Pulsars PSR J0737-3039 A and B binary !

[Cham]

Here are some interesting articles on this unique pulsar binary :

http://skytonight.com/news/3308446.html?page=1&c=y

http://skytonight.com/news/3310106.html?page=1&c=y

[Cham]

Guys, I've just updated the files for more accurate data on pulsars orbit and to add the ability to show the orbits themselves. Much nicer and more interesting this way. Also, I strongly suggest that you add this line of code to your start.cel file, to show the system barycenter :

Code: Select all

# Mark the barycenter of a pulsar binary :
mark { object "PSR J0737-3039 AB" size 12 color [ 0 0.5 1] symbol "plus" }

See pictures below :



Same download link as before :

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

Feedback would be appreciated.

[Chuft-Captain]

Cham,

If these latest changes only require changes to data files and not modelingl changes, would you mind packaging them as a separate (ie, 5-10KB) download?
There's no point downloading the model (which is the largest part) if we've already got it.

[Malenfant]

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.

Hm, you're right... I just tried running this through my solar tide calculator (which works fine for planets) and it seems that it would take about 1e13 to 1e14 years for the companion to become tidelocked to the primary. I've assumed a tidal dissipation factor (Q) of 1, which is very low - if you increase that then it takes even longer. I also assumed a rotation period of 1 millisecond and a radius of 10 km.

The escape velocity of the companion is crazy though - 182,156 km/s!

[Cham]

The escape velocity of the companion is crazy though - 182,156 km/s!

Those guys are in an ultrarelativistic regime. Their ArgOfPericenter value is actually changing in time with a rate (the Advance of periastron) measured to be 16.89947 deg/yr, which is pretty high ! General relativity is Queen, here !

This is why I think Chris should update Celestia to include orbit precession (advance of periastron) and to let us choose the precession axis. It's a must, about pulsars, black holes and other cute things ...

[Malenfant]

I just downloaded it and fired it up - looks great, Cham! I really like the texture on the pulsars too.

Check the bugs board too though, I noticed something weird when I slowed it down to 1000x - I know it locks up then, but didn't realise that loading a webpage in another window makes it move again!!

[Cham]

Check the bugs board too though, I noticed something weird when I slowed it down to 1000x - I know it locks up then

I also noticed this small bug in various situations. It's not related to my addon. Appears to be general in Celestia.

About the pulsars, I'll try to add some magnetic field lines in pure CMOD format, a bit like some of Selden's graticules. Something like this :

[Malenfant]

Check the bugs board too though, I noticed something weird when I slowed it down to 1000x - I know it locks up then

I also noticed this small bug in various situations. It's not related to my addon. Appears to be general in Celestia.

I know that, I remember when it was first spotted. But what I didn't realise was that doing stuff outside Celestia actually got it moving again!

[Cham]

Here's a TEST version of my magnetic field lines. But I don't want a mesh. I want Selden's trick to draw lines with the CMOD format. I don't know how to do that !

[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

update 08/24/2006
http://arxiv.org/PS_cache/astro-ph/pdf/0602/0602024.pdf



http://simbad.u-strasbg.fr/sim-id.pl?pr ... ch3=2000.0

Code: Select all

Barycenter "PSR J0737-3039 AB"
{
   RA   114.46353
   Dec   -30.66132
   Distance 1956.93863   # (600 pc) 
}

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   ?? # Orbital semi-major axis (R?°) 1.26
                Eccentricity   0.0878
                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   ?? #  Orbital semi-major axis (R?°) 1.26
                Eccentricity   0.0878
                Inclination   0
                AscendingNode   0
                ArgOfPericenter   0
                MeanAnomaly   180
        }

   RotationPeriod 7.70405763166667E-04  # 2.8 sec
}

[Cham]

Thanks symaski62, but I already have very precise data about this system, from a private communication with one of the discoverers. This astronomer is in the process of publishing his article in "Science". I'm already in the process of updating the addon with more precise values than from your article. I'm also in the process of building a nice magnetic field lines representation for the pulsars (I have lots of maths to do).

[Cham]

MAGNETIC FIELD LINES !







This is a pure dipole field. You should see that live in Celestia, precessing with the jets. I'm not yet sure about the color choice and the transparency. I can change that very easily. Any opinion on color and transparent effect for those lines ?

Also, what about the lines density ? Is this better with less lines ?


