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Type-I Superluminous Supernovae (SLSNe) are an exotic class of core-collapse SN (CCSN) that can be up to 100 times brighter and more slowly-evolving than normal CCSNe. SLSNe represent the end-stages of the most massive stripped stars, and are thought to be powered by the spin-down energy of a millisecond magnetar. Studying them and measuring their physical parameters can help us to better understand stellar mass-loss, evolution, and explosions. Moreover, thanks to their high luminosities, SLSNe can be seen up to greater distances, allowing us to explore how stellar physics evolves as a function of redshift. The High Latitude Time Domain Survey (HLTDS) will provide us with an exquisite dataset that will discover 100s of SLSNe. Here, we focus on the question of which sets of filters and cadences will allow us to best characterize the physical parameters of these SLSNe. We simulate a set of SLSNe at redshifts ranging from z = 0.1 to z = 5.0, using six different sets of filters, and cadences ranging from 5 to 100 days. We then fit these simulated light curves to attempt to recover the input parameter values for their ejecta mass, ejecta velocity, magnetic field strength, and magnetar spin period. We find that four filters are sufficient to accurately characterize SLSNe at redshifts below $z = 3$, and that cadences faster than 20 days are required to obtain measurements with an uncertainty below 10\%, although a cadence of 70 days is still acceptable under certain conditions. Finally, we find that the nominal survey strategy will not be able to properly characterize the most distant SLSNe at $z = 5$. We find that the addition of 60-day cadence observations for 4 years to the nominal HLTDS survey can greatly improve the prospect of characterizing these most extreme and distant SNe, with only an 8\% increase to the time commitment of the survey., Comment: Submitted as part of the Nancy Grace Roman Space Telescope's Core Community Surveys call for white papers

We present new spectroscopic and photometric follow-up observations of the known sample of extreme coronal line emitting galaxies (ECLEs) identified in the Sloan Digital Sky Survey (SDSS). With these new data, observations of the ECLE sample now span a period of two decades following their initial SDSS detections. We confirm the nonrecurrence of the iron coronal line signatures in five of the seven objects, further supporting their identification as the transient light echoes of tidal disruption events (TDEs). Photometric observations of these objects in optical bands show little overall evolution. In contrast, mid-infrared (MIR) observations show ongoing long-term declines. The remaining two objects had been classified as active galactic nuclei (AGN) with unusually strong coronal lines rather than being TDE related, given the persistence of the coronal lines in earlier follow-up spectra. We confirm this classification, with our spectra continuing to show the presence of strong, unchanged coronal-line features and AGN-like MIR colours and behaviour. We have constructed spectral templates of both subtypes of ECLE to aid in distinguishing the likely origin of newly discovered ECLEs. We highlight the need for higher cadence, and more rapid, follow-up observations of such objects to better constrain their properties and evolution. We also discuss the relationships between ECLEs, TDEs, and other identified transients having significant MIR variability., Comment: Submitted to MNRAS. 33 pages, 15 figures

