A New Pulsar Planet?

View previous topic View next topic Go down

A New Pulsar Planet?

Post by Edasich on 15th August 2011, 4:48 am

Dates back October 2010. A possible gas giant revolving the neutron star PSR J1719-14. We eager wait for a publication paper!

http://adsabs.harvard.edu/abs/2010xmm..prop..203P

A binary msp with a planetary mass companion has been recently discovered. For a psr mass of 1.4Msun, we infer a companion mass of 1.3 Jovian masses, which is ten times smaller than that of any other known stellar companion to a msp. This psr is likely the first long-sought example of a msp which descended from an Ultra Compact Accreting X-ray MSP. In the context of a multi-wavelength campaign, we request a 25 ks exposure (sampling 3 orbits of the system) with the aims of:i) identifying the X-ray counterpart;ii) comparing X-ray fluxes and spectra with those of other binaries with other kinds of companions and/or have undergone other evolutionary paths;iii) searching for orbital variations in the X-ray flux, in order to investigate if the new binary can be the progenitor of an isolated msp.
avatar
Edasich
dM star
dM star

Number of posts : 1529
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Lazarus on 15th August 2011, 12:05 pm

Question would be whether this is a bona-fide planet or a remnant of a tidally-disrupted star...
avatar
Lazarus
dG star
dG star

Number of posts : 2873
Registration date : 2008-06-12

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Edasich on 15th August 2011, 12:10 pm

Lazarus wrote:Question would be whether this is a bona-fide planet or a remnant of a tidally-disrupted star...

So undermassive? Another question is the orbital period. If very short (P<<0.1 days), the He-WD option would be likely.
avatar
Edasich
dM star
dM star

Number of posts : 1529
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Lazarus on 15th August 2011, 12:18 pm

Edasich wrote:So undermassive?
Don't see why not. If companion stars get completely destroyed (as suggested by the existence of single MSPs), then presumably there is a stage at which they will have very low masses...
avatar
Lazarus
dG star
dG star

Number of posts : 2873
Registration date : 2008-06-12

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Lazarus on 25th August 2011, 3:51 pm

Well this is a weird one, apparently it is a Jupiter-mass diamond "planet" orbiting the millisecond pulsar PSR J1719−1438.

From the abstract: "its minimum density of 23 g cm−3 suggests that it may be an ultra-low-mass carbon white dwarf."

News release
More discussion at Dynamics of Cats
avatar
Lazarus
dG star
dG star

Number of posts : 2873
Registration date : 2008-06-12

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Edasich on 26th August 2011, 3:37 am

Well, quite an exotic second generation planet, if we want to consider it as "planet"
avatar
Edasich
dM star
dM star

Number of posts : 1529
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by tommi59 on 26th August 2011, 4:18 am

600000km away from pulsar quite nice place Very Happy
avatar
tommi59
Jovian
Jovian

Number of posts : 549
Age : 39
Location : Baile Atha Cliath
Registration date : 2010-07-31

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Edasich on 26th August 2011, 5:05 am

tommi59 wrote:600000km away from pulsar quite nice place Very Happy

Roughly 0.0043 AUs away, nearly twice the Earth-Moon separation. Just figure out the irradiation... affraid
avatar
Edasich
dM star
dM star

Number of posts : 1529
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Mongo on 26th August 2011, 1:19 pm

I wonder how far from spherical this object is. The tidal forces from the (very) nearby pulsar must be enormous. On the other hand, with a density of at least 23 g cm^-3 and a mass equal to that of Jupiter, the surface gravity must be immense as well.
avatar
Mongo
Asteroid
Asteroid

Number of posts : 58
Age : 55
Location : Greater Toronto, Canada
Registration date : 2009-05-18

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Lazarus on 28th August 2011, 4:10 pm

So on looking at this further, the "diamond" idea doesn't seem to work particularly well.

The most common type of white dwarf is a carbon-oxygen white dwarf, in which the core of the white dwarf is made up of carbon and oxygen. This is then usually (but not always) surrounded by layers of hydrogen and helium.

Oxygen is heavier than carbon and apparently crystallises at higher temperatures, therefore the inner part of the core is very oxygen-rich, with carbon-rich material further out. This applies even to the diamond star BPM 37093 that was announced in 2004: the best-fitting model is for an oxygen core.

