Talk:AR Scorpii

Not a Delta Scuti type variable

The star is clearly not a Delta Scuti variable, although I went to SIMBAD and verified that it is indicated as such in their database. Delta Scuti variables are A0-F5 giant to main sequence stars. This system is clearly an M dwarf + White Dwarf binary. The Marsh et al. 2016 Nature paper reference at the bottom indicates this misidentification.

Having looked at a couple of other papers and preprints it appears that this variable star has not been truly classified yet.

Is there a precedent for this? Should I (or other) change the variable type blank? It obviously also would still have the confusion as the older catalogues have not been updated. Autkm (talk) 18:47, 3 January 2017 (UTC)

Let's leave it blank for now. This is a WD pulsar, the first to be discovered. The Delta Scuti classification is clearly wrong, but I'm not aware of any existing type of variable star which fully accomodates AR Sco and its extraordinary variability. At some point in the reasonably near future, a new class of variable will be recognized by the astronomical community. Astro4686 (talk) 05:39, 5 January 2017 (UTC)

Separation and orbital stability

Orbital period under 4 hours? Wow. What is their separation, and how long will it be until they spiral into each other? Fig (talk) 22:41, 26 October 2017 (UTC)

3.5 hours is not exceptionally short for a binary orbit. See AM Canum Venaticorum for example, at 17 minutes. The size of the orbit is not much larger than the sun, but there is no imminent expectation of a merger. The nature of the interactions between the two components is not fully understood, but it is thought likely that repeated periods of spin-up and spin-down have taken place over tens of millions of years, and this is expected to continue. Lithopsian (talk) 20:54, 30 October 2017 (UTC)