May 16, 2014 Mary Gates Hall

Stellar Magnetic Activity and Planet Parking: SESSION 2G Limitations on Planetary Migration Megan Lindsay (Megan) Brehm, Fifth Year, Astronomy, Physics: Comprehensive Physics ASTRONOMYAND LHCPHYSICS Mentor: Sarah Ballard, Astronomy Session Moderator: Suzanne Hawley, Astronomy 248 MGH We want to understand whether or not the underlying mag- 3:30 PM to 5:00 PM netic activity of a star plays a role in the ”parking” of a planet * Note: Titles in order of presentation. as it migrates inward. Magnetic activity of a planet’s host star is one among a bevy of factors that inform planetary mi- Carbon-IV Based Supermassive Blackhole Mass gration, and may imprint itself on the final orbital location Estimators and Emission Variability in High Redshift of a planet. In this framework, less active stars allow planets Quasars to reside nearer to them than their more active counterparts, Ramon Sudarshan (Ray) Sharma, Senior, Astronomy, which ”brake” planets’ inward migration sooner. NASA’s Ke- Physics: Comprehensive Physics, Mathematics pler mission collected an ideal data set to address this ques- Undergraduate Research Conference Travel Awardee tion. It detected thousands of extrasolar planets from the pe- Mentor: John Ruan, Astronomy riodic dimming of their host stars as the planet crossed the Mentor: Eric Agol, Astronomy face of the star. By using the data collected from the mission, we are initially attempting to find a relationship between the The Carbon IV emission line in quasar spectra is well-known mass of the host star and the current location of its nearest to show systematic shifting toward smaller wavelengths of- planet. We employ stellar mass as a proxy for stellar activ- ten attributed winds flowing off the accretion discs along the ity for this preliminary treatment. We can infer some level of line of sight. We investigate variability in the shift of the C stellar activity from the mass of the star, but we plan further IV line in two ways, using spectra observed multiple times: investigation to determine the extent of this relationship and through correlation of the shift with changes in the intensity how it may change over time. We will look at the brightness of the rest of the quasar, as well as through the effects of this variations of the stars in the Kepler sample, over short and variability on host supermassive black hole mass estimates. long timescales, in order to infer stellar activity in a more ro- Our results show weak to no correlation between changes in bust fashion. Then, we will jointly examine where the closest the shift with quasar light flux between observations, poten- orbiting planet resides around this sample of stars. We will tially indicating near-constant outflow speeds. We addition- establish how this parking distance relates to stellar type and ally investigate biases in existing SMBH mass estimates by stellar activity. We aim to untangle the role of magnetic activ- comparing our multiple-observation estimated masses with ity from the other factors determining planetary architecture. masses derived from single observations. Our results indi- cate that the previously observed correlation between C IV shift and SMBH mass can be empirically corrected thanks to POSTER SESSION 3 the lack of variability in C IV shifts, leading to less biased MGH 241, Easel 156 SMBH masses. This will help pave the way for much more 2:30 PM to 4:00 PM accurate methods of calculating masses for extremely distant black holes, and helps constrain physical structure models of Detection of Transiting Exoplanets using Kepler active galaxies. Lightcurves John Mark (John) Mehlhaff, Senior, Computer Science, Physics: Comprehensive Physics POSTER SESSION 3 NASA Space Grant Scholar MGH 241, Easel 159 Mentor: Eric Agol, Astronomy 2:30 PM to 4:00 PM Mentor: Andrew Becker, Astronomy Exoplanets are planets outside our solar system. The discov-

