AAVSO Alert Notice 532 requests multicolor time-series observations of the enigmatic variable KIC 8462852. Please see the Alert Notice for details and instructions.
Many thanks and good observing!
Elizabeth Waagen, AAVSO HQ
I'm getting this message in Vsp: "There were errors in your form. Fix these issues to continue:
The correct name is KIC 8462852 without the leading zero.
We'll fix this.
VSX can find KIC 08462852 with or without the leading zero and as long as there are at least the correct number of spaces between the parts of the star name.
However, VSP is sensitive to the leading zero and to the number of spaces. It looked as though you had three or four spaces after KIC, and that caused VSP not to be able to find the star (I tried VSP with the name that way and that's what happened). Also, now that Sebastian has changed the VSX entry, please don't use the leading zero.
Thanks for wanting to observe this interesting star!
I mis-spoke in my previous post. Sebastian did not change the VSX entry for KIC 8462852 (KIC 08462852). The entry was submitted without the leading zero - and, as I was the person who did that, I should have made the Alert Notice conform to that format! My apologies all around.
The Kepler data pages do not use the leading zero and most publications with Kepler data do not use it either.
Since the number of stars reaches 8 digits and SIMBAD's Dictionary of Nomenclature of Celestial Objects shows the format KIC NNNNNNNN, sometimes a leading zero is indeed used. As a result we have a mix in VSX where there are many more stars without the leading zero but this is not something consistent because we usually take the ID from the publications.
We have added the two names now so VSP will make a chart no matter what name you enter.
For other KIC stars, whenever you don't get a chart with one of the name versions try the other one.
Thanks for the clarrification! I'm usually too lazy (and not accurate) to input these Kepler variable names, so I cut & pasted the name directly from the Alert Notice 532; with no leading or following spaces. I tried without the space but did not try without the 0. Although I got a chart uning the object's RA/Dec coordinates, I'd rather have a chart with everything labeled before I reduce the data in Maxim and transform the VBI magnituded in TA. Thanks again!
Will there be any U magnitudes given for the comp stars around KIC 08462852?
I remember reading that it would be desirable to show U to Ic differences in magnitude
to determine whether KIC 08462852 is surrounded by either large or small debris particles.
Los Angeles, CA
Dear AAVSO observers,
I want to express my gratitude for your efforts to monitor the mysterious star KIC 8462852! Your contributions are critical in determining what is causing its unusual variability!
I would like to take a moment to prepare you for when the dipping will happen -- it is fair to say that we have no idea when this could be! The Kepler light curve spanned 4 years, and this object was dipping only for a very small fraction of that time. When the time comes that we observe KIC 8462852 to start dipping again, we will be able to trigger a larger follow up network of observations in order to find out more information on what is causing the dips. However, it is important to remember that by knowing when this object is *not* dipping also provide constraints on the system.
Interesting - your choice of words implies greater confidence in the likelihood of further dimmings than was perhaps apparent in your paper, at least under the comet scenario. Either way, compliments on brewing up such a storm:)
A quick look on LCG for this star shows a 0.2-mag drop in V on Oct 31-Nov-1
Error measures or real drop?
I looked at the light curve that you posted. I also looked at a 30 day light curve, and looked at a light curve in all 4 colors. Also expanded on the night in question. These are the observations made about this data;
1. The observer with the lower light curve, had an observation on 10/25 which was right on the other observers.
2. On 10/30 00:00, there are two observers separated by 0.1 mag, indicating that Transformation may not have been done.
3. If I look at the data on JD 2457327, the lower light curve shows a discontinuity at roughly mid point. This suggests a dec flip perhaps. It also suggests scattered light issues. Since this observer was right on several days earlier, I wonder if there was an interferring moon on the night in question? Just looked up and the full moon was on the night of JD 2457327--ie Oct 31.
4. There is no corroborating data in B, R, or I that also shows the dip.
5. Other data that night at the same time does not show the bias change. Perhaps the questionable data has high extinction compared to the other data.