Upcoming optical surveys such as the Large Synoptic Survey Telescope will discover supernovae at rates far out-pacing feasible spectroscopic classification. It is therefore critical that we optimize alternate classification methods using all available information. The use of host galaxy data for classification has not been well-developed, despite well-known trends between host galaxy properties and supernova types, and machine learning methods are well suited to this task of identifying complex trends. Using Pan-STARRS1 Medium-Deep Survey (PS1-MDS) images, we trained machine learning algorithms to predict supernovae types using solely contextual information. In particular, we present a random forest classier using known host galaxy properties, and a convolutional neural network using host galaxy images. Classifying between types Ia, Ibc, II, IIn, and superluminous, we find the convolutional neural network performs significantly better than the random forest classier. They achieve average accuracies per class of 63% and 47% respectively. The convolutional neural network performs similarly across most classes with accuracies above 50%, whereas the random forest struggles to classify types IIn and Ibc. Classifying between supernovae Ia and all other types, we achieve similar accuracy with both algorithms, with 70% in the random forest and 74% in the CNN. This is a significant improvement from existing host-galaxy based classification work (Foley and Mandel 2013). Future work includes combining our algorithms with photometric classification pipelines for optimized classification., Astro 98, {"references":["Abadi, M., Agarwal, A., Barham, P., et al. 2015, TensorFlow: Large-Scale Machine Learning on Heterogeneous Systems. https://www.tensor ow.org/","Barbary, K. 2016, J. Open Source Software, 1, 58","Bertin, E., & Arnouts, S. 1996, Astronomy and Astrophysics Supplement Series, 117, 393","Blondin, S., & Tonry, J. 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We present X-ray and multi-band optical observations of the afterglow and host galaxy of GRB 180418A, discovered by ${\it Swift}$/BAT and ${\it Fermi}$/GBM. We present a reanalysis of the GBM and BAT data deriving durations of the prompt emission of $T_{90}\approx$2.56s and $\approx$1.90s, respectively. Modeling the ${\it Fermi}$/GBM catalog of 1405 bursts (2008-2014) in the Hardness-$T_{90}$ plane, we obtain a probability of $\approx$60% that GRB 180418A is a short-hard burst. From a combination of ${\it Swift}$/XRT and ${\it Chandra}$ observations, the X-ray afterglow is detected to $\approx$38.5 days after the burst, and exhibits a single power-law decline with $F_{\rm X} \propto t^{-0.98}$. Late-time Gemini observations reveal a faint r$\approx$25.69 mag host galaxy at an angular offset of $\approx$0.16''. At the likely redshift range of z$\approx$1-2.25, we find that the X-ray afterglow luminosity of GRB 180418A is intermediate between short and long GRBs at all epochs during which there is contemporaneous data, and that GRB 180418A lies closer to the $E_{\gamma,{\rm peak}}-E_{\gamma,{\rm iso}}$ correlation for short GRBs. Modeling the multi-wavelength afterglow with the standard synchrotron model, we derive the burst explosion properties and find a jet opening angle of $\theta_{\rm j} \gtrsim 9-14^{\circ}$. If GRB 180418A is a short GRB that originated from a neutron star merger, it has one of the brightest and longest-lived afterglows along with an extremely faint host galaxy. If instead the event is a long GRB that originated from a massive star collapse, it has among the lowest luminosity afterglows, and lies in a peculiar space in terms of the Hardness-$T_{90}$ and $E_{\gamma,{\rm peak}}-E_{\gamma,{\rm iso}}$ planes., Comment: 26 pages, 9 figures, 3 tables (Accepted, ApJ)

Massive, rapidly-spinning magnetar remnants produced as a result of binary neutron star (BNS) mergers may deposit a fraction of their energy into the surrounding kilonova ejecta, powering a synchrotron radio signal from the interaction of the ejecta with the circumburst medium. We present 6.0 GHz Very Large Array (VLA) observations of nine, low-redshift short gamma-ray bursts (SGRBs; $z, 21 pages, 7 figures, submitted to ApJ

Long gamma-ray bursts (GRBs) are the most luminous known electromagnetic radiation sources in the Universe for the 3 to 300 sec of their prompt flashes (isotropic X/ gamma-ray luminosities up to 10^53 ergs/sec). Their afterglows have first day rest-frame UV/optical absolute magnitudes AB = -30 to -23. This luminous continuum nUV-nIR back-light provides the ultimate probe of the SFR(z) back to the first Pop III to II.5 stars, expected to be massive and GRB progenitors. GRB afterglow spectra in the first 1 to 3 hours will directly measure their host galaxy ionization fraction x_i vs. z in the Epoch of Reionization (EOR), tracing the growth of structure. Only 28% of Swift GRBs have measured redshifts due to limited followup at R, J >21. Some ~25% of GRBs are optically dark due to dust absorption in their host galaxies, but those with low NH in their X-ray spectra are likely at z >7. Current 8-10m telescopes and coming ELTs cannot pursue optically dark GRBs promptly, nor can JWST or WFIRST slew within 0.5 to 1 days of a GRB. The Time-domain Spectroscopic Observatory (TSO) is a proposed Probe-class 1.3m telescope at L2, with imaging and spectroscopy (R = 200, 1800) in 4 bands (0.3 to 5um) and rapid slew capability to 90% of sky. TSO would finally utilize z > 6 to 12 GRBs as the most direct probe of the SFR(z), EOR(z), and possibly the first direct detection of the core collapse of the very first (Pop III) stars., 5 pages, 3 figures, Science White Paper submitted to the Astro2020 Decadal Survey

