Sun, 05/20/2018 - 09:13
SDSS J141118.31+481257.6 (IBWD+UG)
This AM CVn-type variable is currently undergoing its first recorded outburst (12.6 mag, detected by Tadashi Kojima on 2018 May 19.514 UT). Time-resolved photometry is urgently required.
SDSS DR14 shows SDSS J141118.31+481257.6 to be a qso with z = 0.13474. Spectrum: http://skyserver.sdss.org/dr14/en/get/SpecById.ashx?id=1881381550927407…
So is this a MW variable or a qso?
SDSS J141118.31+481257.6 is an AM CVn-type variable, currently undergoing a WZ Sge-type (super?)outburst.
AAVSO Alert Notice 635 announces an observing campaign beginning immediately on the AMCVn system SDSS J141118.31+481257.6. Please see the notice for details and observing instructions.
Many thanks, and Good observing,
Elizabeth O. Waagen, AAVSO HQ
SDSS J141118.31+481257.6 now has comps down to 18.9V; be sure the VSP Mag limit for your chart FOV will specifity a limit of 19 magnitude.
Looks like SDSS J141118.31+481257.6 is brigthening. Just measured at mag 16.6, confirming data submitted by TRT.
I've uploaded some data, but will probably update it after I take some new flats tomorrow morning. Note that my data is quite noisy, with instrumental magnitudes for the target on the order of -10.6 (C8 + Atik 414ex under heavy light pollution...).
I'll try to run a time series all night long and process everything with good quailty flats tomorrow evening or Saturday (I don't have a super-automatic pipeline for processing my data).
Yes, I can confirm its brightening again. We found a fast brightening from 17.5mag (two nights ago) to 16mag (last night). It will very likely be very bright again in a day or so.
Time-series phtometry (to resolve superhumps) and regular monitoring is urgently needed.
AAVSO Alert Notice 636 has been issued on SDSS J141118.31+481257.6 and its rebrightening and possible superoutburst. Please see the notice for details and revised observing instructions (revised from AAVSO Alert Notice 635).
Many thanks, and Good observing,
Elizabeth O. Waagen, AAVSO
I viewed this object last night with my 32" Dob and got a visual reading of ~13 mag! I used check stars: 139, 127 and 111. Excellent seeing with the object at the zenith. Any one else getting this visually?
I had a quick look at one image from my current time series and I measured it at 13.1 (with 127 as the comp star).
I've been taking time series of ~5 hours with 30 seconds exposures every night now. But since I'm in the process of switching to a better pipeline for the data processing, it might take a bit some time before I upload my data.
Last night I got m = 13.0 Vis using comp stars 133 and 129. I will try again tonight if it stays clear.
Thanks jfgout, I've submitted my data point to the AAVSO. Hopefully, I'll get another look-see on this object if the wind calms down up here in Flagstaff. :)
Come down to Phoenix, no wind here ... but light pollution of coure (and it's getting really hot).
Looks like SDSS J141118.31+481257.6 has been dimming incredibly quickly!
A quick measure at 04:32am UTC (June 8th) gives it at magnitude ~15.7. This is a very rough measurement, as I had my exposure time setup expecting to measure something around mag ~13.5 (and now my SNR is terrible).
Now, here is the crazy part. While I was setting up my gear and centering the target in the CCD, I could see it on my screen and based on the other stars in the field of view, I would say it was about mag 14 (this is just a very rough estimation based on looking at the image on the screen, not taking a real measurement). And while I was using a series of 10sec exposures to finely center the telescope on the target, I basically saw the target disapear. I wish I had saved the images that I was taking during the setup/centering! This happened around 4.20am UTC.
Hopefully someone else was taking a time series at that time and will have some good data on this extremly fast dimming.
Any other observers looking at SDSS J141118.31+481257.6 tonight?
I reported 15.347 CV at 2018-06-08 00:15:11. Will continue observations tonight.
I concur jfgout! I got a visual reading of 15mag last night with the 32" @ 23:20hrs. I used check stars 139, 141. Interesting about the possible disappearing...I plan on spending a lot of time on this object tonight...fun times:)
Thanks guys for the confirmation. Based on Juan Pablo (DJUA)'s observation, I'm starting to doubt my observation of the star fading by ~2mag in a dramatic 1 or 2 minutes. I was very tired while seting up the scope, so maybe my brain was seeing things that were not there. I wish I had recorded the 10sec exposures I was taking to align the telescope with plate solving...
I'll keep observing tonight with increased exposure time. And some day I'll find the time to process all the time-series data I've accumulated in the past 6 days.