Chat Transcript: Thursday


>  Mike Toillion: (4/11/2013 09:04) Welcome everyone! Please feel free to enter any questions for the presenter here. We will read them aloud during the Q&A period.
>  Anbar: (09:17) Want to tweet? #stellarstoich
>  Doug Whittet (RPI/NYCCA): (09:18) The ulr shown on the webpage is wrong: http should be https
>  Mike Toillion: (09:18) Hi Doug, either should redirect to the proper site.
>  Doug Whittet (RPI/NYCCA): (09:20) Didn't appear to be linked! I had to copy/paste and then dicovered the error.
>  Estelle Dodson: (09:21) ah, okay, thanks Doug, we'll follow-up and see if we can make it a link.
>  Mini Wadhwa: (09:24) Are the observational errors at 95% confidence limits?
>  Natalie Hinkel: (09:25) Typically yes, with that sort of accuracy there would almost have to be.
>  Everett Shock: (09:29) Thanks Patrick!
>  Anand Thirumalai: (09:31) In the abundance data, are there chemical compounds that do not show up in the spectra, which could contribute to the errors?
>  Patrick Young: (09:34) Anand, in the stars we are discussing the temperatures are too high for molecular species to form.
>  Anand Thirumalai: (09:36) Ah okay! I see!
>  Anand Thirumalai: (09:37) Thanks Patrick
>  Erik Brugamyer: (09:40) Natalie: I would point out that continuum placement is one of the most important sources of differences between groups
>  Maggie Turnbull: (09:41) Anand, at high metallicities, certain elements have absorption lines that are contaminated by other species and have caused large errors in measurement.  For example Oxygen contamination by Nickel lines.
>  Mike P: (09:41) Erik, keep these things in mind, and we will get to that in the discussion in an hour or so.
>  Anand Thirumalai: (09:42) Thanks Maggie. These measurements are incredibly complicated then!
>  Melissa Morris: (09:43) Is anyone else having problems with major feedback on sound?
>  ASU A/V: (09:44) Is your mic muted?
>  Estelle Dodson: (09:44) not here, but if you are on a polycom or telephone and connect, you need to mute your computer speakers
>  Melissa Morris: (09:45) not connected through polycom or telephone.
>  Melissa Morris: (09:45) ...computer only.
>  Mike Toillion: (09:46) Hi Melissa, check to make sure that you dont have the meeting opened up more than once.
>  Mike Toillion: (09:46) This can cause an echo.
>  Melissa Morris: (09:47) may be a memory issue.  Only seems to happen if I try to do another task.
>  Inese Ivans: (09:54) No variation in input models?
>  Inese Ivans: (09:54) or in assumptions in alpha enhancements?
>  Inese Ivans: (09:54) that s/b variation of metallicity in input models
>  Elena Nickson: (09:55) Was there a difference in stars that were normalised by an automated code compared to by eye? Or did everyone use an automated code?
>  Mike P: (09:55) Both are used, and when we discuss the HW examples, we can see who did what
>  Elena Nickson: (09:55) Thanks :-)
>  Daniel Huber: (09:59) The Teff dependence of the asteroseismic loggs is quite small, so typical uncertainties are more like ~3% in radius, ~7% in mass and 0.01 dex in logg
>  ASU A/V: (09:59) Inese, has your question been answered?
>  Maggie Turnbull: (10:01) I would like to ask Natalie a question via telecon, I'm on the line.
>  Mike Toillion: (10:02) OK, thanks, please make sure that Adobe Connect is muted when you speak.
>  Mike Toillion: (10:02) Go ahead maggie
>  Inese Ivans: (10:02) to ASU A/V: more a comment and can save it to lateer
>  ASU A/V: (10:02) ok, thank you
>  Inese Ivans: (10:04) we can account for nickel blending in spectrum syntheses calculations, deriving a good abundance from forbidden O.
>  Mike Toillion: (10:04) Thanks, Maggie!
>  Elena Nickson: (10:04) Did the different groups select different numbers of lines to measure?
>  Inese Ivans: (10:05) however, there's a problem in getting the SAME O abund from different features (forbidden, molecular, redder featers all yield different abunds in O)
>  Elena Nickson: (10:06) awesome thanks!
>  Anand Thirumalai: (10:31) Question for Natalie: How good is the LTE assumption in these atmosphere models (MARCS and ATLAS)? This may break down if there are (say) chromospheric components in the atmosphere, or if there are non-equilibrium processes, to give an example: acoustic wave heating in the atmospere. Do you know if there are efforts underway to deal with breakdown of LTE in these atmosph ere models?