Undergraduate Research Program 1 exp.washington.edu/urp ery and characterization of exoplanet systems informs us of data, it is possible to deduce the presence of Trojan asteroids the types of worlds found in nature and whether they might and their properties. However, if we are unable to detect these support life. There have been an unprecedented number of Trojan asteroids, we will be able to set limiting constraints exoplanet detections in recent years spurred in large part by on the presence of asteroids in exoplanetary systems. Obser- the advanced observing capabilities of NASA’s Kepler Space vations of these Trojan asteroids, or the lack thereof, would Telescope. The Kepler Spacecraft continuously monitors a give insight to the evolution and migration models of these large, fixed set of stars and collects time series photomet- systems. These results will ultimately lead to a better under- ric data that are unparalleled in both quantity and precision. standing on how planetary systems form, through which pro- Plots of stellar brightness against time called lightcurves are cesses they migrate, and how they compare to our own solar the canonical representation of Kepler data. The goal of our system. research is to detect exoplanets from the characteristic fea- tures they produce in these lightcurves known as transits. A transit occurs when an orbiting planet partially eclipses its POSTER SESSION 3 stellar host, reducing the brightness observed by the tele- MGH 241, Easel 163 scope and recorded in the lightcurve. To detect transits, 2:30 PM to 4:00 PM we use the Quasi-Periodic Automated Transit Search Algo- rithm (QATS). As an automated tool, QATS is instrumental Automated Classification of Variable Stars for LSST via in reducing the effective size of the Kepler dataset. How- Machine Learning ever, QATS is sensitive to variability of the target star and Christopher James Martin, Senior, Astronomy, Physics to systematic artifacts of the telescope just as it is to transits. Mentor: Zeljko Ivezic, Astronomy Thus optimal detection efficiency requires removal of all non- The Large Synoptic Survey Telescope (LSST) will carry out transit signals prior to applying the algorithm. Determining an unprecedented imaging survey of half the sky. With about the best way to do this is the present focus of our work be- 1000 observations over a 10-year period, these data will en- cause it bounds our ability to detect planets whose size, com- able faint time-domain astronomy. The measured properties position, and orbital parameters are conducive to life. of newly discovered and known astrometric and photometric transients will be publicly reported within 60 sec. Several POSTER SESSION 3 hundred million variable objects will be detected and due to this large number their fast classification, that is a prerequisite MGH 241, Easel 158 for timely follow up with other facilities, will have to be un- 2:30 PM to 4:00 PM dertaken using machine learning methods. Before selecting a In Search of Trojan Asteroids in Exoplanetary Systems subset of the most interesting variable objects for follow up David Douglas (David) Bordenave, Sophomore, Physics: observations, known types of variable stars, which will dom- Comprehensive Physics, Astronomy inate the sample, will have to be efficiently recognized and Mentor: Sarah Ballard, Astronomy classified. This project assesses the extent to which machine learning methods are able to recognize known classes of vari- “Trojan” asteroids, or asteroids trapped in stable gravitational able stars, and how this performance scales with the number positions preceding and trailing a planet in its orbit, accom- of data points. A sample of 7,000 variable stars, manually pany almost every planet of our solar system. These hunks of classified by domain experts, served as our training sample. rock were captured into their current locations in the early This dataset, collected by the LINEAR survey, contains all stages of our solar system’s formation, and their presence the major types of variable stars and has sufficiently precise hints at the dynamical history of bodies orbiting the Sun. and well-sampled observations for a detailed light curve anal- However, we have no reason to assume that our own planets ysis. Fourier series expansions allowed us to quantify these are alone in possessing Trojan asteroids. The Kepler Space light curves, and asses various classification methods in the Telescope mission, launched in 2009, has been instrumental subsequent best-fit Fourier coefficient space. We explored in the recent search for exoplanets (planets orbiting stars other this space using Support Vector Machines, K-nearest neigh- than the Sun). It identifies these planets from a tell-tale dip in bor classifier and decision tree methods, and compared the starlight when a planet passes in front of its host star. It has performance of these methods via their Receiver Operating identified thousands of new worlds to date. However, no stud- Characteristic curves. ies have yet been made attempting to detect Trojan asteroids accompanying these exoplanets from the Kepler photometry data. We expect to be able to detect these asteroids using POSTER SESSION 3 statistical model fitting to the Kepler data, similarly to how MGH 241, Easel 166 exoplanets themselves are detected. By fitting a model based 2:30 PM to 4:00 PM on the properties of the particular exoplanet to the photometry