Time-domain Astrophysics (TDA), a foundation of Astronomy, has become a major part of current and projected (2020s) astrophysics. While much has been derived from temporal measures of flux and color, the real physics comes from spectroscopy. With LSST coming on line in 2022, with TDA as one of its original drivers, the deluge of Transients and new types of variables will be truly astronomical. With multi-wavelength targeted EM surveys and multi-messenger (e.g. LIGO-international and advanced ICECUBE), and the possibility of full-sky and full-time X-ray imagers, the discovery of new Transients and Variables will flood telescopes on the ground and in space, and this just for multi-band imaging without spectroscopy. In this White Paper we briefly summarize several long-standing major science objectives that can be realized with TDA imaging and spectroscopy (near UV to mid IR) from space. We provide a brief description of how these can be achieved with the Time-domain Spectroscopic Observatory (TSO), a Probe-Class mission concept that ELTs on the ground and Flagship missions in space can not achieve on their own., Comment: Science White Paper submitted (edited) to Astro2020 Decadal Survey. 4 pages, 2 figures, 2 Tables

LISA will open the mHz band of gravitational waves (GWs) to the astronomy community. The strong gravity which powers the variety of GW sources in this band is also crucial in a number of important astrophysical processes at the current frontiers of astronomy. These range from the beginning of structure formation in the early universe, through the origin and cosmic evolution of massive black holes in concert with their galactic environments, to the evolution of stellar remnant binaries in the Milky Way and in nearby galaxies. These processes and their associated populations also drive current and future observations across the electromagnetic (EM) spectrum. We review opportunities for science breakthroughs, involving either direct coincident EM+GW observations, or indirect multimessenger studies. We argue that for the US community to fully capitalize on the opportunities from the LISA mission, the US efforts should be accompanied by a coordinated and sustained program of multi-disciplinary science investment, following the GW data through to its impact on broad areas of astrophysics. Support for LISA-related multimessenger observers and theorists should be sized appropriately for a flagship observatory and may be coordinated through a dedicated mHz GW research center., Comment: Submitted to the Astro2020 Decadal Survey call for science white papers

Radio observations of cool stellar systems provide unique information on their magnetic fields, high-energy processes, and chemistry. Buoyed by powerful new instruments (e.g. ALMA, JVLA, LOFAR), advances in related fields (e.g., the Gaia astrometric revolution), and above all a renewed interest in the relevant stellar astrophysics, stellar radio astronomy is experiencing a renaissance. In this splinter session, participants took stock of the present state of stellar radio astronomy to chart a course for the field's future., Comment: Splinter session summary, to appear in the proceedings of the 20th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun (ed. S. J. Wolk)

We present a nuclear transient event, PS1-13cbe, that was first discovered in the Pan-STARRS1 survey in 2013. The outburst occurred in the nucleus of the galaxy SDSS J222153.87+003054.2 at $z = 0.12355$, which was classified as a Seyfert 2 in a pre-outburst archival Sloan Digital Sky Survey (SDSS) spectrum. PS1-13cbe showed the appearance of strong broad H$\alpha$ and H$\beta$ emission lines and a non-stellar continuum in a Magellan spectrum taken 57 days after the peak of the outburst that resembled the characteristics of a Seyfert 1. These broad lines were not present in the SDSS spectrum taken a decade earlier and faded away within two years, as observed in several late-time MDM spectra. We argue that the dramatic appearance and disappearance of the broad lines and factor of $\sim 8$ increase in the optical continuum is most likely caused by variability in the pre-existing accretion disk than a tidal disruption event, supernova, or variable obscuration. The timescale for the turn-on of the optical emission of $\sim 70$ days observed in this transient is among the shortest observed in a "changing look" active galactic nucleus., Comment: 15 pages, 11 figures, 2 tables

The impending era of wide-field radio surveys has the potential to revolutionize our understanding of astrophysical transients. Here we evaluate the prospects of a wide range of planned and hypothetical radio surveys using the properties and volumetric rates of known and hypothetical classes of extragalactic synchrotron radio transients (e.g., on- and off-axis gamma-ray bursts [GRB], supernovae, tidal disruption events [TDE], compact object mergers). Utilizing these sources and physically motivated considerations we assess the allowed phase-space of radio luminosity and peak timescale for extragalactic transients. We also include for the first time effects such as redshift evolution of the rates, K-corrections, and non-Euclidean luminosity distance, which affect the detection rates of the most sensitive surveys. The number of detected events is calculated by means of a Monte Carlo method, using the various survey properties (depth, cadence, area) and realistic detection criteria that include a cut on the minimum variability of the transients during the survey and an assessment of host galaxy contamination. Near-term GHz frequency surveys (ASKAP/VAST, Very Large Array Sky Survey) will detect few events, Comment: 25 pages, 5 figures, 1 appendix, submitted to ApJ

