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Hard X-Ray emmision from Pegasus-II
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Q.
User ID: 45144
12/17/2005 4:19 AM
Report abusive post | Hard X-Ray emmision from Pegasus-II
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The BAT trigger (172969) reported in GCN 4357 (Holland et al)
is definitely not due to a GRB. It is due to a hard x-ray emission
from the RS CVn star II Peg.
Using the full data set from recent Malindi downlinks covering
T-300 sec to T+300 sec, we see a remarkably smooth lightcurve
from this source. The emission slowly increases from 0.02 cnt/cm2-sec
to 0.04 cnt/cm2-sec over the 10 minute interval.
The refined BAT location is RA,Dec = 358.799,+28.620 +/- 2.5 arcmin
{23h 55m 11.6s,28d 37' 11.6"} (J2000). This is 1.7 arcmin from the
catalog position of II Peg.
Using a simple power law, the index is 2.98 +/- 0.42. |
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Anonymous Coward
User ID: 33732
12/17/2005 5:01 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
Hey Q, do you have any info or links on this cataclysmic variable? I can't seem to pull up anything on it. The Dec & Ra doesn't match any of the listings in Peg.
Thanks |
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Anonymous Coward
User ID: 33732
12/17/2005 5:27 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
Ok, nevermind. I found out CV in this case refers to "Canum Venaticorum" variables. Now I gotta figure out what the hell that means!  |
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neti
User ID: 46925
12/17/2005 6:01 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
Here is a graph of the Electromagnetic Spectrum. [link to www.electro-optical.com] from this page [link to www.electro-optical.com]
Hard X-Rays seem to be close to the Gamma Ray range.
 What's the significance between this and a gamma ray burst, except in the length of it maybe, ie. 10 minutes (?) |
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Anonymous Coward
User ID: 45144 (OP)
12/17/2005 6:14 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
Canum Venaticorum
I think its another binary system
I used to have this one loaded on my previous celestia setup :(, must get that all back up they it used to be.
==
[link to www.theculture.org] |
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Q
User ID: 45144 (OP)
12/17/2005 6:27 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
What's the significance between this and a gamma ray burst, except in the length of it maybe, ie. 10 minutes
===
Good question, at a guess (and I may be wrong) is that it is not associted to a black hole, supernove, dieing star or anything of this nature as the spectrum emmited is just under that of a gamma burst.
So perhaps it is a cataclysmic X-Ray emmision from Alpha or Beta -CV as the genius on post 2 pointed out. |
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Q
User ID: 45144 (OP)
12/17/2005 6:29 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
FYI last year there was a 9 Minute GRB so time of emission is insignificant as far as the diff between X-ray and Gamma goes. |
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Anonymous Coward
User ID: 45144 (OP)
12/17/2005 6:34 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
is peg the one with the star that has an increadibly fast spin rate with a photon emmiting star in the system? |
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neti
User ID: 46925
12/17/2005 6:43 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
AC 33732,
Here's something on "Canum Venaticorum" [link to math.ucr.edu] Apparently these stars are white [lol, like ours is getting to be] with strong magnetic fields and an abundance of heavy metals in them.
RS as in RS CVn means "Reference System", see this link [link to www.astro.yale.edu] It's in powerpoint (ppt) which I can't open on a Mac, but the info should be in there.
Q., could you tell me what your last line in the op means? I simply don't know. |
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Anonymous Coward
User ID: 45144 (OP)
12/17/2005 6:50 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
Funny thing is; Beta Canum Venaticorum is classified as a yellow dwarf.
Ill get some info to see if I am right about peg and put it here so you can understand neti. |
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Q
User ID: 45144 (OP)
12/17/2005 6:52 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
I am mistaken, it sis 51 peg;
have a read - its a remarkable system that defies previous models.
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[link to zebu.uoregon.edu]
51 PEGASI
N. Houk, University of Michigan, has determined a spectral type of G2-3 V for 51 Peg from a 1-min IIa-O 10-deg objective-prism plate taken on 1981 Aug. 6 with the Burrell Schmidt telescope at Kitt Peak. The high-quality spectrum (resolution about 0.1 nm; dispersion 10.8 nm/mm, i.e., normal classification dispersion), together with the use of several standard spectra, revealed no duplicity or chemical peculiarities. The spectrum is definitely not as luminous as IV (quoted in the 1982 Bright Star Catalogue from Keenan and Pitts 1980, Ap.J. Suppl. 42, 561), or even 'IV-V'. It is also earlier than the temperature type of G5 given in several older publications.
Confirmation of Velocity Variations of 51 Peg
Geoff Marcy & Paul Butler
U.C. Berkeley
San Francisco State Univ.
On Oct. 6, Michel Mayor and Didier Queloz at Geneva Observatory announced that 51 Pegasus has a planet orbiting it. If confirmed, this would be the first detected planetary system around a normal star. 51 Peg is a Solar-Like star, 40 light years away.
We have obtained 27 independent spectra of 51 Peg using the 3-meter telescope at Lick Observatory. The observations span 4 days. The goal was to detect the wobble of 51 Peg in response to the gravitational pull of the supposed planet. Velocities of stars are derived from the Doppler effect, as a part of our long-term search for planetary systems. Our Doppler technique yields a velocity precision of 3 m/s --- human walking speed.