By the way, I now have a nice trick to deform those field lines and make them for ... Earth, Io, Jupiter, etc ... considering solar wind !!

[Malenfant]

that definitely looks cool

[Cham]

Okay, I need your opinion. Here's a link to the actual version. It's not finished, as I need to decide about the field size, color and transparency. Without enough field lines, we don't see the magnetic field features. If there's too much field lines, the model becomes messy and confused. So the addon needs some adjustements. Please, could you test this version and tell what you think about FOUR things (please, be specific) :

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

1- Field size. Is it too big relative to the central star and its jets ? If yes, try by removing the file "Magnetic-Field2.ssc". Is it then too small, relative to the jets ?

2- Field density : Is the field too dense (too much field lines) ? I don't want this thing to be messy.

3- Color : What about the field color (kind of yellow) ? I've tried blue, green and some other variations, and I'm not decided, yet.

4- Transparency : Are the field lines too "strong" or too apparent ? Should they be darker (more transparent) ?


Please, I need feedback ...

[ANDREA]

Okay, I need your opinion. ........Please, I need feedback ...[/

Hello Cham, here are mine:

1- Field size:
Aesthetically it looks the right size, but obviously I have no idea of how big it should really be (even if I suppose it should be wayyyy bigger, IMHO);
2- Field density:
the medium one is OK for me, not less, no more;
3- Color:
I was used to the old pulsar green color, but this looks more realistic, so it has my vote;
4- Transparency :
IMO they should be darker (more transparent).

I wish to add another suggestion: the inner jets are very bright, I think they should be dimmer, like the outer ones, or just a little brighter.
IMHO, obviously, but this is only an aesthetic opinion.
Well done, I'll put it in my "The Universe" script, as final release will be available.
Bye

Andrea

[buggs_moran]

1- Field size. Is it too big relative to the central star and its jets ?
Not if that is the full range of the field's influence...
If yes, try by removing the file "Magnetic-Field2.ssc". Is it then too small, relative to the jets ?
I did, and I think I actually do like it more without file 2

2- Field density : Is the field too dense (too much field lines) ? I don't want this thing to be messy.
I would probably halve it. Unless perhaps you can blur the lines? Or maybe more transparent

3- Color : What about the field color (kind of yellow) ? I've tried blue, green and some other variations, and I'm not decided, yet.
Blue would be my personal selection

4- Transparency : Are the field lines too "strong" or too apparent ? Should they be darker (more transparent) ?
I think I would want the "hint" of a field so I would make them more transparent as well...


Are these going to be open for use? I would love to possibly use them in my cataclysmic binaries (btw, finished my importer, now I am compiling data...)

[Cham]

My pulsars addon is finished. Same link as above. If there's enough interest, I'll upload it to the Motherlode.

I reduced a bit the opacity of the magnetic field lines, and removed some lines.

[danielj]

Something is wrong.I have 4 JETS in the pulsar.
Any idea what could be wrong?
I have 3 ssc and 2 stc files in PSR J0737-3039 folder inside Celestia>Extras
The files are PSR J0737.stc,PSR J0737 Jets.ssc,PSR J0737-Jets.ssc,PSR J1210.stc and PSR J1210-Jets.ssc.

My pulsars addon is finished. Same link as above. If there's enough interest, I'll upload it to the Motherlode.

I reduced a bit the opacity of the magnetic field lines, and removed some lines.

[buggs_moran]

Something is wrong.I have 4 JETS in the pulsar.
Any idea what could be wrong?
I have 3 ssc and 2 stc files in PSR J0737-3039 folder inside Celestia>Extras
The files are PSR J0737.stc,PSR J0737 Jets.ssc,PSR J0737-Jets.ssc,PSR J1210.stc and PSR J1210-Jets.ssc.

Assuming you have the latest version, delete PSR J0737-Jets.ssc. I usually delete the whole folder before replacing an addon. That way if the developer changed a file name (which I do a lot of) nothing gets screwed up.

[Cham]

I think you simply copied the files over the old one. Just copy the complete folder over the old one, not the files. The files and folders you should get after unzipping are these , and nothing more:

Documentation (folder)
Field-lines (folder)
models (folder)
PSR J0737-Jets.ssc
PSR J0737.stc
PSR J1210-Jets.ssc
PSR J1210.stc
Readme.txt
textures (folder)