this from happening?

[Cham]

Malenfant,

the answer is simple : those pulsars are really massive (a bit more than our sun, each), so it takes time to slow down and synchronise. And they are probably not old enough to be tide locked. They are already spiraling inward and are about to collide in about 85 millions of years.

Also, don't forget their extreme densities (more than a sun weight in a 10km radius object !!!). They are most probably perfectly spherical, so no tide bulges to slow them down. Their quadrupole moment is probably zero !

Pulsars are really fascinating exotic objects.