We find that the velocities of 51 Peg during 4 nights are sinusoidal, with an amplitude of 106 m/s, peak to peak (53 m/s semiamplitude). The RMS residual (scatter) is 2.5 m/s from the sine wave, consistent with our errors. We find a period of 4.2 days which is presumably the orbital period of the unseen companion as it gravitationally pulls its host star around in a circle.
We therefore confirm the sinusoidal velocity variations reported by Michel Mayor and Didier Queloz of Geneva Observatory. The orbital period of 4.2 days is exactly what they reported. Our velocity amplitude of 53 m/s compares favorably with their measured amplitude of 59 m/s, within their errors.
The best, and straightforward, interpretation is that 51 Peg is orbited by an unseen companion having a mass of about 0.5 Jupiter masses, and orbiting the star at a distance of 1/20 the Earth-Sun distance.
The unknown inclination of the orbital plane leaves some uncertainty in the mass of the planet; it could be somewhat larger than 0.5 Jupiter Masses.
Many question remain unanswered. How did a Jupiter-like planet form so close to its host star? Can a planet really survive so close, since its surface temperature would be about 1000 Centigrade? Are there other planets orbiting 51 Peg?
This page contains some corrections to the factual material presented here which have been sent in my informed readers. Thank you:
1. In the temperature scaling arugment, a temperature of 300K was used. This is just an approximation. For instance, the average temperature at 30 degrees latitude is 285K and averaged over the earth this temperature is 276--278 K. This has the effect of lowering the quoted temperature from 1200K to 1100K.
2. For rotating planets, a given latitude zone will heat up but then reradiate that heat over its full circumference. If this planet is tidally locked, as suggested, then this mechanism is in operative and the temperature is appriximately 1/pi (about 30%) higher. Hence the 1100-1200 K range would be 1500-1600 K.
3. The calculation on the solar wind density at 0.05 au is incorrect (believe it or not, I actually knew this at the time) but is okay to an order of magnitude. A better way to state the scaling problem is not in terms of particle density but rather particle flux. This particle flux is given by: |
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neti
User ID: 46925
12/17/2005 7:49 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
From what I can gather from what you've posted, Q., this star Pegasus-II has a pulse period of 4.2 (4.15) days, and they have speculated that there is a planet the size and composition of Jupiter orbiting it at a distance of 0.05 AU, or 1/6th the distance between Mercury and the Sun. This is incredibly close and the scientists are trying to put their laws of physics to it, but it's still a puzzle to them.
The other explanation is in the link I gave [link to math.ucr.edu] and that is that the heavy metals in a strong magnetic field cluster and produce the pulsing behaviour, simulating the revolution of another planet or star when is not really so.
The explanation is this:
"..these variations is just the observed period of rotation of the star itself!
How to explain all this?
Here's what Petit says: "It is thought that the over-abundant metals in the atmosphere are not uniformly distributed but, trapped by the magnetic field, are localized at certain points. This leads to an irregularity in brightness made perceptible by the rotation. Work carried out in recent years has shown that the localization takes the form of rings or segments and not just of irregular patches."
Wow! I wonder what people think, or know, now (Petit's book appeared in French in 1982, and he says there is much research on these stars, so maybe more is known.) Are we supposed to imagine a star with fragmentary rings of vaporized metal around it, held there by magnetic fields? Pretty neat."
So not all is known from a distance, as for instance from Earth, and there is much speculation, put forward perhaps as fact.
I am reminded of the wording in 'Contact from the Pleiades' in which a group of people in Minesota who had been contacted by another group of Pleiadians, 'not Meier", wrote:
"Physics textbooks erroneously declare our sun to be, in effect, a nuclear reactor. It is not. Because the scientific community feels confident that nuclear power is a part of nature they, as a body, have ceased to consider the possibility that perhaps they do not have all of the answers. Due to this arrogance, they are not even looking at nuclear technologies as possible causes of the damage we see occurring to our ionosphere,"
See [link to www.gaiaguys.net] and scroll down to where it starts: "Nuclear energy and PLANET EARTH" and read from there. |
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Q.
User ID: 45144
12/17/2005 7:59 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
So not all is known from a distance, as for instance from Earth
==
I agree without doubt Neti.
Thats a pretty wild picture to imagine.
lumps of metal get magnetised and clump together creating a greater magnetization effect. |
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neti
User ID: 46925
12/17/2005 8:04 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
I really don't know enough about it to comment, except that it seems logical. Magnetism affects metals the most.. |
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Q.
User ID: 45144
12/17/2005 9:13 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
None of us know enough about anything, and always will be the case.
That’s why I like thinking out loud amongst inquiring minds such as yourself and the great many others on GLP.
I am almost bed bound now, fading fast... |
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neti
User ID: 46925
12/17/2005 9:18 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
Cheers, Q., and goodnight. I'm heading soon too. |
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Q.
User ID: 45144
12/17/2005 9:21 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
Sleep well brother and pleasant dreams to the younger one. |
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neti
User ID: 46925
12/17/2005 9:25 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
Thanks, Q. |
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Anonymous Coward
User ID: 12494
12/17/2005 9:32 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
SO, like, does this mean Nancy was right? |
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neti
User ID: 46925
12/17/2005 10:00 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
Right about what? |
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Anonymous Coward
User ID: 12494
12/17/2005 10:03 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
whatever |
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neti
User ID: 46925
12/17/2005 10:10 AM | | Re: Hard X-Ray emmision from Pegasus-II | Quote |
This information does not come from Nancy, but is at the links provided.
If you can be more specific then we can discuss, else not, because I don't know what Nancy writes. |
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