>  Inese Ivans: (10:32) nice point, erik
>  Natalie Hinkel: (10:34) Anand - There are a number of papers that look at the differences between LTE and NLTE effects.  From what I can tell (and obviously in general), only some elements vary when taking into account NLTE.
>  Anand Thirumalai: (10:34) Thanks Natalie
>  Natalie Hinkel: (10:35) As far as the additions into the atmosphere models, people appear to be making the adjustements themselves.  In other words, it's much easier to do LTE as opposed to NLTE analysis.
>  Anand Thirumalai: (10:38) Thanks Natalie, I agree it's probably not straight-forward to consider  NLTE.
>  Patrick Young: (10:38) Anand, solar atmosphere models do address non LTE conditions as well as the 3D hydrodynamics. they find that for some element both effects are quite significant. For O, for example, emission from material at different temperatures moving up and down in convective cells have different line shapes than anything you get from a 1D mixing length atmosphere with a single micro turbulence parameter. That gives rise to big differences in solar abundance determinations in the last ten years.
>  Cayman Unterborn: (10:38) In regards to C, it's not just C/O that matters the most, you need to take into account the other rock building cations (Mg, Fe and Si). Mineral physics experiments have shown that Fe will oxidize before C, thus if all of the O is consumed by converting Fe to FeO (which gives you enough excess Fe to create a core), then any excess C will be present as graphite/diamond in a planetary mantle. It doesn't take much diamond to begin to increase the viscosity profile of a mantle and can shut down convection. The high C/ O planets (Bond et al., 2010) predicted around these stars ~4-5 times above this threshold. So we don't need much C after all to have a "carbon planet" in a geodynamic sense.
>  Anand Thirumalai: (10:43) Thank you Patrick. It's very challenging problem. It's curious that only certain elements are affected by LTE vs NLTE. I wonder how much this changes from star to star?
>  Jason Curtis: (10:43) i haven't exactly been following the entire chat log, but i'd like to point out that in addition to the different numbers of lines used by various groups, the Valenti & FIscher (2005) SME method specfically fits for log gf values for any lines not well matched to the Solar spectrum, assuming (somebody's) Solar composition and the standard atmospheric parameters.
>  Jason Curtis: (10:44) ...and adopts these new line data over that provided by VALD for these lines
>  Inese Ivans: (10:54) Natalie: please make the contact details available for the post-workshop contributions to the homework results.  Tks
>  Patrick Young: (10:56) for details of post-workshop homework contributions contact Mike Pagano atmichael.pagano@asu.edu. Thanks Inese.
>  ASU A/V: (10:56) We'll make sure she gets the message,
>  Inese Ivans: (10:57) she got the message :)
>  Elena Nickson: (11:00) What was the spectral region they were given?
>  Patrick Young: (11:04) 4800-6800A, I believe. spectra were from MIKE on Magellan.
>  Inese Ivans: (11:04) Q: What effect did the input metallicity have on the derived parameter results in the metal-rich stars?  (In metal-poor stars, the additional electrons contributed by a particular choice of input metallicity and alpha-enhancements can drastically change the electron pressure and, subsequently, logg, Teff. derived [Fe/H] for those who use the balance technique of homing in on parameters)
>  Elena Nickson: (11:04) Thanks
>  Elena Nickson: (11:17) Q: Were the equivalent widths all measured using automated techniques then?
>  Jason Curtis: (11:18) Have these groups also analyzed a Solar spectrum?
>  Inese Ivans: (11:18) Q: how much of the difference is driven by differences in EW measurements?
>  Jason Curtis: (11:18) SME would, since Ni would be synthesized along with O
>  Maggie Turnbull: (11:19) Great idea on the solar spectrum!
>  Jason Curtis: (11:20) VF'05 (valenti fischer) analyze 6 Solar (Vesta) spectra and derive parameter corrections to match derived values to actual Solar
>  Alicia Aarnio: (11:21) Can the presenters briefly comment on how the MIKE data were prepared before the different groups made their measurements?
>  Stringer: (11:22) I was struck by the large variation in [Fe/H] when the other atmospheric parameters were constrained to be the same. Does the agreement between/among groups in the mean [Fe/H] improve if you only calculate the mean using lines shared between/among groups? This might be a way to confirm that differences in the line lists are driving the variation.
