CrazyNeutrino said:
There’s a super weird reason this star flashes every 2 minutes
Astronomers think they might have finally solved a stellar mystery that’s been puzzling scientists for more than 40 years – why a strange star called AR Scorpii flashes brightly and fades every 2 minutes.
New observations show that the star system isn’t just something we’ve never seen before, it’s something astronomers have never even imagined could be possible before, and it serves as a reminder that we still know so very little about the phenomena within our Universe.
more…
The video aint great. It doesn’t show the orbit and the white dwarf is wrongly portrayed as a neutron star.
> Using a range of telescopes, including Hubble and the Very Large Telescope, the amateur astronomers
Since when have “amatuer“s used both Hubble and the VLT?
> AR Scorpii is actually not one, but two stars. And they’re locked together in an incredibly violent dance, orbiting each other once every 3.6 hours. The duo is made up of a compact white dwarf the size of Earth but 200,000 times more massive, and a cool red dwarf which is one-third the size of our Sun. The regular flashing arises because the white dwarf spins so fast that it energises electrons up to almost the speed of light, creating a cosmic whip that lashes its red dwarf partner, triggering the release of a huge pulse of electromagnetic radiation every 1.97 minutes – hence the flashing.
That’s very peculiar.
From scientific paper:
“AR Sco’s brightness varies on a 3.56 h period; it was this that caused the δ-Scuti classification. The scatter visible in Fig. 1a prompted us to take optical photometry with the high speed camera ULTRACAM. These data and follow-up observations taken in the ultraviolet and near-infrared all show strong double-humped pulsations on a fundamental period of 1.97 min; the scatter in Fig.1a is the result of the pulsations. Most unusually of all, an hour-long observation at radio frequencies with the Australia Telescope Compact Array (ATCA) also shows the pulsations. The pulse fraction, exceeds 95 % in the far ultraviolet, and is still 10 % at 9 GHz in the radio. Only in X-rays did we not detect pulses. AR Sco’s optical magnitude varies from 16.9 at its faintest to 13.6 at its peak, a factor of 20 in flux.”
More on Delta Scuti stars:
“The delta Scuti stars reside near the point where the instability strip crosses the main sequence in the HR diagram. Stars in a variety of evolutionary states – including pre-main sequence stars – can lie within the instability strip, so long as they have spectral types between F8 and A2. This corresponds to masses between about 1.5 and 2.5 solar masses. They are all short period stars, with individual periods lying in the range of 0.7 to 7 hours.”