Long-duration gamma-ray bursts (GRBs) provide a premier tool for studying high-redshift star-forming galaxies thanks to their extreme brightness and association with massive stars. Here we use GRBs to study the galaxy mass-metallicity (M*-Z) relation at z~3-5, where conventional direct metallicity measurements are extremely challenging. We use the interstellar medium metallicities of long-duration GRB hosts derived from afterglow absorption pectroscopy (Z~0.01-1 solar), in conjunction with host galaxy stellar masses determined from deep Spitzer 3.6 micron observations of 20 GRB hosts. We detect about 1/4 of the hosts with I-band absolute magnitudes, M ~ -21.5 to -22.5 AB mag, and place a limit of M>-19 mag on the remaining hosts from a stacking analysis. Using a conservative range of mass-to-light ratios for simple stellar populations (with ages of 70 Myr to ~ 2 Gyr), we infer the host stellar masses and present the galaxy mass-metallicity measurements at z ~ 3-5 ( ~ 3.5). We find that the detected GRB hosts, with M* ~ 2e10 solar masses, display a wide range of metallicities, but that the mean metallicity at this mass scale, Z~ 0.1 solar, is lower than measurements at z < 3. Combined with stacking of the non-detected hosts (with M* < 4e9 solar masses and Z < 0.03 solar), we find evidence for the existence of an M*-Z relation at z ~ 3.5 and continued evolution of this relation to systematically lower metallicities from z ~ 2., Proceedings for a (prize-winning) poster at GRB2010 (Annapolis)

This Cool Stars 16 splinter session was devoted to reviewing our current knowledge of correlated X-ray and radio emission from cool stars in order to prepare for new large radio observatories such as the EVLA. A key interest was to discuss why the X-ray and radio luminosities of some cool stars are in clear breach of a correlation that holds for other active stars, the so-called G\"udel-Benz relation. This article summarizes the contributions whereas the actual presentations can be accessed on the splinter website (http://cxc.harvard.edu/cs16xrayradio/)., Comment: 12 pages, Cool Stars 16 splinter session summary, to appear in conference proceedings

[Abridged] We present the first comprehensive analysis of HST observations of short-duration gamma-ray burst (GRB) host galaxies. These observations allow us to characterize the galactic and local environments of short GRBs as a powerful constraint on the nature of their progenitors. Using the HST data for 10 short GRB hosts we determine the host morphological properties, measure precise physical and host-normalized offsets relative to the galaxy centers, and study the locations of short GRBs relative to their host light distributions. We find that most short GRB hosts have exponential disk profiles, characteristic of late-type galaxies, but with a median size that is twice as large as that of long GRB hosts, commensurate with their higher luminosities. The observed distribution of projected physical offsets, supplemented by ground-based measurements, has a median of ~5 kpc, about 5 times larger than for long GRBs, and in good agreement with predicted offset distributions for NS-NS binary mergers. For the short GRB population as a whole we find the following robust constraints: (i) >25% have projected offsets of 5% have projected offsets of >20 kpc. We find no clear systematic trends for the offset distribution of short GRBs with and without extended soft emission. While the physical offsets are larger than for long GRBs, the distribution of host-normalized offsets is nearly identical due to the larger size of short GRB hosts. Finally, unlike long GRBs, which are concentrated in the brightest regions of their host galaxies, short GRBs appear to under-represent the light distribution of their hosts; this is true even in comparison to core-collapse and Type Ia supernovae. Based on these results, we conclude that short GRBs are consistent with a progenitor population of NS-NS binaries., Version accepted to ApJ

The study of short-duration gamma-ray bursts (GRBs) has undergone a revolution in recent years thanks to the discovery of the first afterglows and host galaxies in May 2005. In this review we summarize our current knowledge of the galactic and sub-galactic environments of short GRBs, and the implications for the progenitor population. The most crucial results are: (i) some short GRBs occur in elliptical galaxies; (ii) the majority of short GRBs occur in star forming galaxies; (iii) the star forming hosts of short GRBs are distinct from the host galaxies of long GRBs in terms of star formation rates, luminosities, and metallicities, and instead appear to be drawn from the general field galaxy population; (iv) the physical offsets of short GRBs relative to their host galaxy centers are significantly larger than for long GRBs; (v) the observed offset distribution agrees well with predictions for the locations of NS-NS binary mergers; and (vi) unlike long GRBs, which tend to occur in the brightest regions of their hosts, the environments of short GRBs generally under-represent the light distribution of their host galaxies. Taken together, these observations suggest that short GRB progenitors have a wide age distribution and generally track stellar mass rather than star formation activity. These results are fully consistent with NS-NS binary mergers, but partial contribution from prompt or delayed magnetar formation is also consistent with the data., Comment: Invited review at "The Shocking Universe" conference, Venice, Italy, September 2009; 19 pages

