Comments on: New Type of White Dwarf Stars Discovered

By: bob

bob — Sat, 03 May 2008 16:25:50 +0000

As for what causes it, better equipment will reveal more data that we cannot see now. It is likely that the pulsing may be caused by material drawn toward the WD gravitationally while the strong magnetic field interacts with it periodically or funnels it down to the surface which then radiates it outward.

Degenerate matter has the habit of shrinking when more matter is added and there is unlikely any symmetrical infall of matter onto the WD. The shrinking is a change in position of matter in the magetic field and that should induce a pulse. The degenerate electrons cannot be the source of the magnetic field pulses but this does not mean that the nuclei are degenerate. They can shift energy levels and radiate energy.

By: Ricky Diaz

Ricky Diaz — Sat, 03 May 2008 09:18:26 +0000

This discovery took place over a year ago. Interested in pulsating neutron stars or pulsars, I searched "pulsating white dwarfs" at google.com just to check in case it was true, because there, I have good luck sometimes searching for something I didn't know about. Like a pulsar spinning over 1000 times per second, a white dwarf completing a rotation in minutes, a neutron star spinning only once every 12 seconds, a planet around a quadruple star system, or a planet that orbits it's star in less than 2 days, the Sun possibly having a red dwarf star or brown dwarf companion, a new mini-solar system forming around a brown dwarf only 12 times Jupiter's mass, and a mass that might indeed be a red dwarf star although ant most surprising, it's only 17% larger in diameter than Jupiter, while a planet less massive than Jupiter is 70% larger in diameter than Jupiter. I was hoping there would be a gas planet larger than any red dwarf star, because a planet larger than a star, that's amazing. Over a year ago, I saved a motion picture of a pulsating white dwarf brightening and dimming. I still have the image. I love google.com.

By: RUF

RUF — Sat, 03 May 2008 01:25:50 +0000

Would these be DQ class white dwarfs?

By: AJames

AJames — Fri, 02 May 2008 16:19:00 +0000

Those interested might like to read the "Life and Times of an Intermediate Mass Star – in Isolation/in a Binary"; QJRAS, 26, 1, (1985) You can download the article from the ADS;
Although this is a technical article, reader here should easily understand it. Perhaps the best section is Figure 19, which shows the mass of the white dwarf against the initial star mass, and shows the typical composition of the white dwarf as mass increases.-including the Carbon-Oxygen White Dwarfs (CO White Dwarfs) .
Furthermore, this article confuses me, as the three types of white dwarfs, at least there ashes, Helium, Carbon-Oxygen, Oxygen-Neon White Dwarfs.
Also Carbon-Oxygen white dwarfs have been established for ages, though hot ones are rarer. Obviously, stars that pulsate as WD, must lie inside the instability strip on the H-R diagram, which is placed at 12,300K at solar luminosities. These are the ZZ Ceti variables, whose pulsations are in multiple periods or non-radial modes.
Q. What I don't understand is how these pulsations are believed caused – especially if they are away instability strip?

By: kurtisw

kurtisw — Fri, 02 May 2008 14:33:43 +0000

> I wonder if these carbon starts are just pumping out diamonds?

Probably not. These stars don't have any wind that we can measure, and they may have lots of oxygen (which is hard to detect). If matter were being spewed out, the carbon would want to combine with the oxygen and make carbon monoxide. So, if you go near one of these stars, hold your breath.

> If this is a white dwarf, why does it look so blue?

First, "white" was an appropriate color for many of the first white dwarfs discovered, but the name stuck despite some being blue and some yellowish. Some people insist on calling these "degenerate dwarfs" to avoid the misnomer, but that just adds to the confusion.

Second, these carbon atmospheres make the star anomolously blue. Carbon blocks ultraviolet light (which hot stars like this one make in copious amounts), so the light somes out in the nearest transparant part of the spectrum, which is blue visible light.

By: AJames

AJames — Fri, 02 May 2008 09:22:17 +0000

To understand the nature of white dwarfs and something about the nature of their evolution, I would recommend reader look at Icko Iben Jr, 1985 article "The Life and Times of an Intermediate Mass Star – in Isolation/in a Binary"; QJRAS, 26, 1, (1985)
You can download the article from the ADS;
http://adsabs.harvard.edu/abs/1985QJRAS..26….1I

or directly download the article in pdf at;
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1985QJRAS..26….1I&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf

Although this is a technical article, reader here should easily understand it. Perhaps the best section is Figure 19, which shows the mass of the white dwarf against the initial star mass, and shows the typical composition of the white dwarf as mass increases.-including the Carbon-Oxygen White Dwarfs (CO White Dwarfs).

By: Vanamonde

Vanamonde — Fri, 02 May 2008 08:38:36 +0000

If this is a white dwarf, why does it look so blue? About the bluest star I have ever seen.

By: venki

venki — Fri, 02 May 2008 08:32:45 +0000

Posted this link in http://www.surfurls.com

By: Terragen

Terragen — Fri, 02 May 2008 03:21:48 +0000

All over-wrought and under-whelming references aside, this article made me think "like a diamond in the sky" and I wonder if these carbon starts are just pumping out diamonds?
And are there advanced races that harvest star-forged diamonds, not to mention the diamonds supposedly raining down on Neptune!?

These things I wonder…

By: Jozef K

Jozef K — Fri, 02 May 2008 02:52:53 +0000

Best Beatles reference ever

By: Bunnyman

Bunnyman — Fri, 02 May 2008 02:40:21 +0000

Throw in seven of the hydrogen/helium remnants and you've got Carbon White and the Seven Dwarfs.

By: Steve

Steve — Fri, 02 May 2008 02:31:30 +0000

*Shakes head at Lucy joke*

By: Hai

Hai — Fri, 02 May 2008 01:57:41 +0000

Does Oxygen White Dwarf exist?

By: Mav

Mav — Fri, 02 May 2008 00:45:56 +0000

Pete:

+1 for beatles reference
-10 for over-used beatles reference

/hello fark

By: br0g

br0g — Fri, 02 May 2008 00:07:04 +0000

pete: that was terrible.

By: pete

pete — Thu, 01 May 2008 22:09:26 +0000

Interesting. Now, somebody ought to develop an observing program like…Long Undulating Carbon Yield. Then we can have LUCY in the Sky….with Diamonds. pete