Affiliation
American Association of Variable Star Observers (AAVSO)
Fri, 05/31/2013 - 01:53
Hi All
The RCB star RS Tel may be starting a possible fade judging by my recent observations below:
Apr 1.829 UT: 10.0
May 20.863 UT: 10.1
May 23.841 UT: 10.6
May 30.579 UT: 10.8
Looking at the AAVSO AID, it does show that this star has semi-regular 'dips' down to just above 11th mag every 350 days or so (at least since the last big decline back in 2006). So it's hard to tell whether this is another brief 'dip' or a fully fledged decline.
It would be worth keeping an eye on it.
Regards
Andrew Pearce
Western Australia
Looking for regular periods of dips in the RCB star lightcurves can be fun but frustrating. The only regularity that has been found is that at least some of the stars always start their declines at the same phase of their stellar pulsations. But they don't form dust during every pulsation so it is never very regular. I am attaching the lighturve of RS Tel before and after the last major decline. The red points are a 10 point smooth of the AAVSO data and the blue points are the ASAS photometry. The pulsation period of RS Tel is about 40 days but the amplitude is only ~0.1 mag. You can see it clearly in the ASAS data. But there are no regular dips other than those. The bigger semi-periodic dips are probably little dust formation events.
Geoff
Hi All
RS Tel appears to be continuing it's slow fade. On June 11.655 UT, I made it mag 11.2.
Regards
Andrew Pearce
Hi Andrew
A major fade here for sure. I have it all the way down to V=16.47 on July 25.54 UT. VSX currently lists the minimum as 15.34V so that'll have to be ammended.
By the way, NSV 10529 in the same field is at V=13.22 ... basically just as Overbeek (OB) reported it to be back in September of 1982. What a great observer he was.
Is it my imagination or are there ALOT of RCBs currently in deep fades at the same time.? It might be a good idea if, collectively, there was an 'RCB Status' page somewhere where we might update online what's going with specific variables. There's ALOT going on. Observers and theorists, both professional and amateur might like to have a dedicated page somewhere that was updatable in real time. Certainly would be useful to me for obs planning !
kind regards
Steve
Doug Welch has begun setting up an RCB star webpage. Stay tuned!
Geoff
Hi Steve, Andrew and Geoff,
Regarding an RCB Status page, not so long ago I used to send a near monthly “RCB Recent” message through the vsnet-rcb mailing list. This would simply list my most recent end-of-month observation for each of the mostly southern RCB stars on my working list along with a remark as to whether the star was at maximum, minimum or somewhere in between.
The aim here was to provide a regular update on the current status of each star rather than just reporting the onset of a decline and thereby assist those who may be planning observations of these stars at different stages.
If nothing else, it provided alternative reading to the lists of faint CVs in outburst but, unfortunately, as there appeared to be little or no interest in this I stopped sending them.
It would certainly be good if Doug Welch were to create a dedicated RCB web page. There appears to be a number of recently recognised RCB stars within reach of amateur observers and about which little is currently known.
Tks.
Peter Williams WPX
Heathcote NSW
Hi All
it appears as though RS Tel may be recovering from it's recent deep but relatively short minimum. Last night I observed it as being above 14th mag. My observations are not yet in the AID.
Regards
Andrew Pearce (PEX)
Yep, it's definitely brightening. I made it 13.2 tonight.
Regards,
Dave (BLD)