4 ms·

If it's periodic, it's something orbiting something. If it's powerful enough to be seen 500 million ly away, one of the two orbiting objects is going to be a b

If it's periodic, it's something orbiting something. If it's powerful enough to be seen 500 million ly away, one of the two orbiting objects is going to be a black hole.

CuriouslyC 6y ago
Maybe, but perhaps not in the way you think. A source that emits radiation only at certain angles (think a stellar disco ball) would only "flash" us infrequently as we moved relative to it.
BurningFrog 6y ago
Or one thing rotating. You can imagine other cyclical processes, but I don't know any are realistic.
- DFHippie 6y ago
  The thing to explain then, in either the precession or the orbiting case, is the variability in the period.
- pas 6y ago
  Variable stars, something involving a cyclic phase transition (from silent to active and back). Something like the Type Ia supernova, where the dense white dwarf siphons off mass from its companion until it reaches the Chandrasekhar limit and bang.
jrichardshaw 6y ago
There's a few ways to do it (and the press release is surprisingly good and mentions most of them), but certainly one of the more obvious explanations is that the emitting object, is in a binary system with some other object, and that modulates the emission mechanism somehow. I don't think either needs to be a black hole though. What I consider the most plausible candidate for emission is probably magnetars (i.e. neutron stars with extremely strong magnetic fields), and there's no reason the companion would need to be a black hole either, you just need a companion that gives a 16 day orbit and that's very easy to do with another star or neutron star.
- DrBazza 6y ago
  Interesting. This galactic magnetar (https://en.wikipedia.org/wiki/SGR_1806%E2%88%9220 https://en.wikipedia.org/wiki/SGR_1806%E2%88%9220) affected the Earth's atmosphere. Just how luminous can an extra-galactic one be? Is the FRB an axial emission?

If it's periodic, it's something orbiting something. If it's powerful enough to be seen 500 million ly away, one of the two orbiting objects is going to be a black hole.

CuriouslyC 6y ago

Maybe, but perhaps not in the way you think. A source that emits radiation only at certain angles (think a stellar disco ball) would only "flash" us infrequently as we moved relative to it.

BurningFrog 6y ago

Or one thing rotating. You can imagine other cyclical processes, but I don't know any are realistic.

DFHippie 6y ago
The thing to explain then, in either the precession or the orbiting case, is the variability in the period.
pas 6y ago
Variable stars, something involving a cyclic phase transition (from silent to active and back). Something like the Type Ia supernova, where the dense white dwarf siphons off mass from its companion until it reaches the Chandrasekhar limit and bang.

jrichardshaw 6y ago

There's a few ways to do it (and the press release is surprisingly good and mentions most of them), but certainly one of the more obvious explanations is that the emitting object, is in a binary system with some other object, and that modulates the emission mechanism somehow. I don't think either needs to be a black hole though. What I consider the most plausible candidate for emission is probably magnetars (i.e. neutron stars with extremely strong magnetic fields), and there's no reason the companion would need to be a black hole either, you just need a companion that gives a 16 day orbit and that's very easy to do with another star or neutron star.

DrBazza 6y ago
Interesting. This galactic magnetar (https://en.wikipedia.org/wiki/SGR_1806%E2%88%9220 https://en.wikipedia.org/wiki/SGR_1806%E2%88%9220) affected the Earth's atmosphere. Just how luminous can an extra-galactic one be? Is the FRB an axial emission?