2 Exploring the Relationship between Neutral Chlorine icantly smaller than our sun. Despite their diminutive stature, and Molecular Hydrogen in Interstellar Gas Clouds they are also the common stars in the universe, and the hard- Jennifer Ashley (Jenn) Hobbs, Freshman, Latin est to characterize. We understand the planets orbiting these Mentor: Adam Ritchey, Department of Astronomy stars only as a well as we understand the stars themselves. Molecular hydrogen is an important component of star and To this end, for our project we seek to refine our knowledge galaxy formation, but, unfortunately, is difficult to observe of the temperatures and radii of a select group of M dwarf Kepler and measure directly. Neutral chlorine, however, is easier to host stars of interesting exoplanets identified with the Space Telescope detect and can be used to trace molecular hydrogen, because . We employ dozens of near-infrared spectra ionized chlorine rapidly reacts with molecular hydrogen and gathered at the 3.5 meter telescope at Apache Point Obser- becomes neutral. While it is well established that there is a re- vatory in New Mexico to study these planet hosts. We will lationship between neutral chlorine and molecular hydrogen, leverage features in the near-infrared portion of these stars’ there has been little research done using modern observations spectra to understand their physical properties. The radius to determine the specifics of this relationship and to apply it and temperature of the star will then tell us more about the to distant absorption systems. By comparing the amounts of possibly terrestrial planets they are hosting, and whether they molecular hydrogen and neutral chlorine (as well as atomic reside in their stars’ habitable zones. hydrogen and ionized chlorine) along the sightlines of vari- ous stars in the Milky Way, we hope to produce a more ac- POSTER SESSION 3 curate chemical model of the interstellar clouds that contain MGH 241, Easel 165 these gases and to improve on the method for using chlorine 2:30 PM to 4:00 PM to determine the molecular content of distant galaxies. At this stage in our research, we have discovered that the fraction of Deriving the Metallicity of a Selection of Little-Studied hydrogen in molecular form in the dense cores of these inter- Open Clusters stellar gas clouds is significantly larger than the ratio used in Anthony Matthew (Anthony) Paat, Senior, Astronomy, current chemical models. Also, while previous research has Physics found that the slope of the correlation between neutral chlo- UW Honors Program rine and molecular hydrogen is near one, our research, which Nancy Helen (Nancy) Thomas, Senior, Astronomy, Physics includes a wider variety of sight lines, is revealing that this Mary Gates Scholar, NASA Space Grant Scholar, slope is actually significantly smaller. As we continue with Undergraduate Research Conference Travel Awardee, UW our research, our next goal will be to repeat the process we Honors Program have used on Milky Way stars on stars in the Large and Small Denise Marie (Denise) Schmitz, Senior, Mathematics Magellanic Clouds and to see if our findings close to home (Comprehensive), Physics: Comprehensive Physics, hold true as we move farther away. Astronomy Mary Gates Scholar, Undergraduate Research OSTER ESSION Conference Travel Awardee, UW Honors Program P S 3 Ramon Sudarshan (Ray) Sharma, Senior, Astronomy, MGH 241, Easel 160 Physics: Comprehensive Physics, Mathematics 2:30 PM to 4:00 PM Undergraduate Research Conference Travel Awardee Mentor: Ana Larson, Astronomy The Little Guy Pulls Ahead: Understanding M Dwarfs and their Planets Previously, details on the angular diameter, age, reddening, Jessica Anne (Jessi) Shank, Senior, Astronomy, Physics: and distance from the sun have been published for 60 open Comprehensive Physics star clusters. This previous research mentioned the metallic- Mentor: Sarah Ballard, Astronomy ity of these clusters, but no results were published with metal- licity values. According to the Big Bang theory, the early Until the launch of NASA’s Kepler mission in 2009, the exis- universe contained mainly Hydrogen with small amounts of tence of rocky, Earth-like planets orbiting stars other than our Helium. For heavier elements to form, fusion inside a stel- Sun was uncertain. In the 5 years since its launch, the mission lar core must take place. When these stars die they then identified a wellspring of thousands of planets. We now know expel heavier elements, called ‘metals’ by astronomers, into that planets around other stars are the rule, rather than the ex- space. These metals will then be present for the next genera- ception. One of the most interesting and surprising discover- tion of stars that forms. Therefore, if astronomers can derive ies emergent from Kepler is that planets are not most common the metallicity of a star they can figure out the relative age around Sun-like stars. Rather, they reside most often around of that star. The University of Washington League of As- small stars known as M dwarfs. These stars are cool, with tronomers club research group wrote a proposal to observe effective stellar temperatures of 2000-4000 K, and are signif- at the Dominion Astrophysical Observatory (DAO) in Victo-

