PSM2023 Posters

The Fermi Gamma-ray Burst Monitor (GBM) triggers on-board in response to ~ 40 short gamma-ray bursts (SGRBs) per year; however, their large localization regions have made the search for optical counterparts a challenging endeavor. We have developed and executed an extensive program with the wide field of view of the Zwicky Transient Facility (ZTF) camera, mounted on the Palomar 48 inch Oschin telescope (P48), to perform target-of-opportunity (ToO) observations on 15 Fermi-GBM SGRBs during 2018 and 2020-2023. Bridging the large sky areas with small field of view optical telescopes in order to track the evolution of potential candidates, we look for the elusive SGRB afterglows and kilonovae (KNe) associated with these high-energy events. On August 2020, a ZTF-discovered short GRB afterglow showed ambiguous characteristics and late-time photometry unveiled a supernova, making GRB 200826A the shortest duration GRB from a collapsar. Here we discuss the impact of our ToO searches and the prospects of optical GRB science from Palomar observatory.

Palomar is no stranger to exciting Solar System discoveries. Palomar has made headlines and expanded our knowledge of the Solar System such as the discovery of a Jupiter-impacting comet, distant large bodies, and two of five near-Earth asteroid classes in addition to the famous green comet, C/2022 E3 (ZTF), visible to millions of people around the globe. I will describe work leading to some of these discoveries and prospects for the future.

The Transiting Exoplanet Survey Satellite (TESS) has discovered over 250 transiting planets, with more than 6000 candidates yet to be validated. Previous studies have used TESS photometry and statistical tools to quantify the false positive probability (FPP) of TESS candidates. Common types of false positive signals (e.g., eclipsing binary stars) can be ruled out using multi-wavelength transit observations, since the light curves of transiting planets should be nearly achromatic. However, popular statistical tools such as TRICERATOPS currently lack the functionality to incorporate multi-wavelength light curves from ground-based observatories into the calculation of the FPP. These light curves can be significantly more precise than the TESS photometry, and are especially helpful for confirming TESS candidates with low signal-to-noise ratios. In this work, we observed several TESS candidates with Palomar Observatory and modified TRICERATOPS to incorporate these infrared observations. In doing so, we quantify the impact of multi-wavelength observations on the FPPs for these TESS candidates.

Models predict that planets with water-rich compositions may be common around low-mass stars, but definitive evidence for the existence of water worlds has remained elusive. Precise mass and radius measurements for small planets allow us to identify candidate water worlds which have bulk densities too low to be consistent with a rocky composition, and masses too low to retain any H-rich envelope against hydrodynamic escape. Dynamical interactions between adjacent planets in near-resonant multi-planet systems produce transit timing variations (TTVs) that can be observed with high-precision photometry, and measurements of these TTVs can be inverted to produce constraints on planetary densities. For the past two years, the 200-inch Hale Telescope has collected dozens of transit observations for small, Earth-sized exoplanets in nearby multi-planet M dwarf systems. I will discuss some of the promising early results from this survey of candidate water worlds.

We present three classical novae (AT2019qwf, AT2021quw, and AT2022sfe) that erupted within the field of the Transiting Exoplanet Survey Satellite (TESS) and were observed by various instruments. We analyze the mechanism of the eruption with luminosity flares before, during, and after optical maximum, and compare the changes in spectra with respect to time evolution and how these luminosity flares signal change in the eruption, e.g. collisions of mass ejections at different velocities at different points in the process.

The variability of the accretion flow of black holes can be used to probe the accretion flow’s properties. We report on the short-term variability of the non-stellar emission from the quiescent X-ray binary A0620-00. There appears to be quasi-periodic variability on timescales of 30-40 minutes at orbital phases 0.4 < θ < 0.7, but not θ < 0.4. Understanding this dependence on phase will yield insights into quiescent black holes and their accretion flow model.

A key to understanding the weather of Jovian exoplanet atmospheres lies in characterizing microphysical processes that drive condensate cloud formation. In this poster, we discuss how spectro-polarimetric observations of Brown Dwarfs (BDs) can be used to better understand cloud formation and distribution in both BD and giant exoplanet atmospheres, and report the first results of a spectro-polarimetric survey of L/T transition BDs using WIRC+Pol at the 200-inch Hale telescope.

Most stars in the Universe today that have died have become white dwarfs. These simple objects, especially when accreting from a close companion, have shown remarkable diversity through surveys across the electromagnetic spectrum. Polars are systems where a white dwarf with a > 10 MG magnetic field accretes from a donor star. In this poster, I show how the Palomar 48-inch, 60-inch, and 200-inch telescopes have played a crucial role in the discovery and characterization of polars. These systems are everywhere, and ongoing studies are showing the crucial role they play in the final stages of binary star evolution.

White dwarfs with transiting planetary debris offer a window into the late stages of planetary system evolution, as planetary bodies that survived the post-main sequence stages of the host star are scattered onto star grazing orbits and tidally disrupted. We are using a multi-instrument approach involving ZTF, DBSP, CHIMERA, and WIRC to both discover and more fully characterize these systems, to better understand the nature of the objects being accreted by white dwarf stars.

For about a decade starting in 1972 a determined and eclectic group of astronomers used the 200-inmch during twilight hours for observations at 1mm, and, very rarely, at 350um. This poster will review the scientific, technological, and community-building features of this program, which exemplifies the benefits of the 200-inch to Caltech, JPL, and beyond.