I think the (possible) companion star is a bit too faint for Gaia.
Quote from: as58 on 12/11/2016 02:49 PMI think the (possible) companion star is a bit too faint for Gaia.Very likely, which is a shame: we'd be much more likely to be able to see the orbital motion on the M companion than on the A3V primary (if they're bound) ...--- Tony
Quote from: jebbo on 12/13/2016 10:37 AMQuote from: as58 on 12/11/2016 02:49 PMI think the (possible) companion star is a bit too faint for Gaia.Very likely, which is a shame: we'd be much more likely to be able to see the orbital motion on the M companion than on the A3V primary (if they're bound) ...--- TonyA3V?
Spectral type A3, luminosity class 5 (main sequence dwarf). The Sun is G2V. The spectral type sequence reflects temperature, and goes (from hottest to coldest) OBAFGKM (I am not including the brown dwarfs). Each spectral type goes from subtype 0 to 9 (e.g., G0 is warmer than G1, etc., then G9, then K0). Luminosity classes go from I to V, in order of decreasing luminosity. It depends on the temperature and radius of the star. Supergiants are the class I, dwarfs (normal core hydrogen burning stars) are V.How we ended up with those letters (OBAFGKM) is a fascinating story, but way beyond the scope of this post!
I meant that I didn't think the primary is an A star and now that I've checked, it seems to be F3V.
Jason Wright @Astro_WrightInaugural K-band #BreakthroughListen observations underway at 22 GHz at @GrnBnkTelescope. Target:@tsboyajian's Star. #SETIMoist Chure3hMoist Chure @MoistChure@Astro_Wright @GrnBnkTelescope @tsboyajian How long till SETI analyzes the data?Jason Wright3hJason Wright @Astro_Wright@MoistChure @GrnBnkTelescope @tsboyajian First we have to get it to PSU, then I have to learn the software. Timescale is weeks to months.Jason WrightJason Wright – @Astro_Wright@MoistChure @GrnBnkTelescope @tsboyajian Timescale to publication much longer. Unless we see something obvious; then maybe not so long
Hello Backers,Edit: Over the past week, a few papers were published on WTF. Jason Wright blogged about the first two, you can view that discussion here (including links to the original papers). The third paper has only been 'submitted' to the journal, meaning that it has not gone through the peer review process necessary for publication. We will discuss the contents on this once it has been accepted. Be sure to visit the sub-reddit (which now has over 4,000 subscribers) if you want to discuss more with the community. Updates to the ObservationsAs discussed in the last report, we have modified our observing strategies to optimize data quality. This was a concern because the image was saturating because the defocus command not properly executing. When this happened, the scatter increased in the light curve, an effect we want to minimize. To remedy this, we have now selected settings that will work whether the defocus command executes or not. Just after this change in the schedule request we were reviewing the data and saw something.We saw the data points trending downwards - like the start of a dip. But this trend was not downwards enough to be a sure thing (it was too soon), especially if we considered the measurement errors (which is a must!). Furthermore, we only saw the downwards trend in one of the three filters at only at one of the observatory sites (what is plotted in the figure above). OK, so nothing significant, right? Right? Well, we weren't so confident about whether or not it was real because we couldn't explain what was causing the trend we observed. And if we couldn't explain the data, we couldn't let our guard down. So here we are frantically checking the LCO scheduler to see when new data was expected to be taken. If the dip trend continued at the same rate, it was the next observations that would confirm it.At the same time we are asking ourselves hundreds of questions. Why would a trend like this appear only in one filter at one observing site? Was is astrophysical or instrumental? Did a thin layer of clouds roll in that affected the conditions? Did the image get contaminated by scattered moonlight? Did we just not understand our errors well enough? Is there some unknown source of correlated noise in the data?And then Tyler triumphantly announced - this comparison star is BAD! It was one of the comparison stars that we have been using all along. But after the configuration change to address saturation, the conditions were just barely right (or wrong) enough to affect the one star enough to make it look like there was a dip in the data. Removing the bad comparison star fixed everything, and the data now lines up with the rest of the curve to reveal nothing but a flatline. I guess that is good. For now. We remain patient. This highlights the odd nature of astronomy (and science as a whole), occasionally things just don't work right even though they should.On the management side of things, we are now set up with a new computer which we have named Toph. Tyler chose this name because we wanted a theme which is expandable if we ever need future computers and the computer generally won't have a monitor attached. Toph is from Avatar: The Last Airbender and is a blind, but fierce fighter. Blind, no monitor. Look, we're scientists first and good at naming things somewhere further down the list.This is where all the data will be stored locally. Each image is about 7 megabytes in size, but throughout this campaign we will take thousands (possibly over ten thousand images). At the moment we almost have 20 GB of images! From these images we will have Toph automatically extract and produce the light curves and then email them to us and send alerts if a dipping event occurs. This is largely possible with the photometry code developed by Rachel Street and the other astronomers at LCO.Happy holidays to you all,~the entire WTF team Thank you once again for your support!
I meant that I didn't think the primary is an A star and now that I've checked, it seems to be F3V. Not that there's anything wrong with your explanation
Secular Dimming of KIC 8462852 Following its Consumption of a Planet
The Kepler-field star KIC 8462852, an otherwise apparently ordinary F3 main-sequence star, showed several highly unusual dimming events of variable depth and duration. Adding to the mystery was the discovery that KIC 8462852 faded by 14% from 1890 to 1989, as well as by another 3% over the 4 year Kepler mission. Following an initial suggestion by Wright & Sigurdsson, we propose that the secular dimming behavior is the result of the inspiral of a planetary body or bodies into KIC 8462852, which took place ~10 to 1e4 years ago (depending on the planet mass). Gravitational energy released as the body inspirals into the outer layers of the star caused a temporary and unobserved brightening, from which the stellar flux is now returning to the quiescent state. The transient dimming events could then be due to obscuration by planetary debris from an earlier partial disruption of the same inspiraling bodies, or due to evaporation and out-gassing from a tidally detached moon system. Alternatively, the dimming events could arise from a large number of bodies comet- or planetesimal-mass bodies placed onto high eccentricity orbits by the same mechanism (e.g. Lidov-Kozai oscillations due to the outer M-dwarf companion) responsible for driving the more massive planets into KIC 8462852. The required high occurrence rate of KIC 8462852-like systems which have undergone recent major planet inspiral event(s) is the greatest challenge to the model, placing large lower limits on the mass of planetary systems surrounding F stars and/or requiring an unlikely probability to catch KIC 8462852 in its current state.
Thing is we can keep coming up with theories on this forever but only more data is going to resolve it. ..
I’m glad to see this scenario fleshed out so well. I suspect that there are ways to save the model by finding ways to make sort of event occur more frequently—perhaps by making the merging/dips more frequent by getting a chain of material from a single massive object—so I’m optimistic there’s more to this. I’d say this paper has moved the “post-merger return to normal” scenario from “unclear” plausibility to something like “less plausable,” or even higher.
Yeah, like a planet, swallowed or crushed or whatever, covers 22% of the star's light.