News from the Society for Astronomical Sciences

News from the

Society for

Astronomical Sciences Vol. 12 No.3 (July, 2014)

Report on the SAS 2014 Symposium The 2014 Symposium was a “triple conjunction” joint meeting of the Socie- ty for Astronomical Sciences, the American Association of Variable Star Observers, and the Center for Back- yard Astrophysics. The Symposium featured educational workshops and presentations of (mostly) small- telescope research activities and results. The subjects spanned a re- markable range of targets and methods. Various presenters showed the fruits of their Photometry, CCD astrometry, spectroscopy, speckle interferometry and polarimetry (and spec- tro-polarimetry!). The targets being studied included asteroids, variable stars, binary star systems, superno- More than 170 people participated in the 2014 joint Symposium of the SAS, vae, classical novae, gamma-ray AAVSO and CBA. (Photo by Bob Stephens). bursts and urban light pollution. The Proceedings and videos of most of the technical paper presentations will be posted on the SAS website teroids that are – temporarily – cap- the “pro’s” with the opportunity to make “Publications” tab by the end of July. tured at one of Earth’s Lagrange detailed measurements on long- Meanwhile, here are a few topics that points. Such a “mini-Moon” could be a deceased supernovae. For example, particularly impressed and surprised candidate for a near-term, modest-cost Dr. Welch showed the spectrum of this reporter... robotic exploration mission. Watch for Tycho’s supernova (1572), measured more on this idea in the future. from its light echo. Dr. Lance Benner presented recent radar observations of near-Earth as- Eric Craine’s presentation of night- Another foray into unexpected territory teroids showing wonderfully detailed brightness measurements near Tuc- was described by Arto Oksanen, who three-dimensional pictures of these son illustrated the importance of gath- has succeeded in discovering – and objects speeding past us. It seems ering quantitative data, because light gathering photometry on – the optical that there are more “peanuts” and pollution is both complicated and in glows from gamma-ray bursts. This is “muffins” in the NEA population than I some ways counter-intuitive. Watch a very challenging project, to observe would have guessed. Dr. Benner also the video of his talk when it’s posted – very faint transient objects whose visi- noted the synergy between radar ob- you may be surprised! ble lifetime ranges from a few hours to a few days. servations, small-telescope astrometry Small-telescope research continues to (which provides accurate pointing for probe into unexpected territory. Two Supernovae showed up in several the radar), and small-telescope pho- such projects were described at the other discussions. Tim Puckett and tometry (which is used to determine Symposium: supernova light echoes, Dr. Michael Richmond presented an the asteroid’s rotation period and rota- and gamma-ray bursts. Dr. Doug educational workshop on “Supernova tional phase during the radar observa- Welch demonstrated that there are Discovery and Science”. The 70 partic- tions). probably quite a few still-undiscovered ipants in this learned about the need We were treated to an unplanned visit supernova light echoes in the Milky for more participants in Puckett’s ex- by Stephen Edberg (JPL), who de- Way, and that they can be found with traordinarily successful supernova scribed a challenge to search for as- diligent searches using amateur-scale discovery program, and received a telescopes. Once found, they provide “short course” on the various types of Society for Astronomical Sciences Newsletter Vol 12 Number 3 supernovae and their distinguishing Photometric Transforms (by Dr. Arne SAS Members are invited observational characteristics. Dr. John Henden). Martin presented a discussion of su- to Participate in AAVSO’s pernova lightcurves, the challenge of Equipment problems prevented us Fall meeting distinguishing between “real” superno- from recording the Supernova work- November 6-7-8, 2014, (Woburn, vae and transient sources that are shop and Arne’s “Transforms” class MA) actually “imposters”, and the signifi- (which is a shame, because they were both really good). cance of small-telescope and amateur contributions to his research. Finally, Videos of Tom’s Spectrum Processing during an informal lunchtime “spec- class and Bob’s Signal-to-Noise Ratio The AAVSO’s Fall meeting will be a troscopy discussion group” (of about class are both freely available on the joint AAVSO-SAS gathering. It will be 40 people) it was pointed out that SAS website. held on November 6-7-8 in Woburn backyard-scale telescopes can be MA. All SAS members can attend at effectively used for supernova confir- The following workshop videos from the AAVSO member registration rate. mation. past years are also available: If you would like to present a paper at this meeting, you should submit an The annual SAS Symposium is a Digital Imaging Photometry (2013) abstract using the normal AAVSO pro- unique opportunity to experience the Lightning Safety and Hazard Man- cess: details will be announced on the breadth and depth of small-telescope agement (2013) AAVSO website in August. Accepted astronomical research. I imagine that presentations will be assigned to an all of the participants enjoyed connect- Small-Telescope Spectroscopy (2012) oral or poster presentation as needed. ing with old friends and meeting new Robotic and Remote Observatories AAVSO doesn’t publish Proceedings ones, while collecting a list of projects (2011) for the meeting, but you can submit to try during the coming year. The your paper to the JAAVSO, and it will sponsors and vendors were well- Eclipsing Binary Stars (2011) be treated like any normal paper with a prepared to provide everyone with any reviewer. SAS members will be given If you’d like DVDs of these prior-year new gear that those projects may de- free page charges in the Journal for workshops, send a note to Bob Buch- mand. papers derived from this meeting. heim ([email protected]). If you The Program Committee will soon be were registered for the workshop when As part of this gathering, SAS is plan- discussing plans for the 2015 Sympo- it was held, the DVD cost is $5. Oth- ning to host a workshop on “Superno- sium. We appreciate the input from erwise, the cost is $55. va Confirmation with Slitless Spectros- those of you who filled in the “2014 copy”. Survey” at the Symposium; if you for- got to turn your survey in, or if you’ve This topic flowed out of thought of additional comments, two subjects that were please send a note to Dale Mais, who presented at the SAS- is collating the survey responses. 2014 Symposium. Tim Puckett noted during his If you weren’t able to attend the 2014 Supernova workshop that Symposium, some of the features of quite a few probable- the Symposium are available to you. supernova discoveries are The Proceedings document will soon never confirmed by spec- be available on the SAS website; and troscopy, and hence they videos of most of the technical presen- never get a “supernova” tations will also be available for view- designation. Dr. John ing, with links on the SAS website Martin described several “Publications” tab. As in past years, types of “supernova im- both the Proceedings and the videos posters” that can show up are made freely available as a service on the lists of transient to the small-telescope research com- discoveries. munity. A great many of these uncharacterized discoveries appear to be within range of backyard-scale Workshop Videos telescopes using low-cost slitless spectrographs. The SAS-2014 Symposium featured a This provides an interest- half-day workshop on Supernova Dis- ing way to apply amateur covery and Science (presented by Tim spectroscopy to a scientif- Puckett and Dr. Michael Richmond), Dr. Linda French discussed her research on Jupiter ically-useful project, with- plus three short classes on Spectrum Trojan asteroids. (Photo by Bob Stephens) out making a large in- Processing (by Tom Field), Signal-to- vestment in equipment or Noise Ratio (by Bob Buchheim) and training.