>  Mike Toillion: (11:27) Hi Maggie, are you on the telecon?
>  Maggie Turnbull: (11:28) I have a question by telecon whenever appropriate!
>  Mike Toillion: (11:28) ok, let me re-connect the telecon, one moment please
>  Inese Ivans: (11:31) The iron they put in will affect the abundances they derive (due to electron pressure, etc).  The question was to what degree this changes the answers for metal-rich stars.  Tks!
>  Elena Nickson: (11:33) I would love that textbook!
>  Erik Brugamyer: (11:33) David Gray: "Observation and Analysis of Stellar Photospheres"
>  Jason Curtis: (11:33) great book
>  Jason Curtis: (11:34) ...but not a cookbook
>  Elena Nickson: (11:34) Yeah that textbook is my handbook to my phd
>  Elena Nickson: (11:34) agreed!
>  Jason Curtis: (11:35) 2005
>  Elena Nickson: (11:35) The book: http://www.amazon.co.uk/Observation-Analysis-Stellar-Photospheres/dp/0521066816
>  Maggie Turnbull: (11:36) Erik, does that textbook address the kinds of questions that are coming up here?
>  Erik Brugamyer: (11:36) In some cases, yes.
>  Patrick Young: (11:37) are there things like recommended line lists in Gray
>  Patrick Young: (11:37) are there things like recommended line lists in Gray?
>  Erik Brugamyer: (11:37) oh no!
>  Maggie Turnbull: (11:37) Is it just a matter of encouraging the community to follow the recipe therein?  Or is there a need for further comment?
>  Eric Gaidos: (11:38) The problem is that the community is still learning to "cook"
>  Eric Gaidos: (11:38) Deriving stellar abundances is still a work in progress.
>  Maggie Turnbull: (11:39) I can't believe papers without quoted uncertainties make it past a referee.
>  Inese Ivans: (11:40) IOW: How do the EW measurements for lines in common compare?
>  Elena Nickson: (11:40) How important do you think it is to automate the equivalent width measurement compared to by hand?
>  Eric Gaidos: (11:41) Spectrograph! Spectrograph!
>  Alicia Aarnio: (11:41) this speaks to the question of continuum placement... it's problematic for echelle spectra
>  Andrew Riddle: (11:42) I think assuming you and some other group place the continuum at the same level is not always the case
>  Alicia Aarnio: (11:43) just a word of caution for MIKE, specifically (I've been working with it for 3 years), the balmer orders, in the case of broad lines, will have wings that extend across multiple orders. So patching them together well is a very non-trivial task, and that would affect EWs of lines near/in those wings (and determination of log(g))
>  Inese Ivans: (11:43) Yes!
>  Alicia Aarnio: (11:44) plus, the blue chip has some scattered light issues (check raw data for 'rings' on the chip). those will cause trouble too with background subtraction.
>  Alicia Aarnio: (11:44) (i'll get back out of the weeds now, sorry for dragging y'all into them with me, there)
>  Eric Gaidos: (11:46) I've heard similar stories about MIKE but have no experience with it
>  Gerard van Belle: (11:46) What about constraints on TEFF?  These can be directly determined from optical interferometry for these nearby stars.
>  Jason Curtis: (11:47) MIKE R = 65k for 0.35" slit
>  Estelle Dodson: (11:47) online participants, please feel free to share any comments, notes, thoughts, etc.
>  Eric Gaidos: (11:48) As well as EBs where you know mass and radius (in principle)
>  Eric Gaidos: (11:48) ...although there are convection issues
>  Estelle Dodson: (11:48) you don't have to limit yourself to questions, we want everyone's input.
>  Daniel Huber: (11:48) seismology+EBs!
>  Gerard van Belle: (11:48) TEFF from optical interferometry gets down to ~25-40K errors
>  Daniel Huber: (11:48) don't have many yet though ..
>  Eric Gaidos: (11:49) TESS....
>  Daniel Huber: (11:50) yes, hopefully!
>  Joleen Carlberg: (11:51) Was everyone fitting gaussian profiles to measure their EWs or did some people allow for broader wings in some/all of their line?
>  Inese Ivans: (11:51) NIST - it's the most critical compilation.  However, the latest version might not be on-line -- send an e-mail if you don
>  Erik Brugamyer: (11:51) I use Voigt profiles, exclusively
>  Elena Nickson: (11:51) They could have done multiple profiles to fit for larger wings surely
>  Eric Gaidos: (11:52) Only one problem.....