I don't think this stands up as a real effect. Also remember that this behavior is within +/- .016 mags one sigma (0.1 mag peak to peak) which is about all that can be expected. To do better we would have to have all the data Transformed, Use the exact same comp/ref stars, and reduce stray light to remove dec flip anomalies, check for extinction effects, etc.
The extraordinaty Tabby Boyajian's TED talk on KIC 8462852 is online:
AAVSO observers are mentioned in the end of her talk. Follow-up observing is really important, especially as we try to understand the nature of this object. Please add it in your observing list.
Best wishes - clear skies,
At first I thought (of course) "F-type sprectrum, aperiodic dips, must be another UXOR!", but there doesn't appear to be any IR excess from a disc. Purely on a light-curve basis this looks like a small-amplitude RCB star. How does the spectrum compare as regards elements that could be a source of RCB-type veiling?
Hey, good question!
In the paper (http://arxiv.org/pdf/1509.03622.pdf) We compared this star to a RCB type and found it is inconsistent with our observations of KIC 846.
1) RCB light curve dips are typically quick ingress & slow egress - opposite to what we observe for KIC 846.
2) RCB stars are also a very evolved evolutionary state, meaning that they have low surface gravity which can be seen in the spectrum - the spectrum for KIC 846 tells us the star has not evolved at all.
PS: yes, the lack of IR excess gives trouble to most theories!
AAVSO Alert Notice 542 re-iterates the request for continuing time-series observations of KIC 8462852 = KIC 08462852 (either name may be used to create charts, plot light curves, or submit observations). It also includes the links to the MNRAS paper by Dr. Tabetha Boyajian et al. and to her TED talk.
In the second version of the article about discovery Tabby's star there is speculation of a possible 48.4-day periodicity of eclipseshttp://arxiv.org/pdf/1509.03622.pdf
May 4 this year AAVSO observers have detected a new transit. Interestingly, the new transit also in accordance with 48.4-day periodicity of eclipses:
As the 48.4-daily periodicity of work, I think, observers AAVSO should focus specifically on the 48.4-day window to find new transits. Also, and on 24.8-day intervals (some small transits in photometry telescope Kepler observed near half 48.4-day intervals).
Detection frequency of transits probably makes version comet swarm untenable. It remains to three possibilities:
1) Unknown type of periodic variable star
2) Eclipse is a variable dust tail evaporating not-transit planet (like volcanic Jupiter's satellites - Io).
3) Eclipse is a constellation of artificial astroengineering with multiple distance between each other. Like the NASA satellite constellation - A-Train.
The Planet - And it´s orbiting Moon(s)?
To me it is very likely that the data shows the orbiting planet and it´s Moon/Moons which can explain the different signals as the moon (s) orbits the planet, changing orbital positions around the planet and thus giving different profile signals.
To all of the observers who have contributed to this crazy star's light curve for the past 13 months -- THANKS for all your hard work and dedication to the project!
Over the next few weeks, the star will be slipping away from our view. I hope that your observations continue when the star becomes visible again early next year!
And if you are ever in Baton Rouge, LA, feel free to reach out and connect. First drink is on me!
No worries Tabby, I can see it all year round from Ireland and will raise the alarm if it disappears:)
counting on you!
it must be fun living in Ireland then. :D do you ever sleep because of it? or you're all on sleep meds like ambien? :D
We are requesting for observers at high latitudes to make an extra effort this month - the star is out of reach for most of the world but not for you! Nightly observations in as many filters as you can. Message me if you have any questions and keep up the good work!
I'm at latitude +45 (Atlantic Canada) and am still observing it. Looks like there are only 4 of us in the last month. I am taking B and V. If R and/or I are useful let me know and I'll add them.
--- Dave LDJ
Yes please add the RI filters! The composition of whatever is blocking the light will be wavelength dependent. We can get the most info out of colors that are furthest apart in wavelength. TY!
I can see it from my home obs for about an hour or so in early mornings for another 2-3 weeks or so.
Can shoot R, G, B or, optionally, 3nm SII, OIII, Ha, or NII as well. Would such short observation time frames be of any value?