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Lowell Observatory Pro- Help Requested for 2014 um are available in PDF format at the PUBLICATIONS tab of the SAS website Am Workshop on Speckle “Science Imaging & As- (www.SocAstroSci.org). Interferometry tronomy” Event Symposium Videos: If you missed a Friday-Sunday, October 3-5, 2014, October 11th, Pierce College, Wood- recent Symposium, you can still watch Giclas Lecture Hall, Lowell Observa- land Hills, CA the presentations. Videos of most of tory (Flagstaff, AZ) the technical presentations have been Our Sponsor Woodland Hills Tele- posted on the SAS website at the This isn’t an SAS-sponsored event, but scope & Camera organizes the annual PUBLICATIONS tab. it will be of interest to those of you “Science Imaging and Astronomy” who were you intrigued by the “speckle event. The particular focus of SIA is Contact Information: If you haven’t interferometry” talks at SAS 2014. The reaching out to young adults, in hopes been receiving e-mail messages about workshop will include one night of ob- of getting them infected with the “as- the Newsletter or the SAS Symposium, serving on the Discovery Channel Tel- tronomy bug”. Farah Payan has asked perhaps it’s because you’ve changed escope, and will offer hands-on expe- if any SAS members would like to or- your e-mail address. You can update rience with data reduction of speckle ganize a telescope and camera clinic, your contact information on the images. or give a talk during the SIA-2014. If MEMBERSHIP/REGISTRATION tab of the you are interested in helping out, SAS website. SAS never sells or Speckle interferometry, once the sole shares your name or contact infor- province of professional astronomers, please contact Woodland Hills Tele- scope & Camera at 888-427-8766. mation without your explicit permis- has expanded to include many ama- sion. teur and undergraduate and even high school student observers and analysts. This expansion is due to the increased availability of high-speed CCD camer- Reminders ... Publication of Student Pro- as, powerful PCs, PC-friendly soft- jects and Research Papers ware, and opportunities for publication. Membership Renewal: Even if you can’t attend the annual Symposium, Recent SAS Symposia have included Speckle interferometry overcomes we value your support of the Society student groups who described their normal atmospheric seeing conditions for Astronomical Sciences, and your projects on asteroid lightcurves; stellar by taking a series (often thousands) of interest in small-telescope science. spectroscopy; double-star astrometry; short-exposure images (typically 10-60 You can renew your membership on and sky-glow evaluations. In keeping milli-seconds) which “freeze out” the the SAS website (SocAstroSci.org), by with the SAS mission of encouraging usual atmospheric smearing. Speckle going to the MEMBERSHIP/REGISTRATION small-telescope astronomical re- interferometry only works within the tab. search, we applaud these efforts. isoplanatic patch where atmospheric distortions are correlated – typically Symposium Proceedings: Published SAS will now offer a forum ensuring less than 10 arc seconds. Analyzing proceedings from the 2013 Symposi- that similar work will be part of the speckle images works best when observing geometrically simple objects such as close visual double stars and binary asteroids. The Lowell Speckle Interferometry Workshop will bring professional, amateur, and student astronomers together in a synergistic mix that aims to con- sider science programs, speckle observations, data reduction, and analysis in a hands-on, informal atmosphere. The workshop will feature a speckle interferometry observation session on Lowell Observatory’s 4.3-meter Dis- covery Channel Telescope in nearby Happy Jack. This session will use the Differential Speckle Survey Instrument (DSSI) developed by Dr. Elliott Horch. DSSI features simultaneous observations in two color bands and two Andor iXon EMCCD cameras. (This activity is “weather permitting”, of course). Dr. Michael Richmond rolled up his sleeves and taught about supernovae – as part of a formal workshop, and during an informal discussion group. (Photo by Hans Registration information will be availa- Strupat) ble in the near future.

