Skip to main content

Landmark paper on CV evolution from Joe Patterson and CBAers

3 posts / 0 new
Last post
SXN's picture
Landmark paper on CV evolution from Joe Patterson and CBAers

The paper describes: "One: why the ER UMa class even exists (because all members can be remnants of recent novae). Two: why ER UMa stars and short-period novalikes are rare (because their lifetimes, which are essentially cooling times, are short). Three: why short-period novae all decline to luminosity states far above their true quiescence (because they're just getting started in their postnova cooling). Four: why the orbital periods, accretion rates, and white- dwarf temperatures of short-period CVs are somewhat too large to arise purely from the effects of gravitational radiation (because the unexpectedly long interval of enhanced postnova brightness boosts the mean mass-transfer rate). And maybe even five: why very old, post-period-bounce CVs are hard to find (because the higher mass-loss rates have “burned them out”). These are substantial rewards in return for one investment of hypothesis: that the second parameter in CV evolution, besides Porb, is time since the last classical-nova eruption."

What makes this paper even

What makes this paper even more remarkable is that "essentially all" of the 20 years of data used in this paper comes from CBA (that is amateur) telescopes.  Further, most of the data is unfiltered.  This should be required reading for  people who go on frequent rants over unfiltered data.

The paper does a good job of describing the CBA Network and how unfiltered data from different telescopes is spliced together to form a nightly light curve and eventually a paper.

An interesting read.

Matthew Templeton
Interesting paper

This is a good paper -- very good work on the part of the CBA group.  Also a good example of why even historically well-observed objects are worth monitoring for changes, which is what BK Lyn did with no warning.

Regarding unfiltered observations, this is a good example of a project where unfiltered photometry is appropriate -- blue objects where the colors do not change dramatically and where rapid time-series is required.  I don't think the push (not rant) to encourage filtered observations of objects that require it is disproven by this work -- Joe Patterson and CBA were observing disks in YSOs instead of CVs, he might be saying the same things we do about filters.

Log in to post comments
AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484