>  Eric Gaidos: (11:52) bright astroseismo stars are evolved
>  Gerard van Belle: (11:54) Not from Kepler
>  Eric Gaidos: (11:54) THose aren't that bright
>  Gerard van Belle: (11:54) Ah I see what you mean
>  Elena Nickson: (11:54) Isn't the sun used as a zero point technically?
>  Daniel Huber: (11:55) if evolved = subgiant then yes, most of the Kepler seismo stars are evolved. there are a few dozen G-dwarfs though, a few of them are bright (16 Cyg A&B for example)
>  Eric Gaidos: (11:57) But I absolutely agree with Ed Young's comment..  There should be a list of "touchstone" reference stars (besides the Sun) that one measures at the same time and reports the results on.
>  Eric Gaidos: (11:58) i.e. metallicity standards
>  Gerard van Belle: (11:58) It would be excellent to hit some of these well-observed stars (eg. 16 Cyg A&B are good examples) that have asteroseismo plus TEFF and R pinned down from optical interferometry
>  Elena Nickson: (11:58) definitely
>  Gerard van Belle: (11:58) observed for abundances for these different groups , and see what the spread is with those 'external' parameters set for them
>  Daniel Huber: (11:59) I fully agree Gerard!
>  Gerard van Belle: (12:00) [all the intersting stuff is happening here in the chat room] ;)
>  Eric Gaidos: (12:00) Yes, and then when one publishes a paper on stellar abundances, one also observes and publishes the results on one or more of these reference stars.
>  Gerard van Belle: (12:00) Bingo
>  Eric Gaidos: (12:01) ...so that everyone has a basis for comparison
>  Elena Nickson: (12:01) that would be ideal
>  Estelle Dodson: (12:01) If you won't be returning to the workshop, please give us your feedback athttp://www.surveymonkey.com/s/www-stellar
>  Estelle Dodson: (12:02) we will be reposting this link and mailing it out to participants as well.
>  Inese Ivans: (12:04) ASU: Any chance your end can be muted during the break?  (For those of us who need to use our speakers for skypes?)
>  Inese Ivans: (12:05) Oops - I found the button. TKS!
>  Estelle Dodson: (12:16) The Stellar Stoichiometry workshop will continue at 12:40 MST (same as PDT)
>  Jeff Cuzzi: (12:20) moderator: please dial my videoconferencing system so I can get audio (?) thanks
>  Mike Toillion: (12:21) Hi Jeff
>  Mike Toillion: (12:21) I'm sending you a private chat now
>  Jeff Cuzzi: (12:22) hi mike, I just dialed in to the teleconference. Is that enough? I don't need to talk.
>  Mike Toillion: (12:22) ok sure
>  Daniel Huber: (12:32) i'm on the telecon ...
>  Mike Toillion: (12:33) If you are presenting during the Lightning talk session and are on the telecon, please announce yourself now please!
>  Cayman Unterborn: (12:33) I'm trying to figure out how to telecon with my webcam on my computer...
>  Daniel Huber: (12:33) I'll try to dial in again ...
>  Cayman Unterborn: (12:33) perfect, thanks!
>  Bekki Dawson 2: (12:34) I am on the telecon.
>  Cayman Unterborn: (12:36) Will there be video available from skype or will we do that through adobe connect?
>  Stellar Stoichiometry Workshop Without Walls: (12:37) If you like, you can start your webcam. I'm enabling your permissions now
>  Mike Toillion: (12:40) Welcome back, everyone! Feel free to chat here and post questions for the presenters.
>  Elizabeth Frank: (12:56) Have you thought about using U observations?
>  Cayman Unterborn: (13:01) Also, I'd like to add, that potassium is a volatile element, so even if we can measure it we can't say very well how much actually can make it into a terrestrial planets. Th and U on the other hand are refractory, so it's not too much of a jump to say that the stellar abundance represents the possible terrestrial planet abundance
>  Elizabeth Frank: (13:02) Cayman, were the heat production units of W/kg in your plots referring to kg of silicate material or kg of bulk solar system material?
>  Cayman Unterborn: (13:03) Good question. Normalized to the total planetary mass
>  Elizabeth Frank: (13:04) So that would include the mass of a core?
>  Cayman Unterborn: (13:05) These specific values are normalized to the mantle, so yes, it'd be silicate rather. U and Th are very incompatiable in melts so we shouldn't expect any in the core
>  Elizabeth Frank: (13:06) Thanks!