3 Society for Astronomical Sciences Newsletter Vol 12 Number 3 astronomical literature, and that stu- Symposia: a Yahoo Group called dents can include a publication citation SocAstroSci has been set up as a fo- in their resumes, even if they are not rum for discussion of any topic related V401 Cyg: Possible Ter- able to attend the Symposium. to SAS and small-telescope astronomical research. Kevin Hearst volun- tiary Eclipse We will be pleased to receive student- teered to be the moderator of the In the October, 2013 edition of this research paper submissions for the group. (Thanks, Kevin!). SAS Newsletter. The papers will be Newsletter, we presented a summary considered as “pre-prints”, so that they You can reach the group at of “Properties of the Close-In Tertiary are made available promptly. They will https://groups.yahoo.com/neo/groups/ in the Quadruple Sys-tem V401 Cyg” be formally published as “papers with- SocAstroSci/, or by searching the Ya- by L.-Y. Zhu, et al in AJ (46:28, 2013 out presentation” in the next SAS Pro- hoo Groups page for SocAstroSci. August) ceedings volume. Check it out and see what’s happen- V401 Cyg is an eclipsing contact- ing. Please encourage your students to binary, with a deep primary eclipse submit appropriate papers by e-mail to A Classroom Spectrograph You Can (ΔR ≈0.5 mag). The O-C (observed- a Newsletter Editor. Borrow minus-calculated) analysis of eclipse times shows a pretty clear cyclic pat- Jeff Hopkins donated to SAS a “REX tern, which is attributed to the light- Spectrograph”, which is a neat piece of time effect caused by a tertiary star in Keeping in Touch ... classroom equipment to demonstrate an approximately 3.5 year orbit around spectroscopy. Several participants at Announcing an SAS Yahoo Group the eclipsing pair. The presence of the the SAS-2014 wanted to borrow it, so “SocAstroSci” tertiary star has also been inferred by it’s currently out on loan. We’ll get a other photometric studies and by spec- The SAS Symposium is a premier fo- case for it that will (hopefully) let it sur- troscopic observations, so its presence rum for small-telescope researchers to vive shipping to and from borrowers. If is pretty certain. (There is also a visu- discuss ideas, observing procedures, you’d like to be added to the interest al-double companion about 18 arc-sec and equipment insights; to share pro- list, send a note to Bob Buchheim away that presumably is part of this ject results; and to form collaborations. ([email protected]). We’ll prob- system, but doesn’t play any role in the Since our membership is scattered ably create a sign-up list on the So- eclipses or the light-time effect.) across the United States and around cAstroSci Yahoo Group in the near the world, we’re trying an experiment future. to help people keep in touch between

