(cba:news) V339 Del and UX UMa

Joe Patterson jop at astro.columbia.edu
Wed Jul 8 22:38:43 EDT 2015


Yeah, V339 Del appears to be a loser.  Nice performance at other 
wavelengths, but pretty flat in the optical.  Time to quit at optical 
wavelengths.

And for that matter, time to quit on UX UMa (even for the diehards). 
The periodic signals continue to amaze, but the runs are getting too 
short, and it's time to move on.

IGR 1955+00 remains awfully interesting!  And some time series on V404 
Cygni would be mighty nice too.

joe


On 7/8/2015 10:31 PM, Jim Jones wrote:
> Enrique
>
> Then I won't bother making a run to link up with Davids.
>
> Jim
>
> On 7/8/2015 5:28 PM, Enrique de Miguel wrote:
>> Jim,
>>
>>   David is using V filter.
>> With the current data, no modulation comes up in the light curve.
>>
>> Enrique
>>
>> On Jul 9, 2015, at 2:00 AM, Jim Jones wrote:
>>
>>> What filter David?
>>>
>>> Jim Jones
>>>
>>> On 7/8/2015 4:21 PM, David Cejudo wrote:
>>>> I am actually following V338 Del as Enrique asked me to.
>>>> I may change targeta if neded, though.
>>>>
>>>> David Cejudo.
>>>>
>>>>
>>>>
>>>>
>>>>> El 8/7/2015, a las 16:08, Joe Patterson <jop at astro.columbia.edu>
>>>>> escribió:
>>>>>
>>>>> Hi Donn et al.,
>>>>>
>>>>> Thanx for the details.  Yes, I think it is a "super-period" around
>>>>> 12 hours or so... but the precise value will depend on filter
>>>>> issues (since the AM Her stars often show really bright I emission
>>>>> due to cyclotron emission).  The basic period seems to be 81
>>>>> minutes, a very plausible Porb - but the star is pretty remarkable
>>>>> for its super-period, and for its huge variations on a timescale of
>>>>> just a few seconds (or maybe even less than 1 sec!).
>>>>>
>>>>> As Enrique says, we'll be able to splice these light curves
>>>>> together better when the star transits closer to local midnight.
>>>>> Shawn
>>>>> (easternmost USA observer) and Josch/Arto (Chile observers) will be
>>>>> in a good position to splice with Spanish observers (Enrique,
>>>>> David, Tomas).  And Gordon (AU) may be able to splice with Berto (ZA).
>>>>>
>>>>> joe
>>>>>
>>>>>> On 7/8/2015 9:41 AM, Donn Starkey wrote:
>>>>>> Joe, et.al.:
>>>>>>
>>>>>> My runs on IGR J19552+0044 were performed using a clear filter.  The
>>>>>> comp star was AAVSO 145 and the K star was AAVSO 148.  I used the R
>>>>>> magnitude for these two stars:
>>>>>>
>>>>>> C star    AAVSO 145     R mag 14.258
>>>>>> K star    AAVSO 148     R mag 14.292
>>>>>>
>>>>>> Exposure times were at 120 sec for each night of observation.
>>>>>>
>>>>>> Because of the placement of this star [or maybe because of my
>>>>>> placement
>>>>>> in relationship to the star] I started observing a very high air
>>>>>> masses.  Originally, I had thought that the star was brightening
>>>>>> during
>>>>>> the run due to lowering air masses, but subsequent runs shows that
>>>>>> the data did not appear to be effected by the air mass.  Is this a
>>>>>> long
>>>>>> term period fluctuation on the order of a multiple of ~12 hours?
>>>>>>
>>>>>> I am out of town until the 17th, but will continue observations on
>>>>>> this
>>>>>> target when I return home....unless directed otherwise.
>>>>>>
>>>>>> Donn
>>>>>>
>>>>>>
>>>>>> ----------------------------------------
>>>>>> Donn Starkey
>>>>>> donn at starkey.ws <mailto:donn at starkey.ws>
>>>>>>
>>>>>>
>>>>>>
>>>>>> ------------------------------------------------------------------------
>>>>>>
>>>>>>     *From:* Joe Patterson <jop at astro.columbia.edu>
>>>>>>     *To:* Gordon Myers <gordonmyers at hotmail.com>; Enrique de Miguel
>>>>>>     <edmiguel63 at gmail.com>; donn at starkey.ws
>>>>>>     *Sent:* Monday, July 6, 2015 11:06 PM
>>>>>>     *Subject:* IGR J19552+0044
>>>>>>
>>>>>>     Hi guys,
>>>>>>
>>>>>>     Helluva entertaining star this is!  The 81 minute period is very
>>>>>>     obvious, of course, and so are the super-fast (<5 s actually)
>>>>>>     oscillations in the "high state".  But I'm having trouble
>>>>>> putting these
>>>>>>     time-series on a common scale.  Because of the star's equatorial
>>>>>>     location, it's hard to get overlap - and we don't have any strict
>>>>>>     overlap.  In addition, there's some reason to believe that the
>>>>>>     brightness of the star is very different in V versus R versus
>>>>>> I. (Not
>>>>>>     known, but very possible.)
>>>>>>
>>>>>>     So can you state in detail how you derived your magnitudes
>>>>>> (even if you
>>>>>>     did in your original submission), and then copy all of us on
>>>>>> it?  I
>>>>>>     sure
>>>>>>     would like to figure out that longish period or quasi-period
>>>>>> that seems
>>>>>>     to be present (around a day?).
>>>>>>
>>>>>>     As you know, most CVs look pretty much the same at any
>>>>>> wavelengths near
>>>>>>     BVRI (their colors are usually close to B=V=R=I=0).  But the
>>>>>> magnetics
>>>>>>     (AM Hers) are often much brighter in I, because of cyclotron
>>>>>> radiation.
>>>>>>        You could perhaps check this by taking some data in I.
>>>>>>
>>>>>>     joe
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