1. catdynamics
  2. CU Virginis

CU Virginis

By catdynamics on May 22, 2007.

There is a most curious paper out on CU Virginis

i-6db23991e70a6d526608b12716337127-CUVir2.jpg

CU Virginis is a magnetic chemically peculiar star about 250 light years away.

By peculiar, we mean it has significant overabundance of some elements (factors of ten or more), and the surface composition is visibly inhomogenous and variable.

It is rotating rapidly, period of just over half-a-day, and the rotation axis is approximately orthogonal to our line of sight, while the magnetic field is dipolar, off-center, and approximately orthogonal to the rotation axis.

There is strong radio emission from the stellar magnetosphere, and as it rotates, the radio beam sweeps across our line of sight, much like a lighthouse beam.

The radiation has a narrow beamed component - half hour width beams, which are 100% right hand circularly polarized.

The paper also claims, based on a small number of observations over a short baseline, that the star is spinning down very rapidly, presumably through magnetic braking. The star has previously been observed to abruptly increase its rotational period.

Weird shit.

The authors suggest the star is undergoing rapid spin-down at it heads down to the settle on to the main-sequence, and that the radio emission is an interesting model for coherent radio emission in pulsars.
Interesting, though I am skeptical as to how far the latter analogy will stretch.

Tags
astro

More like this

Plagiarism, Garbling, and Superluminal Motion
I no longer recall who pointed me to this current.com post titled "Scientists Make Radio Waves Travel Faster Than Light "-- somebody on Facebook, I think. As it would be a pretty neat trick to make light move faster than light, I took a look. The opening is fairly standard semi-gibberish: Scientist…
Stars tip over, Relativity left standing
For over 20 years, the binary star DI Herculis has been measured to have anomalous precession, inconsistent with the predictions of general relativity, in the limit of two spherical masses orbiting with the measured orbital parameters. So, either there were some other classical torques in the…
Electron Spin for Toddlers
The subject of the "spin" of the electron comes up again and again, so as pointed out in a comment, I really ought to do a post explaining what it is and how it works. As a bonus, this gives me the opportunity to do the dorkiest thing anyone has ever done with a cute-toddler video, namely this one…
Why does your galaxy spin?
"Sometimes I don't want to see the puppeteers, sometimes I just want to see the magic therein, and sometimes I just want to pry open the atoms and know why they spin." -Glen Sutton But it isn't just the atoms -- the minuscule building blocks of matter -- that spin. It's also the individual galaxies…

Fascinating that it behaves like a pulsar. Last month it was discovered that brown dwarf TVLM 513 also behaves like a pulsar. Could these discoveries be related?

in this particular star, silicon, chromium, iron and helium, for sure

for the class in general, everything up to mercury, including spectacular overabundances of rare earth elements (by factors of million or more in some cases)

but for CU Vir I don't happen to know if those are measured to be peculiar and a very quick search did not reveal measured abundances
its somewhere, buried under its HD number or somesuch