Capturing Early UV Light from Type Ia Supernovae
Type Ia Supernovae (SNe Ia) are the result of a carbon-oxygen rich white dwarf undergoing a thermonuclear runaway. SNe Ia have become one of cosmology's most powerful tools due to their predictability in the optical bandpass, however many details about what leads to the detonation of the white dwarf are currently unknown. An example of a currently outstanding question is whether the white dwarf accretes material from a main sequence or evolved stellar companion, or from another white dwarf. While the optical light curves of SNe Ia are largely the same, their UV light curves have shown to be much more variable. These UV signals are only observable during the first few days after detonation, making rapid identification and targeting crucial. The Ultraviolet-Optical Telescope (UVOT) on board Swift has been the primary observation platform for capturing early near ultraviolet (NUV) due to its ability to rapidly target emerging SNe Ia, however it suffers greatly from a "red leak" which contaminates faint NUV signals from SNe Ia. With the rise of Time Domain and Multi-Messenger (TDAMM) astrophysics, many missions are currently being proposed which are capable of rapid response UV imaging/spectroscopy.
One such proposed rapid response space-based UV instrument is UVIa: the Ultraviolet Type Ia Supernova CubeSat. At the University of Iowa, I participated in the formulation of this CubeSat mission proposal, and designed the three telescopes which make up the instrument payload. UVIa employs double-offset Cassegrain telescopes, consisting of off-axis parabolic primary mirrors and off-axis hyperbolic secondary mirrors, designed to image SNe Ia in the FUV (1500 - 1800 Å), NUV (1800 - 2400 Å), and the Sloan u-band (3000 - 4200 Å) onto CMOS detectors. UVIa additionally serves as a technology development program through the use of novel UV optical coatings, UV enhanced detector coatings, and red light rejecting UV bandpass filters. UVIa also aims to modernize space-based observatory scheduling, and will test new software for autonomous observatory scheduling and targeting similar to ground-based observatory networks. Altogether, UVIa will begin to unravel the mysteries behind SNe Ia while paving the way for future space-based TDAMM astrophysics missions.
One such proposed rapid response space-based UV instrument is UVIa: the Ultraviolet Type Ia Supernova CubeSat. At the University of Iowa, I participated in the formulation of this CubeSat mission proposal, and designed the three telescopes which make up the instrument payload. UVIa employs double-offset Cassegrain telescopes, consisting of off-axis parabolic primary mirrors and off-axis hyperbolic secondary mirrors, designed to image SNe Ia in the FUV (1500 - 1800 Å), NUV (1800 - 2400 Å), and the Sloan u-band (3000 - 4200 Å) onto CMOS detectors. UVIa additionally serves as a technology development program through the use of novel UV optical coatings, UV enhanced detector coatings, and red light rejecting UV bandpass filters. UVIa also aims to modernize space-based observatory scheduling, and will test new software for autonomous observatory scheduling and targeting similar to ground-based observatory networks. Altogether, UVIa will begin to unravel the mysteries behind SNe Ia while paving the way for future space-based TDAMM astrophysics missions.
Observing Procyon with the SISTINE-2 Sounding Rocket
As a graduate student, I had the opportunity to work on the Suborbital Imaging Spectrograph for Transition-region Irradiance from Nearby Exoplanet host stars (SISTINE) sounding rocket. SISTINE is an f/30 imaging spectrograph designed to observe the FUV emission of exoplanet host stars or representative host stars. SISTINE's instrument design allows for spatially resolved FUV spectra of binary star systems at a moderate spectral resolution. This is made possible by several novel technologies, such as enhanced optical coatings which improve FUV reflectivity. These FUV technologies are tested on SISTINE in preparation for future NASA astrophysical missions, such as the Habitable Worlds Observatory (HWO).
I led the assembly, calibration, integration, and launch of the second flight of the payload, SISTINE-2. The science target for this flight was Procyon A, a nearby F-type star that is slightly bigger than the sun and is nearing the end of its life on the main sequence. We successfully captured the FUV spectrum of Procyon A on the night of November 8th, 2021, where we obtained nearly 6 minutes of flight data. Through the use of archival X-ray, extreme ultraviolet (EUV), and NUV observations of Procyon A, along with an optical and infrared (IR) stellar model, the full spectral energy distribution (SED) of Procyon A was developed with the SISTINE-2 flight data. Exoplanet atmospheric models rely heavily on accurate stellar inputs, and proper interpretation of the results also depends on the spectral type of the host star. While SEDs are available for stars similar to the sun or smaller, an SED for an F type star was not available until now. While Procyon A is not currently known to host any exoplanets, the SED was used to characterize the influence on a hypothetical Earth-like planet in the habitable zone of a mid-F host star.
Read more about the instrument buildup and the science results of SISTINE-2!
I led the assembly, calibration, integration, and launch of the second flight of the payload, SISTINE-2. The science target for this flight was Procyon A, a nearby F-type star that is slightly bigger than the sun and is nearing the end of its life on the main sequence. We successfully captured the FUV spectrum of Procyon A on the night of November 8th, 2021, where we obtained nearly 6 minutes of flight data. Through the use of archival X-ray, extreme ultraviolet (EUV), and NUV observations of Procyon A, along with an optical and infrared (IR) stellar model, the full spectral energy distribution (SED) of Procyon A was developed with the SISTINE-2 flight data. Exoplanet atmospheric models rely heavily on accurate stellar inputs, and proper interpretation of the results also depends on the spectral type of the host star. While SEDs are available for stars similar to the sun or smaller, an SED for an F type star was not available until now. While Procyon A is not currently known to host any exoplanets, the SED was used to characterize the influence on a hypothetical Earth-like planet in the habitable zone of a mid-F host star.
Read more about the instrument buildup and the science results of SISTINE-2!
© February 2024