Hi CBAers,Just got this from Christian Knigge, who is organizing the YZ Cnc campaign. The X-ray satellites have pointing constraints, which are mostly - but alas not entirely - predictable in advance. Chandra can't look at that position for at least another 8 days. So demote YZ Cnc in priority until ~Feb 2. It's still a decent target, but short-ish time series will do, since the idea (until dense coverage starts in February) is mainly to construct a detailed record of the
daily pattern of eruptions. joe p -------- Forwarded Message -------- Subject: Re: YZ Cnc Date: Wed, 25 Jan 2017 20:41:00 +0000 From: Knigge C. <C.Knigge@xxxxxxxxxxx>To: Joe Patterson <jop@xxxxxxxxxxxxxxxxxx>, jk >> Jonathan Kemp <jk@xxxxxxxxxxx>
I'm so sorry -- I've just been told by Chandra Mission Planning that, actually, YZ Cnc is fully unobservable until at least Feb 5 and only partially observable between then and Feb 11. They've apologized for not saying this sooner, but of course I've already told all the amateurs to help with dense monitoring -- grrr... What that means in practice is that we really don't need data urgently until about a week from now, say Feb 2 or so. After that, all the stuff I said before is still true, i.e. really dense monitoring to catch the early rise is critical. Cheers, C On 24/01/17 15:16, Joe Patterson wrote:
Thanx. With that description, I'm going to encourage them to keep getting long time series. That will give them a decent baseline from which to judge rises in light (versus flickering). I don't understand "pre-confirmation"... but I don't think I need to. I'll ask them to submit data to cba-chat, so everyone can look at everyone else's data, taking advantage of the spread in longitude. If you get cba-chat (JOnathan, can you add Christian in case he doesn't now get it?), you'll see it too. Buena suerte! joe On 1/24/2017 6:06 PM, Knigge C. wrote:I'd really like to trigger on the very next outburst for which we have a chance. That's important also for the GOALS project itself (since YZ Cnc is one of the candidate targets for this), as the deadlines for this round are coming up... In practice, a trigger will require (i) super-early notification from the amateur community; (ii) confirmation from Chandra that the turn-around they can provide if we do trigger will be good enough for the science. (The second point is part of a special protocol we've got going with Chandra that should help us avoid a trigger that just narrowly misses outburst -- at the moment, the outbursts last only about 3 days, and the normal trigger window we're approved for is 1-3 days. So with sufficient bad luck, we could have been in trouble, but the informal "pre-confirmation" should avoid this.) C On 24/01/17 15:02, Joe Patterson wrote:Do you expect to trigger on the next normal outburst, or one more after that... or? If the next, I'll tell them to wait 5 days, then resume intensive coverage. That make sense? joe On 1/24/2017 5:53 PM, Knigge C. wrote:Hi Joe, sorry for not responding to your other email yet -- will do so asap (really snowed under just now). For now, I wanted to send oeragen a brief update on the YZ Cnc campaign that I just posted to the AAVSO and BAAVSS fora, to make sure we get the dense coverage we need to finally trigger that one. Not sure if this is worth sharing with the CBAers or not... Thanks for all your help with this! Christian ======================================================================= Hi all, I thought I'd provide a brief update on the campaign, mainly to say thanks for all the help so far and also to beg for continuing -- ideally even denser -- coverage. For our Chandra ToO observations, we need to catch YZ Cnc somewhere near the peak of a normal outburst. This is obviously quite difficult, given how short they are. I *almost* triggered on the first normal outburst after the last super, but it turned out I was in transit from the UK to the USA at exactly the time I would have had to be doing this. Murphy's Law. In any case, in order for this trigger to work, super-early notification of the start of an outburst is critical. Only amateur astronomers will be able to provide that for us. We have a special protocol in place with Chandra that will hopefully ensure that our trigger is successful, but it really rests *crucially* on that early notice. So really dense coverage of the rise and early notifications are central to our entire program. Again, thanks to all who have already contributed, but please keep going -- the campaign is still going, and I will definitely let you know once we have triggered and we are done. In the absence of such a note from me, you can assume that we have not yet been able to find trigger the X-rays early enough, so our attempt to get this will continue until we do. I am really grateful for all your help -- campaigns like this would be impossible without you! Cheers, Christian ========================================================================
-- =================================================== Professor Christian Knigge Physics & Astronomy University of Southampton Southampton SO17 1BJ ==================================================== ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing listshttps://cbastro.org/communications/mailing-lists/