So if this object is indeed the core of a white dwarf star, we should probably expect there to be a lot of oxygen in there...
avatar
Lazarus
dG star
dG star

Number of posts : 2873
Registration date : 2008-06-12

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Sirius_Alpha on 28th August 2011, 8:17 pm

Transformation of a Star into a Planet in a Millisecond Pulsar Binary
http://arxiv.org/abs/1108.5201

Millisecond pulsars are thought to be neutron stars that have been spun-up by accretion of matter from a binary companion. Although most are in binary systems, some 30% are solitary, and their origin is therefore mysterious. PSR J1719-1438, a 5.7 ms pulsar, was detected in a recent survey with the Parkes 64m radio telescope. We show that it is in a binary system with an orbital period of 2.2 h. Its companion's mass is near that of Jupiter, but its minimum density of 23 g cm$^{-3}$ suggests that it may be an ultra-low mass carbon white dwarf. This system may thus have once been an Ultra Compact Low-Mass X-ray Binary, where the companion narrowly avoided complete destruction.

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3515
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: A New Pulsar Planet?

Post by Edasich on 31st August 2011, 2:33 pm

avatar
Edasich
dM star
dM star

Number of posts : 1529
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Lazarus on 15th March 2012, 4:49 am

Formation of the planet around the millisecond pulsar J1719-1438

Still think it's better to call the companion a white dwarf rather than a planet.
avatar
Lazarus
dG star
dG star

Number of posts : 2873
Registration date : 2008-06-12

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Edasich on 26th October 2015, 10:49 am

As I foresaw some low-mass substellar companions to neutron stars have been listed in EPE...

http://exoplanet.eu/catalog/psr_j1807-2459_b/
http://exoplanet.eu/catalog/psr_b1957%2B20_b/
http://exoplanet.eu/catalog/psr_j2051-0827_b/
http://exoplanet.eu/catalog/psr_j2241-5236_b/

...along with the K2 white dwarf with transiting planetesimal...

http://exoplanet.eu/catalog/wd_1145%2B017_b/
avatar
Edasich
dM star
dM star

Number of posts : 1529
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Sirius_Alpha on 26th October 2015, 8:20 pm

I can understand the pulsar companions based on precedent, but the WD asteroid? Really?

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3515
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: A New Pulsar Planet?

Post by Stalker on 27th October 2015, 4:14 am

Why not?

_________________
avatar
Stalker
Jovian
Jovian

Number of posts : 530
Age : 26
Location : Paris, France
Registration date : 2008-06-16

View user profile http://exoplanetes.wetpaint.com/

Back to top Go down

Re: A New Pulsar Planet?

Post by Edasich on 27th October 2015, 4:45 am

If so I have more pulsar and WDs with very low-mass companions even at longer orbital periods (>1-2 days).
avatar
Edasich
dM star
dM star

Number of posts : 1529
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Stalker on 27th October 2015, 5:19 am

Me too. A lot of cataclysmic variables have substellar secondaries.

_________________
avatar
Stalker
Jovian
Jovian

Number of posts : 530
Age : 26
Location : Paris, France
Registration date : 2008-06-16

View user profile http://exoplanetes.wetpaint.com/

Back to top Go down

Re: A New Pulsar Planet?

Post by Edasich on 29th October 2016, 4:07 am

Thread bump for recent addition to EPE: PSR J0636+5129 b

Original paper:

Ordinary X-rays from Three Extraordinary Millisecond Pulsars: XMM-Newton Observations of PSRs J0337+1715, J0636+5129, and J0645+5158

We present the first X-ray observations of three recently discovered millisecond pulsars (MSPs) with interesting characteristics: PSR J0337+1715, PSR J0636+5129, and PSR J0645+5158. PSR J0337+1715 is a fast-spinning, bright, and so-far unique MSP in a hierarchical triple system with two white dwarf (WD) companions. PSR J0636+5129 is a MSP in a very tight 96-min orbit with a low-mass, 8 MJ companion. PSR J0645+5158 is a nearby, isolated MSP with a very small duty cycle (1-2%), which has led to its inclusion in high-precision pulsar timing programs. Using data from XMM-Newton, we have analyzed X-ray spectroscopy for these three objects, as well as optical/ultraviolet photometry for PSR J0337+1715. The X-ray data for each are largely consistent with expectations for most MSPs with regards to the ratios of thermal and non-thermal emission. We discuss the implications of these data on the pulsar population, and prospects for future observations of these pulsars.

... and it was amongst unconfirmed substellar companions recently reported by me. Surprised
avatar
Edasich
dM star
dM star

Number of posts : 1529
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: A New Pulsar Planet?

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum