June 14-18, 2026 (Pasadena, CA)

Town Hall: Nancy Grace Roman Space Telescope Town Hall

• Nancy Grace Roman Space Telescope Town Hall

  (Monday, June 15, 12:45–1:45 p.m. PT; Pasadena Convention Center, Ballroom A)

  The Nancy Grace Roman Space Telescope is a NASA flagship mission planned for launch no earlier than September 2026. The Roman Space Telescope will perform breakthrough science in dark energy cosmology, exoplanet microlensing, and NIR sky surveys with its Wide Field Instrument. Roman will also feature the Coronagraph Instrument (CGI), a technology demonstration that will directly image and take spectra of exoplanetary systems using several novel technologies together for the first time in space. This session will cover the status of the project and upcoming opportunities for community involvement in planning and executing the science and technology demonstration aspects of Roman.

• STScI Town Hall

  (Wednesday, June 17, 12:45–1:45 p.m. PT; Pasadena Convention Center, Ballroom A)

  The Space Telescope Science Institute (STScI) serves the astronomical community through the operation of multiple NASA flagship missions including the Hubble, Webb, and Nancy Grace Roman Space Telescopes, the development of the MAST advanced data and science archives, including Kepler and TESS, and the dissemination of astronomical information to the broadest public audiences. Offering this breadth of resources to help the scientific community advance, STScI is the primary user interface for Hubble and Webb, and collaborates with IPAC, Caltech to provide community support for Roman. The STScI Town Hall will serve as the center piece for our AAS 248 presence. We will report on the status of our existing and upcoming missions and describe new opportunities designed to advance astrophysics into the 2030s. In particular, we will focus on the upcoming launch of the Nancy Grace Roman Space Telescope. We will highlight the software and cloud-based analysis tools that will are available to the community through the Roman Nexus and through the Mikulski Archive of Space Telescopes (MAST). We will include progress reports on Hubble and Webb and highlight synergies with the upcoming Habitable Worlds Observatory. We will include time for discussion to receive community input regarding new capabilities and to answer questions about our activities in the coming year.

 

Oral Special Sessions

• Simulated Universes for Precision Cosmology

  (Wednesday, June 17, 10:00–11:30 a.m. PT; Pasadena Convention Center, Ballroom F)

  The coming decade of cosmology will be shaped by the transformative surveys of the Nancy Grace Roman Space Telescope, the Vera C. Rubin Observatory, Euclid, SPHEREx, DES, and DESI. Realizing their full scientific potential requires sophisticated simulated skies -- catalogs and images that capture survey strategies, astrophysical complexity, and instrumental systematics at the level demanded by precision cosmology. This special session will bring together developers and users of simulated data products that enable cosmological analyses of observational data. We aim to highlight end-to-end image simulations, mock galaxy and shear catalogs, synthetic spectrophotometric data sets, and cross-survey simulation efforts that support studies of dark energy, large-scale structure, weak lensing, and systematic-error control. Beyond presenting existing products, this session will emphasize the infrastructure that makes the production of such simulations possible and sustainable. As survey data volumes and analysis complexity grow, coordinated infrastructure for simulation generation, validation, distribution, and reuse will be essential. Lessons learned from simulations and mock catalogs, including key systematics, for Stage 3 surveys (in particular, DES and DESI) will also be incorporated into the session. By fostering dialog between simulation builders and analysis teams, this session aims to help define a durable foundation for the next generation of cosmological simulations.

  • Galaxy Simulations for the Roman High Latitude Survey - Diana Scognamiglio (Duke Univ.)

    (Wednesday, June 17, 10:05–10:19 a.m. PT; Pasadena Convention Center, Ballroom F)

    Upcoming weak lensing analyses with the Nancy Grace Roman Space Telescope require highly realistic image simulations to control shear systematics at unprecedented precision. In this talk, I will provide an update on ongoing simulation efforts for Roman, before focusing in particular on DDPM-generated Roman-like galaxy populations and their applications to weak lensing analyses. We have developed a diffusion-based framework to generate multi-band galaxy simulations (Y, J, H) tailored for the Roman High Latitude Survey, capturing the complex, non-parametric morphologies of real galaxies. The model is trained on James Webb Space Telescope/NIRCam observations processed to match Roman’s resolution and noise properties, enabling the generation of synthetic postage stamps that bypass the limitations of parametric approaches. Validation against independent datasets demonstrates that the model accurately reproduces both the marginal distributions and covariance structure of key observables, including magnitude, size, ellipticity, and color. These results highlight the potential of diffusion models as a scalable, high-fidelity solution for calibrating weak lensing pipelines and supporting next-generation cosmological surveys.

  • Multi-survey joint analysis of galaxy formation physics across 12 billion years of cosmic history - Kaustav Mitra (Argonne National Lab) et al.

    (Wednesday, June 17, 10:19–10:33 a.m. PT; Pasadena Convention Center, Ballroom F)

    We present Diffsky, an empirical modelling of spectral energy distributions (SEDs) of galaxies linked to the co-evolution of their host dark matter halos. The modeling framework populates simulated or Monte Carlo halo merger trees with galaxy SEDs across lightcones spanning any redshift range. I will highlight the ongoing work at Argonne National Lab to accelerate lightcone generation and simultaneous modelling of multi-wavelength, multi-survey datasets. In particular, I will introduce DisCoWebS, Diffsky fit to Cosmos-Web and SDSS, to jointly constrain galaxy formation physics across 12 billion years of cosmic history. These constraints enable the creation of highly realistic OpenUniverse mock catalogs, essential for validation pipelines of current and upcoming cosmological surveys such as DESI, Rubin, Roman, and Euclid.

• How JPL Advances The Astronomical Community’s Scientific Ambitions

  (Wednesday, June 17, 2:00–3:30 p.m. PT; Pasadena Convention Center, Ballroom G)

  2026 marks the 90th anniversary of the founding of the Jet Propulsion Laboratory which started with a few “rocket-men” from the California Institute of Technology testing rocket engines in the canyons above Pasadena. Since those modest beginnings, JPL has partnered with NASA, Caltech, the broader scientific community, and industry to make seminal advances in solar system science, earth science, and astrophysics. From the US’s first orbiting satellite, Explorer 1, and humanity’s first interstellar probes, the still -operating Voyagers 1 and 2, to the first interplanetary helicopter and cryogenic telescopes, JPL has enabled breakthroughs across space science. JPL’s technology and engineering expertise has been at the heart of these developments with JPL scientists providing the critical link between scientific aspirations and engineering reality. The session aims to increase the community’s awareness of JPL’s expertise across the wide variety of technologies critical to current or prospective missions. Attendees will have an opportunity to interact with JPL scientists, technologists and engineers to understand how JPL’s skills might be brought to bear on projects ranging in scope from Pioneer and Explorers to future flagships.
  Speakers will link technological advances to past successes and future challenges:

  1. Cryogenic expertise developed over four decades: from IRAS and Spitzer to WISE and the MIRI instrument on JWST, from SPHEREx to the proposed PRIMA Probe.
  2. The development of high-performance imaging optical systems from WFPC-2 on the Hubble Space Telescope, the Coronagraph Instrument on the Roman Space Telescope and the future challenges of detecting a habitable Earth 2.0 with the Habitable Worlds Observatory.
  3. The development of low noise detectors from submillimeter wavelengths to the ultraviolet.
  4. The importance of robust system engineering to successful space missions, from small Explorers to NASA flagships.
  5. How the scientific community partners with JPL to realize its scientific ambitions.

 

Oral Session Talks

• Roman GBTDS Data Products from the SSC MSOS Pipeline - Jennifer Sobeck (Caltech/IPAC) et al.

  (Monday, June 15, 10:20–10:30 a.m. PT; Pasadena Convention Center, Ballroom C)

  The Nancy Grace Roman Space Telescope, the next NASA flagship mission set to launch by May 2027, will be a powerful observatory for exploring the time-varying Universe. The Roman Galactic Bulge Time Domain Survey (GBTDS) will acquire high-cadence, near-infrared photometric observations for 6 fields in the Milky Way bulge, including a Galactic Center pointing. The Roman Science Support Center (SSC) at IPAC is responsible for the development and operation of the Microlensing Science Operations System (MSOS), which will perform the advanced processing of GBTDS data. This presentation will give an overview of all MSOS pipeline components as well as provide detailed descriptions of the MSOS image and catalog products.

• Explosive Transients and the High-z Universe with JWST and Roman - Ori Fox & Armin Rest (STScI).

  (Tuesday, June 16, 10:00–10:10 a.m. PT; Pasadena Convention Center, Ballroom A)

  Transient astronomy in the early Universe (z > 2) remains largely unexplored, lying beyond the rest-frame optical spectroscopic reach of most current observatories. Yet this regime promises transformative insights, with high-redshift transients providing direct access to the early Universe and enabling studies of how stellar populations and cosmology evolve over cosmic time. Here we present the discovery potential of both the Webb and Roman Space Telescopes. We focus on an initial JWST pathfinder program, covering an area of ~133 arcmin^2 (~0.037 deg^2) independently imaged by the PRIMER and COSMOS-Web extragalactic programs, leading to the discovery of 68 supernovae (SNe) with host photometric redshifts reaching z < 5. Among the most notable sources are a relatively bright, blue CCSN at z > 3 (SN 2023aeab) and a young, normal SN Ia at z > 2 (SN 2023aeax). While this pathfinder effort is limited in cadence and number of filters, it demonstrates the strong potential of a dedicated, well-planned time-domain survey to obtain the sample sizes and rate measurements needed to chart SN populations deep into the early Universe. We go on to discuss the Roman hIgh-redshift transient SciencE (RISE) program, a new Roman WFI initiative designed to deliver to the community deep stacked imaging, image subtraction, and faint alert streams that extend beyond single-epoch detections. In combination with JWST and Rubin Observatory observations, RISE will unlock a statistically robust view of transient populations across cosmic time and open a new frontier in high-redshift time-domain astrophysics.

• Preparing for NASA’s Roman Space Telescope Launch and First Images: Outreach and Event Resources for Engaging the Public - Quyen Hart (STScI) et al.

  (Tuesday, June 16, 2:10–2:20 p.m. PT; Pasadena Convention Center, Ballroom C)

  NASA’s next flagship astrophysics observatory, the Nancy Grace Roman Space Telescope, will launch soon! This presentation shares the Roman Community Events effort, which is providing STEM learning sites across the country (including museums, planetariums, and libraries) with the information and resources needed to host Roman launch and First Look Observations events. This effort is a partnership between the NASA Roman mission and NASA’s Universe of Learning STEM learning program. The resources and information provided from this presentation will include information on how the astronomical community can engage their local communities. Roman will advance our understanding of the cosmos through large optical, near-infrared, and spectroscopic surveys of the universe with its Wide Field Instrument and provide a technology demonstration of a next-generation coronagraph. Via Roman’s wide field camera, the observatory is designed to survey the sky 1,000 times faster than Hubble with comparable image resolution in the near-infrared. The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA's Jet Propulsion Laboratory in Southern California; Caltech/IPAC in Pasadena, California; the Space Telescope Science Institute in Baltimore, Maryland; and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems, Inc. in Boulder, Colorado; L3Harris Technologies in Rochester, New York; and Teledyne Scientific & Imaging in Thousand Oaks, California. This presentation is partially based on work performed as part of the NASA’s Universe of Learning project and is supported by NASA under cooperative agreement award number NNX16AC65A. The NASA's Universe of Learning project creates and delivers science-driven, audience-driven resources and experiences designed to engage learners of all ages and backgrounds in exploring the universe for themselves. The competitively selected project represents a unique partnership between the Space Telescope Science Institute, Caltech/IPAC, Smithsonian Astrophysical Observatory, and Jet Propulsion Laboratory, and is part of the NASA Science Mission Directorate Science Activation program.

 

iPoster Sessions

• The Roman Spectroscopic Calibration Data Pipeline - Greg Walth (Caltech/IPAC)

  (Wednesday, June 17, 9:00–10:00 a.m. PT; Pasadena Convention Center, Exhibit Hall A)

  The Nancy Grace Roman Space Telescope, set to launch at the end of 2026, will revolutionize slitless spectroscopic surveys. One of the core community surveys, the High Latitude Wide Area Survey (HLWAS), is designed to the unravel the mystery of dark energy by measuring the redshifts of ~19 million galaxies. The HLWAS will cover 2400 deg2 using near-IR (1−1.9 micron) grism spectroscopy during its 5 year mission. In order to achieve these precise measurements it will require high fidelity calibrations. The Calibration Data Pipeline (CDP) will play a key role in providing the necessary calibrations for the Grism and Prism Data Processing System (GDPS). The CDP is designed to create the following slitless spectroscopic calibrations; small-scale flatfield (pixel level flat), direct-to-dispersed mapping, spectral trace, spectral PSF, wavelength calibration, relative flux calibration (large scale flat), and absolute flux calibration. In this presentation we will present the CDP and its planned operation during flight.

• An Overview of the Roman GBTDS MSOS Pipelines: Detection Efficiency and Data Quality Assessment - Rachel Akeson (Caltech/IPAC) et al.

  (Wednesday, June 17, 5:30–6:30 p.m. PT; Pasadena Convention Center, Exhibit Hall A)

  One of the community surveys to be conducted by the Nancy Grace Roman Space Telescope is the Galactic Bulge Time Domain Survey (GBTDS), which will produce high-cadence imaging of a ~1.7 square degree area near the center of the Milky Way and for a Galactic Center field. The Science Support Center (SSC) at IPAC is responsible for the Microlensing Science Operations System (MSOS) and will produce the high-level data products from the GBTDS. We present details for two of the components of the MSOS pipeline: the microlensing detection efficiency (DE) and the data quality assessment (DQA). We describe the methods that will be performed by the DE pipeline, including pixel-level injection, light-curve-level injection, and the Rhie method. In addition, we will present the DQA that will be performed on the photometry data products. For both pipelines, we provide information on the data products that will be delivered to the community via the Roman archive at MAST.

• MSOS Photometry Pipeline for the Roman Galactic Bulge Time Domain Survey - Sebastiano Calchi Novati (Caltech/IPAC) et al.

  (Wednesday, June 17, 5:30–6:30 p.m. PT; Pasadena Convention Center, Exhibit Hall A)

  The Roman Space Telescope Galactic Bulge Time Domain Survey (GBTDS) will produce high-cadence imaging of a ~1.7 square degree area near the center of the Milky Way and for a Galactic Center field. The Science Support Center (SSC) at IPAC is responsible for the Microlensing Science Operations System (MSOS), which will process the data from the GBTDS. We present the MSOS Photometry Pipeline responsible to process input Roman WFI Level-2 data (the calibrated detector rate images) to produce Level-3 (re-pixelated coadded images) and Level-4 (catalogs) photometry products. We present preliminary results based on simulated data and provide information on the design of the data products which will be delivered to the community.

 

Exhibitor Theater (Pasadena Convention Center Exhibit Hall, Booth 209)

• "The Roman Space Telescope is Almost Here. Are you ready?" - Ori Fox (STScI)

June 15, 9:30-10:00 a.m. PT

• "Get Set for the Roman Space Telescope Coronagraph Instrument" - Alexandra Greenbaum (Caltech/IPAC)

June 16, 9:30-10:00 a.m. PT