>  Cayman Unterborn: (13:06) In the Earth in fact, most of the U and Th is in the crust!
>  Elena Nickson: (13:10) Does anyone know the contact details for Johanna Teske?
>  Steve Desch: (13:12) Johanna's e-mail is jkteske@email.arizona.edu
>  Elena Nickson: (13:12) thanks!
>  Anand Thirumalai: (13:17) question for Nikhil: I assume that by sequestration you mean the molecules are just trapped within the droplets right?
>  Steve Desch: (13:24) Hi Anand: yes, Ne gets dissolved in the He droplets (and maybe so does O, in atomic form)
>  Elena Nickson: (13:24) Q: How do you know they are non hosts? Are the comparison stars ones that have been searched using RV?
>  Natalie Hinkel: (13:24) they aren't necessarily "non-hosts", they are more often just non-confirmed hosts
>  Natalie Hinkel: (13:25) aka background or field stars
>  Anand Thirumalai: (13:25) Hi Steve, thank you!
>  Elena Nickson: (13:25) fair enough
>  Anand Thirumalai: (13:30) Just a thought: in the pulsar hunting community these days they are employing machine learning algorithms for teaching computers how to identify pulsar pulse profiles. I wonder if something like that could be accomplished for estimating line widths?
>  Natalie Hinkel: (13:33) Anand - Are you suggesting an automated method for determinig line widths?
>  Anand Thirumalai: (13:33) essentially yes!
>  Anand Thirumalai: (13:33) but a more heuristic one that may exist presently
>  Natalie Hinkel: (13:33) Some of the eq. width finders are already automated.  The issue is how the various techniques deal with the continuum, which much more complicated than a pulsar's.
>  Natalie Hinkel: (13:34) Or line broadening or blending, etc.
>  Anand Thirumalai: (13:34) Ah I see!
>  Mike P: (13:36) Sousa (at U Porto) made a program ARES that finds EQW manually, but for the most part, measuring of EQW doesn't seem as important as continuum placement and line list
>  Elena Nickson: (13:38) Q: Do you think this is only for giant planet hosts or rocky
>  Natalie Hinkel: (13:38) Rocky planets are a lot more tentative as far as iron and any other element.
>  Natalie Hinkel: (13:38) Lars Buchave wrote a Nature paper on this at the end of 2012 - in general, we're not as sure on how to form terrestrial planets as giants.
>  Elena Nickson: (13:39) Yeah but there was a european paper written in 2009 which came to the conclusion that it was likely terrestrial planets influenced the stellar abundance
>  Elena Nickson: (13:39) Melendez e al 2009
>  Andrew Riddle: (13:40) rocky planets don't need to forma s quickly as giants do (before disk dissipation)
>  Natalie Hinkel: (13:40) See also Gonzalez-Hernandez 2010, Ramriez 2010, and Gonzalez-Hernandez 2013
>  Elena Nickson: (13:40) Interesting to note that Buchave doesn't acknowledge the Melendez paper exists
>  Natalie Hinkel: (13:40) there is a /big/ debate on this.
>  Elena Nickson: (13:40) I know - it's my PhD
>  Elena Nickson: (13:40) That's why I'm curious about others' opinions
>  Natalie Hinkel: (13:40) No worries.  I accdientally stuck my neck in it with a recent paper I published.
>  Elena Nickson: (13:41) Ooo what did you say?
>  Natalie Hinkel: (13:41) I cited one and not the other.
>  Natalie Hinkel: (13:41) i (foolishly) thought the debate was over since I hadn't nseen a recent paper, but that was my mistake.
>  Elena Nickson: (13:41) Ah. I've been keeping an eye on whether people have cited both and so far no-one has
>  Natalie Hinkel: (13:41) well, i will now!
>  Elena Nickson: (13:42) So will I when I finish this paper
>  Elena Nickson: (13:43) Trying to make sure I'm as certain as possible with my results before getting them out
>  Elena Nickson: (13:43) Taking a long time to avoid bad things happening
>  Natalie Hinkel: (13:44) that's not a bad idea overall.  many people are very opinionated, from what I've noticed.
>  Elena Nickson: (13:46) Oh yeah. Makes me slightly glad that there's no-one around in the UK doing this that can cause me to get over-opinionated with it. Dont know of many people doing this work in the UK
>  Natalie Hinkel: (13:48) well, there may not be a ton in teh UK, but there is a rather large group in Europe in general.