3 ria, Canada and received eight nights of time on DAO’s 1.8 Testing Stellar Evolution in M31 via the Hubble Space m telescope. We have obtained images of many of the target Telescope clusters using Stromgren¨ filters. Observations using these fil- Peter Edward (Peter) Senchyna, Senior, Physics: ters will allow us to calculate the metallicity of stars within Comprehensive Physics, Astronomy each of our target clusters. Ultimately, by determining the Mary Gates Scholar, NASA Space Grant Scholar, UW metallicity of a range of open star clusters within the plane of Honors Program the Milky Way, we can help constrain the galaxy’s metallic- Mentor: Julianne Dalcanton, Astronomy ity gradient which gives us a better understanding of galactic Mentor: Cliff Johnson, Astronomy formation and chemical evolution models. Mentor: Morgan Fouesneau, Astronomy Our understanding of our own galaxy and those at great dis- POSTER SESSION 3 tances hinges on how well we can model the complex pro- cesses by which stars form and evolve. The best laborato- MGH 241, Easel 157 ries in which to test our predictions are star clusters - groups 2:30 PM to 4:00 PM of stars which by assumption formed at the same time. The Spectroastrometric Detection of Exomoons nearby Andromeda galaxy (M31) is a fantastic source of clus- Tiffany Channelle (Tiffany) Jansen, Junior, Astronomy, ters with similar chemical properties to our galaxy, at a va- Physics: Comprehensive Physics riety of ages, and close enough to be resolved into individ- Brianna Irene (Brianna) Lacy, Junior, Astronomy, Physics: ual bright stars by space telescopes. However, distinguish- Comprehensive Physics ing cluster members from other field stars is a difficult prob- Mentor: Eric Agol, Astronomy lem. We have developed a method to assign a cluster mem- Mentor: Tyler Robinson, Astronomy Department, NASA bership probability to a given star by comparison with the Ames Research Center density profile and properties of the cluster. We apply this method to a sample of well-characterized clusters observed At typical interstellar distances, the separation between a by the Panchromatic Hubble Andromeda Treasury (PHAT) moon and its planet is too small to resolve; the separate spec- program, which has provided Hubble-based photometry of tra of the two objects combine and appear like one object. At unprecedented depth in the M31 disk. As a first applica- most wavelengths the planet will outshine its moon, heavily tion, we study a subset of clusters associated with evolved skewing the center of light towards the planet. However at stars that are known to be Cepheid variables - a class of pul- certain wavelengths a moon may outshine its planet, skew- sating supergiant star to which stellar models can provide a ing that center of light towards the moon instead. Spectro- precise age. We demonstrate the accuracy of the method and astrometric methods would find exomoons by detecting a characterize this newly identified population of M31 cluster shift in the center of light at a moon-dominated wavelength Cepheids. We extend this method to the entire PHAT clus- versus a planet-dominated wavelength. Once a moon is de- ter sample, seeking to establish cluster membership of bright tected, tracking the motion of the center of light would also supergiant, horizontal branch, and AGB stars therein. The un- provide information about the masses and separation of the precedented size and quality of this sample of M31 clusters moon and planet. This research project is examining two sys- will allow us to test existing models of these important stages tems: the Moon around the Earth, and an Earth-like moon of stellar evolution. around a warm Jupiter. Modeled spectra of the three objects were then used to model the detection of the two types of systems at a distance of 10 parsecs. For the Earth-Moon sys- POSTER SESSION 3 tem, the strongest Moon dominated wavelength was found to MGH 241, Easel 169 be 2.83 microns. For the Jovian-Earth system, the strongest 2:30 PM to 4:00 PM Earth dominated wavelength was found to be 2.44 microns. Further work will explore the signal to noise ratios and thus Bulge Kinematics of Giant Low Surface Brightness determine how large of a telescope is necessary to feasibly Galaxies use this technique in the future. Denise Marie (Denise) Schmitz, Senior, Mathematics (Comprehensive), Physics: Comprehensive Physics, Astronomy POSTER SESSION 3 Mary Gates Scholar, UW Honors Program, MGH 241, Easel 161 Undergraduate Research Conference Travel Awardee 2:30 PM to 4:00 PM Mentor: Peter Yoachim, Astronomy Giant low surface brightness galaxies (GLSB) are a class of spiral galaxies with larger and fainter disks than typical spi- rals. Previous theoretical work suggests that their formation

