[vsnet-chat 7282] Re: [AVSON] Prioritizing CV targets

[Stan Walker]

Hi Mike,

Good to see you on AVSON. Oddly enough I have sent an article to the RASNZ 
VSS which will probably come out in the March Newsletter about some aspects 
of CV observing. I posted something on AAVSO some time ago about the lack of 
value in finding the 500th SU star - back when I began they weren't even 
known! Much can change in 40 years.

I agree with you that observing the other types such as SS Cyg may pay off 
in time. But in these 'get rich quick' days who wants to spend a lot of time 
monitoring stars with no result. I'm still impressed with one of the more 
famous astronomers, maybe Hubble (my apologies to his shade if I've got it 
wrong), who tied up a major telescope for a few years looking at a cluster 
which he though was actually part of the galactic bulge. Since he was 
mistaken, the results weren't much use. But if you don't try, then you don't 
get anywhere!

Regards,
Stan

----- Original Message ----- 
From: "Mike Simonsen" <mikesimonsen at mindspring.com>
To: <cvnet-discussion at yahoogroups.com>; <baavss-alert at yahoogroups.com>; 
<aavso-discussion at mira.aavso.org>; 
<vsnet-chat at ooruri.kusastro.kyoto-u.ac.jp>
Cc: <AVSON at yahoogroups.com>
Sent: Wednesday, March 08, 2006 6:54 PM
Subject: [AVSON] Prioritizing CV targets


> I'm sure I'm not the only one who has come to this point in their
> development as an observer, so I would like to share my feelings and
> questions, and hopefully spark some relevant discussion.
>
> Besides the numerous list servers in the header, I am blind CCing many
> professional astronomers in hopes that they will respond.
>
> When I first began observing CVs to the near exclusion of all other kinds 
> of
> variables there was not a lot known about many, or most, of the CVs we 
> were
> monitoring. Many were newly discovered and even the type was not known for
> sure. Some had never been seen in outburst. A lot has changed in this 
> regard
> in the last few years.
>
> Preferential treatment has obviously been given to UGSU types. Detecting
> superhumps and deriving a period has been the main game in town in this
> regard. In fact, it seems nobody is interested if the long wait for an
> outburst ends up revealing a 'mere UGSS'. Cases in point, the recent
> outburst of CI Gem and the last two outbursts of DK Cas. Once no humping 
> was
> found they were basically ignored.
>
> Question #1- is there no interesting science to be gleaned from UGs or 
> UGSS?
> If not, why are so many papers and investigations done on SS Cyg and U 
> Gem?
>
> Question #2- is the reason superhump recognition and period determination 
> is
> so popular is because it can be done unfiltered? Isn't there more science
> that can be done by placing UBVRI filters on CCDs while investigating CVs?
>
> Question#3- if you insist on working unfiltered, aren't there a bunch of 
> CVs
> with no known period that you could work on in quiescence to determine the
> period?
>
> I just wonder at the usefulness of jumping all over every new ASAS 
> variable
> to see if it is a UGSU or not and then leaving the whole thing at that. 
> Its
> kinda like the current situation with novae. What is to be learned by
> following yet another novae from outburst to quiescence? OK, its a
> nova...big deal.
>
> As an amateur I would appreciate a little direction in this regard. With
> more and more surveys coming online there will be more and more CVs, novae
> and SN discovered, and we need a way to separate the wheat from the chaff.
> Certainly a million new W UMa eclipsers will be uncovered, but who cares?
> Maybe one or three will prove of interest. I think it is the same with CVs
> and novae.
>
> One argument must surely be, "if we don't study each one to a certain 
> extent
> how will we know which ones will prove interesting".
>
> Question #4- isn't there a way to pre-determine the probability somewhat?
> I don't have an answer. Maybe it takes tools, like spectroscopy, beyond 
> our
> means to make that determination.
>
> For visual observers the situation is still much the same as it has been. 
> We
> are the fire spotters. We patiently monitor CVs for years that may or may
> not prove to be of interest, depending on whether they do the superhump
> dance once they go off. But what of the ones we have now alerted the world
> to that have had their 'superhumpness' or not and periods determined.
>
> Question #5- is there a valid scientific reason for continued monitoring?
>
> Maybe the emerging role of visual observers is to continue monitoring the
> stars with the oldest historical light curves. These 'legacy stars' may 
> show
> period changes or surprises in human time scales we are not expecting, and
> it will be the visual observers who catch these changes, not surveys with
> limited life spans or superhump CCD observers who only observe these stars
> for a few hours on a few nights and then move on.
>
> One of the most interesting things any professional has said in a CVnet
> interview was when Joe Patterson said, "The dwarf-nova outburst itself has
> become generally well understood -- in the sense that there's a theory 
> which
> successfully reproduces the observed phenomena.  But it's noteworthy that
> all of that theory was crafted to fit previously known data -- it has 
> never
> actually predicted something not known in advance. So that higher standard
> of scientific worthiness has never been met.  In addition, the theory 
> breaks
> down when applied to dwarf novae in quiescence -- it predicts about a
> thousand times less accretion than is actually observed!  Plenty of 
> thought
> needed there."
>
> Clearly we could all use some help. Isn't there a way we can help each 
> other
> (pro/am) more? When I founded CVnet I was hoping for more professional
> guidance and participation than we ended up getting. I'd have to say that 
> is
> the only disappointment after the first year. There are a few generous and
> gracious pros who have contributed, and we all appreciate their
> contributions. I am doing what I can to expand on this facet of CVnet.
>
> As a visual observer who now has his other foot in the CCD game, I want to
> do the best and most relevant science both visually and with the CCD. I'd
> like to keep monitoring the CVs that are active and fairly bright 
> visually,
> making as many positive observations as possible, as well as the long term
> projects like waiting for PQ And or EG Cnc (or RS Oph for that matter!) to
> go off. I rather regard my CV program much like an ornithologist with a
> 'life list'. There are a number of CVs I just want to SEE before I go. I
> don't care if they are particularly scientifically relevant. Its a hobby 
> for
> me, and I can wait and monitor what ever I want, enjoying the view, the
> solitude and the oneness with the universe I feel when I am out at the
> scope.
>
> On the other hand, I started doing variable star observing because I 
> wanted
> to contribute to science. There are a bunch of us out here with talent,
> enthusiasm, time, money and expertise who want to do good things. Show us
> the way and we will follow. Empower us and we will amaze you.
>
> "Build it and they will come."
> From 'Field of Dreams', the movie.
>
>
> Mike Simonsen
>
> *********************************
> C. E. Scovil Observatory
> http://home.mindspring.com/~mikesimonsen/
> AAVSO Chart Team
> charts at aavso.org
> CVnet Administrator
> http://cvnet.aavso.org
>
> **********************************
>
>
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