(cba:news) YZ Cnc, oops, priority now changed
jop at astro.columbia.edu
Wed Jan 25 16:36:24 EST 2017
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.
-------- Forwarded Message --------
Subject: Re: YZ Cnc
Date: Wed, 25 Jan 2017 20:41:00 +0000
From: Knigge C. <C.Knigge at soton.ac.uk>
To: Joe Patterson <jop at astro.columbia.edu>, jk >> Jonathan Kemp
<jk at 155west.org>
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.
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!
> 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.)
>> 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?
>>> 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!
>>>> 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
>>>> 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!
Professor Christian Knigge
Physics & Astronomy
University of Southampton
Southampton SO17 1BJ
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