4 history is distinct from that of normal spiral galaxies. Two main theoretical models for GLSB formation have been pro- posed. One possibility is that they begin as ordinary spirals and undergo a face-on impact with a small satellite, creating a compression wave (i.e., a collisional ring) which excites star formation throughout the neutral hydrogen disk and results in a large, faint stellar disk. A competing possibility is that GLSBs begin as elliptical galaxies or normal spirals and ac- quire disks through tidal disruption and accretion of a satellite galaxy. Preliminary investigation of these objects has shown that they possess bulges which are morphologically and pho- tometrically similar to typical elliptical galaxies, suggesting that the GLSB disks could be the remnants of a satellite ac- cretion event. Using the Apache Point Observatory, we have obtained longslit spectra of the central bulges of two GLSBs, Malin 2 and UGC 6614. Combining these data with spatially resolved spectra of the disks taken at the McDonald Observa- tory allows us to compare the disk and bulge kinematics and distinguish between the possible formation scenarios. Our analysis reveals that disk and bulge kinematics are closely correlated in both targets, which is consistent with both pos- sibilities but may favor the collisional ring galaxy scenario.

POSTER SESSION 4 MGH 241, Easel 163 4:00 PM to 6:00 PM

Searching for M-Dwarf Flares using Kepler Tessa D. (Tessa) Wilkinson, Junior, Astronomy, Physics: Comprehensive Physics Mentor: James Davenport, Physics & Astronomy, Western Washington University Mentor: Suzanne Hawley, Astronomy

M dwarfs are small stars with masses between 10 and 50% that of the Sun. They are also the most common, making up about 70% of the stars in our galaxy, and are noted for their high levels of magnetic activity. Stellar flares are a dra- matic manifestation of this activity, and occur frequently on M dwarfs. Flares are explosive events resulting from rear- ranging magnetic fields on the stellar surface. We used data from the Kepler satellite to search for flares from a binary M dwarf system, named GJ 1245. With more than 8 months of continuous imaging, taken every 1-minute, we detected over 3,000 flare events from these twin stars. We conducted a by- eye search of this data to validate our automatic flare-finding code. We present the energy distribution and morphology for flares on these stars, and compare them to other well studied flare stars from Kepler. The long term goal is to train the au- tomatic flare-finding code to run without the need for human validation, and thus to study tens of thousands of stars. By studying the statistical properties of flares on many M dwarfs, we will further our understanding of stellar magnetic activity and how flares are affected by the internal magnetic dynamo.

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