We spectroscopically study the variability of H-alpha emission in mid- to late-M dwarfs on timescales of ~0.1-1 hr as a proxy for magnetic variability. About 80% of our sample exhibits statistically significant variability on the full range of timescales probed by the observations, and with amplitude ratios in the range of ~1.2-4. No events with an order of magnitude increase in H-alpha luminosity were detected, indicating that their rate is < 0.05 /hr (95% confidence level). We find a clear increase in variability with later spectral type, despite an overall decrease in H-alpha "activity" (i.e., L_{H-alpha}/L_{bol}). For the ensemble of H-alpha variability events, we find a nearly order of magnitude increase in the number of events from timescales of about 10 to 30 min, followed by a roughly uniform distribution at longer durations. The event amplitudes follow an exponential distribution with a characteristic scale of Max(EW)/Min(EW)}-1 ~ 0.7. This distribution predicts a low rate of ~ 10^{-6} /hr for events with (Max(EW)/Min(EW) > 10, but serendipitous detections of such events in the past suggests that they represent a different distribution. Finally, we find a possible decline in the amplitude of events with durations of > 0.5 hr, which may point to a typical energy release in H-alpha events for each spectral type (E_{H-alpha} ~ L_{H-alpha} x t ~ const). Longer observations of individual active objects are required to further investigate this possibility. Similarly, a larger sample may shed light on whether H-alpha variability correlates with properties such as age or rotation velocity., Accepted for publication in ApJ

Over the next decade, we can expect time domain astronomy to flourish at optical and radio wavelengths. In parallel with these efforts, a dedicated transient "machine" operating at higher energies (X-ray band through soft gamma-rays) is required to reveal the unique subset of events with variable emission predominantly visible above 100 eV. Here we focus on the transient phase space never yet sampled due to the lack of a sensitive, wide-field and triggering facility dedicated exclusively to catching high energy transients and enabling rapid coordinated multi-wavelength follow-up. We first describe the advancements in our understanding of known X-ray transients that can only be enabled through such a facility and then focus on the classes of transients theoretically predicted to be out of reach of current detection capabilities. Finally there is the exciting opportunity of revealing new classes of X-ray transients and unveiling their nature through coordinated follow-up observations at longer wavelengths., Comment: 8 pages, 2 figures; White Paper submitted to the Astro2010 SSE panel

We present a high-resolution Keck/ESI spectrum of GRB, which exhibits four absorption systems at z=1.04329, 1.95260, 1.96337, and 1.98691. The two highest redshift systems, separated by about 2400 km/s, have been previously suspected as kinematic features arising in the circumstellar wind around the progenitor star. However, the high column densities of low-ionization species (including possibly neutral hydrogen) in the blue-shifted system, are inconsistent with the expected highly ionized state of the circumstellar wind from the massive progenitor star, even prior to the GRB explosion. This conclusion is also supported by the lack of detectable absorption from fine-structure transitions of SiII and FeII. Instead we conclude that the two redshift systems are similar to multiple DLAs found in QSO sight lines with a similar velocity separation and chemical abundance of [Cr/Fe] and [Zn/Fe]. The absorption system at z=1.96337 is likely an intervening low-mass galaxy, possibly related to the GRB host as part of a forming large-scale structure., Comment: 11 pages, 3 figures; submitted to ApJ

The death of massive stars and the processes which govern the formation of compact remnants are not fully understood. Observationally, this problem may be addressed by studying different classes of cosmic explosions and their energy sources. Here we discuss recent results on the energetics of gamma-ray bursts (GRBs) and Type Ib/c Supernovae (SNe Ib/c). In particular, radio observations of GRB030329, which allow us to undertake calorimetry of the explosion, reveal that some GRBs are dominated by mildly relativistic ejecta such that the total explosive yield of GRBs is nearly constant, while the ultra-relativistic output varies considerably. On the other hand, SNe Ib/c exhibit a wide diversity in the energy contained in fast ejecta, but none of those observed to date (with the exception of SN1998bw) produced relativistic ejecta. We therefore place a firm limit of 3% on the fraction of SNe Ib/c that could have given rise to a GRB. Thus, there appears to be clear dichotomy between hydrodynamic (SNe) and engine-driven (GRBs) explosions, Comment: To appear in proceeding of "3-D signatures in stellar explosions", June 10-13 2003, Austin, Texas, USA

We report VLA radio observations of the Type Ib SN 2016bau (ATel #8818, #8820) in NGC 3631 (distance of 13 Mpc, according to NED). We observed the position of the supernova with VLA at a mid-time of 2016 March 30.42 UT utilizing two basebands of ~1 GHz bandwidth each, centered at 8.6 & 11.0 GHz. We detect a radio source with a flux density of 1.0 +/- 0.03 mJy in the lower sideband (8.6 GHz) at a position consistent with the optical supernova emission.

