(cba:news) WX Ari, V1101 Aql, FO Aqr, and the two assassins
jop at astro.columbia.edu
Mon Oct 20 07:22:52 EDT 2014
Great, great coverage on ASASSN-14ei (see Enrique's note in cba-chat).
7 echo outbursts and counting... and some other 15-hour wiggles that
resist understanding (no real precedent for such things). The usual
southern stalwarts: Gordon, Berto, Josch, Bob Rea... and now I see some
Peter Nelson data coming in. Follow this helium CV to the last photon.
And now GAIA, a new arrival to our Solar System, has found another
Actually this is a re-discovery of ASASSN-14cn, announced back in June
2014. But the ATel announcement of the doubled helium lines ratchets
this guy up in importance. Very poorly placed in the evening sky. But
on the other hand, the period is likely to be very short (<1 hour), so
there's "bang for your buck". Let's get acquainted with this guy in
this last month of its season!
Enrique and Richard Sabo have jumped on WX Ari, a VY Scl star
("anti-dwarfnova") now in a low state. As hoped, it has a smooth
orbital modulation now, possibly due to the heated secondary. My
further hope is that we can use this to deduce the temperature of the WD
(and it wouldn't hurt to have a direct measure of that temperature from
HST, by the way). Let's work hard to assemble that orbital light curve.
The period is ~3.5 hours, but it's quite faint, so for high precision
we need to collect many dozens of orbits.
FO Aqr. Wow, CBAers really jumped on this one! The light curves are
beyond beautiful, and demonstrate that the very rapid shortening of the
period really did happen. But the point is proven, and we can now
continue to follow it without intensive coverage. Keep going, but mark
it for occasional (weekly?) observations. At a dec of -8, available to
everyone. Then we'll pick it back up in June 2015.
Finally there's V1101 Aql, the star of 2014 - and no slouch in 2013
either. We suspended our campaign a month ago, and Aquila is slumping
over to the west - BUT it's important that we train our scopes back on
it now. Why? Because, V1101 Aql has the best negative superhumps in
the sky (among CVs; Hercules X-1 and SS 433 are competitors from other
realms). We want to study it from the longest possible yearly baseline,
to assess how good or how bad the superhump clock is in keeping time.
Let's observe it over the next month, then pick it up again in May 2015
- that'll keep the observation gap short.
Other campaigns: status quo ante. I'll write again in a coupla days.
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