>  Elena Nickson: (13:48) Yeah I know - two different groups at least who have different opinions
>  Natalie Hinkel: (13:49) The beauty of science.
>  Elena Nickson: (13:49) I feel lonely in the UK hah
>  Natalie Hinkel: (13:50) I'm sure you'll be able to move around when you postdoc
>  Cayman Unterborn: (13:57) When you scale up to 10 Earth masses, mineral physicists have very little clue about how the equation of state of silicate species. How will this affect these underconstrained systems?
>  Steve Desch: (13:59) Cayman: stay tuned for Dan Shim's talk tomorrow!
>  Cayman Unterborn: (14:17) Why weren't this infalling asteroidal material also not blown away when the white dwarf blew off its planetary nebula?
>  Cayman Unterborn: (14:17) *wasn't
>  Natalie Hinkel: (14:19) I believe the implication was that the asteroidal material was accreted after planetary nebula - so during the lifetime of the white dwarf as a white dwarf.
>  Cayman Unterborn: (14:20) So is this just a probe of the ISM then and not really any former planets?
>  Natalie Hinkel: (14:21) I would disagree.  It's just that the accreted material was once a planet - as can be understood by the abundances that are observed.  If it was just the ISM, ther ewould be very litttle material and even that wouldn't be metal-rich.
>  Amanda Truitt: (14:22) Wouldn't the asteroidal material be of similar composition to that of any terrestrial planets in the system?
>  Natalie Hinkel: (14:22) It could be, yes, depends on where it came from.  A good key-off is the amount of material.
>  Natalie Hinkel: (14:23) His using the word "planetesimal" makes it seem that, while there is a large amount of material, it's not hugely overwhelming per a super-Earth, or something like that.
>  Natalie Hinkel: (14:24) Also - I don't think that the ligher, volatile elements would be found in an asteroid.  At least not in high quantities.
>  Cayman Unterborn: (14:24) How much infalling material (by mass) then would you need to infall to be able to measure these things?
>  Natalie Hinkel: (14:25) Enough to be spread evenly across the thin atmosphere of the white dwarf.
>  Anand Thirumalai: (14:28) Question for M. Jura: Let us say that we were to observe our Earth in the infra red from say in the atmosphere or even, for the sake of a thought experiment, say from elsewhere in the solar system, would we still say that bulk Earth composition is still O/Mg/Si/Fe?
>  Cayman Unterborn: (14:28) Well yes, but that doesn't say how much was accreted. That, to me, would give you an idea of how big your disk is and if that is even a reasonable size post planetary nebula
>  Alicia Aarnio: (14:33) @Cayman- iirc, this Zuckerman et a (& Jura) paper suggests 6e8g/s would be sufficient, a fraction of a planet's lithosphere http://adsabs.harvard.edu/abs/2011ApJ...739..101Z
>  Cayman Unterborn: (14:41) Thanks Alicia, I remember reading that paper. I just find it surprising we don't see more volatiles in these stars, but my intuition says all of the refractory stuff should have been blown away
>  Maggie Turnbull: (14:47) OR NEW WORLDS OBSERVER.  ;-)
>  Mike P: (14:47) :)
>  Mike P: (14:50) If you didn't see our promotional videos for the workshop, make sure to check them out on NAI's youtube page! Thank you all for coming to day 1 and come back tomorrow! http://www.youtube.com/playlist?list=UU14eJIZ7EWssOo9sBGp4d7Q
>  Mike Toillion: (14:50) The videos are awesome!
>  Anand Thirumalai: (14:51) Thank you Steve for putting my question to the audience. I would agree with you that we would not be able to say with certainty that Earth is made up of mostly O/Mg/Fe/Si, so perhaps the same applies to observations of several exoplanets.
>  Maggie Turnbull: (14:51) Mike, your videos are fantastic.  I'm really happy to see that, and I hope these types of videos become the standard for the prepping of future working groups.
>  Mike Toillion: (14:59) Thank you all!
>  Mike Toillion: (14:59) Please send any feedback to mike.toillion@nasa.gov
>  Elena Nickson: (15:00) Do you want feedback for the whole workshop or just each day individually?
>  Mike Toillion: (15:00) either/or : )
>  Mike Toillion: (15:01) Again, thank you all for participating!
>  Marco Boldt: (15:35) Survey is available at http://www.surveymonkey.com/s/www-stellar