Where did the SAS-2014 attendees come from? Here are markers showing the US zip codes and countries from which regis- trations were received. Thanks to Bob Stephens for compiling this map.

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Zhu et al used the O-C data to esti- tertiary eclipse timing exactly, but they a worth-while addition to your project mate the orbit of the tertiary star; their expect it to happen sometime between calendar, if you’re a fan of eclipsing result suggests that it might eclipse the mid-October and mid-November, binaries. V401 Cyg is Vmag≈11, and contact pair. The lightcurve of such an 2014. Of course, Cygnus is pretty low is located at (J2000) RA=19h 29m eclipse would offer some valuable data in the west by then, so you’ll only have 19.5s Dec: +30°24'11". about this hierarchical triple system. a few hours each night to make time- Their orbit solution can’t pin down the series photometry, but this sounds like

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Technical Report A detailed review by this author has been conducted of De- genhardt's multiple papers and website as well as a direct Review of Claims for Dense Io Atmos- review of copies of his original data for four events (which he phere provided), plus extensive communication with him. This review led to the conclusions discussed below. by John Menke [email protected] The conclusion of the review is that there are multiple reasons (in addition to Mallama's list) for concluding that the May 26, 2014 interpretation of the observations as showing an atmosphere on Io is incorrect. Abstract: A detailed review has been performed of the evi- 1. Saturation. Inspection of the video data showed that dence supporting claims that a thick atmosphere exists on as occultation approached, the images of Io and Europa the Jupiter moon Io. This has allegedly been detected by its coalesced or began adding together (see drawing). As the dimming effect during occultations of Europa behind Io. This images merged (before the occultation), saturation of pixels review showed that this conclusion is in error. The error (i.e., values=255) became extensive in the Io/Europa imag- arose from incorrect use of the video camera observation es, but was not present at other times nor for other targets. method resulting in extensive sensor saturation (over load- In performing a photometric measurement in which accurate ing) during the event. The saturation led to reduced appar- intensity measurements are the goal, any significant satura- ent brightness which was incorrectly interpreted as dimming tion or even near approach to saturation (Roll-off), puts the from an atmosphere. Also noted is that both eclipses and quality of the results in serious question. Saturation inevita- occultations should show the effect; however, they do not. bly causes data to be lost, i.e., light not to be measured, and hence, apparent dimming (which will show as "wings" in the light curve). Note that the saturation observed is in the original data – the presence of saturation is not a derived or in- Discussion: Degenhardt in SAS2010 and in other references has used video to observe the occultations of one Jupiter moon (Io) on another (Europa). He observed 15-30 minutes of apparent dimming before and after the actual occultation which he ascribed to the shadow of an Io (front) atmosphere (radius approximately 10 x Io R.) falling on Eu- ropa (rear). He calls these Jovian Extinction Events (JEE), and refers to the dimming as "wings" on the light curve of the occultation event.