We provide an overview of the science case, instrument configuration and project plan for the next-generation ground-based cosmic microwave background experiment CMB-S4, for consideration by the 2020 Decadal Survey., Comment: Project White Paper submitted to the 2020 Decadal Survey, 10 pages plus references. arXiv admin note: substantial text overlap with arXiv:1907.04473

The population of stellar black holes (SBHs) in the Galaxy and galaxies generally is poorly known in both number and distribution. SBHs are the fossil record of the massive stars in galaxy evolution and may have produced some (if not all) of the intermediate mass (\gsim100\Msun) black holes (IMBHs) and, in turn, the central supermassive black holes (SMBHs) in galactic nuclei. For the first time, a Galaxy-wide census of accreting black holes, and their more readily recognizable tracer population, accreting neutron stars (NSs), could be measured with a wide-field hard X-ray imaging survey and soft X-ray and optical/IR prompt followup -- as proposed for the EXIST mission., Comment: 8 pages. White Paper submitted February 25, 2009, to Science Frontier Panels (SSE, GAN and GCT) for Astro2010 Decadal Survey

Core-collapse supernovae (SNe) are the highly energetic explosions of massive stars (≳ 8 M☉) that are pervasive in their influence throughout astrophysics. They are the phenomenon with primary responsibility for enriching the universe with many of the heavy elements (like carbon and oxygen) that are needed for life, provide a critical feedback pressure which helps to shape the galaxies that host them, and are the likely formation mechanism for stellar mass black holes. In the past decade, the study of these explosions has been revolutionized by the advent of wide field, untargeted transient searches like Pan-STARRS1 (PS1). These new searches permit the discovery of SNe at unprecedented rates, and absent of many of the selection effects that have enforced biases on past, targeted transient searches. This thesis presents a broad survey of core-collapse SN phenomenology exhibited in the discoveries of untargeted searches, and statistically quantifies population properties of these explosions that link them to distinct classes of progenitor stars. Through studies of the host galaxy and explosion properties of extreme PS1-discovered events, and controlled samples of specific classes of core-collapse objects, we constrain the effect of progenitor star chemical composition (metallicity) on their eventual death states. We provide a new observational, photometric tool which lowers the cost of precisely and accurately measuring the metallicities of distant galaxies and supernova host environments. Moreover, we develop and apply a novel, multi-level Bayesian model for optical transient light curves which we apply to simultaneously interpret more than 20,000 PS1 images. This study illustrates how population-level modeling of data from large photometric surveys can yield improved physical inference on their progenitor stars through comparison to physical models. In the coming era, as next-generation facilities like the Large Synoptic Survey Telescope come online, the supernova discovery rate will accelerate, far outpacing the community's capacity for detailed individual observational follow-up. New observational and statistical tools like those presented here will be critical to enable the next generation of studies in supernova astrophysics.

An understanding of M dwarf stars, the most abundant type of star in our Galaxy, are essential to the understanding of our universe. Studying M dwarf flares and variability provides insight into two important fields. First, M dwarf variability can be used to measure the properties of the magnetic fields and chromospheres of the least massive stars. Second, studying flares in these stars serves as a guide for the feasibility of habitability of exoplanets orbiting in the compact habitable zones of low-mass stars. Using data from the medium-deep fields of the Pan-STARRS survey on Mount Haleakala, Hawaii, we have created a large statistical catalog of M0-M9 type stars in the g,r,i,z, and y bands in order to facilitate the study of short time-scale variability of M dwarfs in the time domain. The medium deep survey allows for detailed and sustained observation of the stars, as this area of the sky was imaged about every other night for four years. This paper outlines the method used to identify and classify the M dwarfs from the photometric images obtained of the medium deep fields. The projected statistical sample achieved is about 800,000 M dwarfs of varying class out of a set of about 9,600,000 detected objects in the survey. We will use this catalog to create light curves encompassing about 500 points over 3 years for each M dwarf, facilitating the study of the variability of the star in the time domain.