ferred result. To evaluate whether saturation could be proved as the cause of the observed dimming/wings, a computer model simulating coalescing stellar images showed that saturation/Roll-off would in fact consistently produce the observed "wings". In another line of research on the data, unsaturated images of Ganymede from the very same video were used as a surrogate for Io/Europa. When saturation was simulat- ed (using software) to the Ganymede images, the result was the same dimming as in the Io/Europa data. This confirms that the observed saturation caused the observed wings/dimming. 2. Negative Results. During some occultation events, some observers do not see "wings" while others do observe wings. I examined two of these "negative" video files, and However, an atmosphere of the density needed to cast such found that the observer had used a longer focal length tele- a shadow has never been observed by astronomers either scope that produced larger (more pixels), less intense Io and from the earth or from the multiple space probes. In his Europa images, and hence had no saturation, and no dim- 2013 paper reviewing the JEE claims, Mallama has conclud- ming. That is, the light curves are as one would expect. In ed that it is impossible that the various studies over 200 addition, there are also other observations of some of the years could have missed this atmosphere, particularly be- same events by other observers using video cameras but do cause searches for atmosphere have been repeatedly made not show dimming or "wings" in the light curves. with increasingly sophisticated measurements. He con- cludes that the JEE wing claims are incorrect.

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occultation, the rear satellite passes behind the front (seen from earth), so the two satellite images in our telescope coalesce, causing the peak pixel readings to rise to saturation levels (in the setup used by most of the JEE observers), thus reducing the apparent total intensity and forming the JEE wings.. Observing wings with occultations but not with eclipses is a fundamental contradiction in the JEE “extended atmosphere” interpretation. Conclusion. There are compelling astronomical reasons to question the JEE atmosphere interpretation. These include the wide range of professional research on Jovian moons that has found only traces of an atmosphere around Io, and the fact that eclipses and occultations should both show the same effect--which they do not. There are also instrumental problems: The recorded data show extensive saturation, indicating that the observing in- 3. Eclipses. An eclipse, by definition, has the rear sat- struments were not used properly. Three different lines of ellite passing through the shadow of the front satellite itself analysis show that the observed saturation was sufficient to and any shadow cast by a front satellite atmosphere. In have caused the wings. contrast, when one (front) satellite occults the another (rear) satellite, the rear satellite can actually miss passing through To quote Carl Sagan "Extraordinary claims require extraor- the shadow at all, or may pass though only part of the shad- dinary evidence" That test is not met here. ow. However, during the occultation, we do see the rear satellite through any such front satellite atmosphere, which would produce the same dimming as the atmosphere shad- References ow cast during an eclipse. In general, both eclipses and SAS2010. Proceedings of the 2010 Society for Astronomical occultations should show very similar dimming/wings, if a Sciences. http://www.socastrosci.org/publications.html thick atmosphere exists. In his very first paper SAS2010, Degenhardt shows a light curve of an Io/Europa eclipse fol- SAS2013. Proceedings of the 2013 Society for Astronomical lowed 20 minutes later by an Io/Europa occultation. The Sciences. http://www.socastrosci.org/publications.html eclipse shows no wings, while the occultation does. In fact, no eclipses show wings. Degenhardt website. This site contains many supporting documents and papers concerning the JEE work. See Why does the occultation show dimming/wings and the http://scottysmightymini.com/JEE/ eclipse not? During the eclipse, the two satellite images are not in our line of sight, so they remain separated on the vid- Mallama. "The Atmospheres of Io and Europa Are Trans- eo detector, i.e., the images do not coalesce, and pixel val- parent" JALPO 55-4 ues remain relatively low. However, during the run-up to an Editors note: It is critical to strive for high-quality photometry, free of artifacts, during the upcoming 2014-2015 Jupiter observing season.

Small-Telescope Astronomical Science in use a faint comp star in the field. That’s a problem for (at least) two reasons: the low-SNR comp star will imply poor the News: April-June 2014 photometric accuracy; and the short exposure may aggra- compiled by Bob Buchheim vate the reduction of photometric accuracy due to atmospheric scintillation. You could use a wide-field imager to Well, I got too busy this quarter, so I didn’t make my usual capture the target and a comparable-brightness comp star in overview of the literature for small-telescope science results. a single (wide) field, but the wide field presents the risk of I did run across the following paper that might interest some incomplete compensation for atmospheric extinction. Or you SAS photometrists. can try the technique reported in this article: place a wire mesh in front of the telescope aperture. The mesh is, in effect, a two-dimensional grating, so each star is trans- CCD photometry of bright stars using objective wire formed into a series of diffracted images. The brightness mesh ratio between the Nth diffracted order and the 0th order is by Krzysztof Kaminski, et al constant (assuming a perfect grating). The authors use this arXiv:1404.3440v1 (accepted to AJ) to increase the effective dynamic range of their differential photometry. They use the 1st (or 2nd) order image of the Say that you need to do photometry on a bright star, and target, and the zero-order image of the comp star to achieve there is no comp star of comparable brightness nearby. You excellent differential photometry accuracy (± 0.02 to ± 0.004 could try using a short exposure (to avoid saturation), and

7 Society for Astronomical Sciences Newsletter Vol 12 Number 3 mag), with a 3-mag target and a 9th mag comp star. The seismology radial-velocity studies. There are several types effective brightness of the target is reduced (by the diffrac- of imperfections in the “objective mesh” that can alter the tion efficiency of the 1st or 2nd order), so relatively long expo- diffraction efficiency of different orders, but the authors (ad- sures (a few minutes) can be used, eliminating “atmospheric mittedly limited) studies indicate that these aren’t an imped- scintillation” noise. iment to excellent photometry. It is probably best to try your own experiments, but this is an interesting resurrection of an This idea may be fruitful for bright-star photometry projects. idea that saw service in the late 19th century (using photo- The authors particularly mention the need to have high- graphic plates). accuracy photometric monitoring to supplement stellar-

SAS Leadership Membership Information SAS Contact Information The Society for Astronomical Sciences 9302 Pittsburgh Avenue, Suite 200, Corporate Officers: welcomes everyone interested in small Rancho Cucamonga, CA 91730 Bob Buchheim – President telescope astronomical research. Our Lee Snyder – President Emeritus mission is to provide education, foster Robert Stephens: Robert Stephens – Treasurer amateurs’ participation in research [email protected] Robert Gill – Secretary projects as an aspect of their astronomical hobby, facilitate professional- Newsletter Editors: Newsletter Editors: amateur collaborations, and dissemi- Dale Mais: Dale Mais nate new results and methods. The [email protected] Robert Buchheim Membership fee is $25.00 per year. Bob Buchheim: [email protected] Program Committee: As a member, you receive: Jerry Foote • Discounted registration fee for the On the web: [email protected] annual Symposium. www.SocAstroSci.org • A copy of the published proceedings Registration: each year, even if you do not attend Margaret Miller the Symposium. Cindy Foote Membership application is available at All SAS Leaders are volunteers, serv- the REGISTRATION page of the SAS ing without compensation. web site: http://www.SocAstroSci.org.

Advisors: The SAS is a 501(c)(3) non-profit edu- Dr. Arne Henden cational organization. Your Member- Dr. Alan W. Harris ship dues and donations may be tax Dr. Dirk Terrell deductible.