Publications (24)
Fundamental Noise Limits of Infrared Detectors in the Presence of Readout Glow
Michael Bottom, Gustav Pettersson, Pavaman Bilgi +5
Read noise in infrared sensor arrays remains a major obstacle for ground- and space-based astronomy. It has long been recognized that the upcoming extremely large telescopes cannot…
First tests of a 1 megapixel near-infrared avalanche photodiode array for ultra-low background space astronomy
Charles-Antoine Claveau, Michael Bottom, Shane Jacobson +10
Spectroscopy of Earth-like exoplanets and ultra-faint galaxies are priority science cases for the coming decades. Here, broadband source flux rates are measured in photons per squa…
Non-detection of Helium in the upper atmospheres of TRAPPIST-1b, e and f
Vigneshwaran Krishnamurthy, Teruyuki Hirano, Guðmundur Stefánsson +37
We obtained high-resolution spectra of the ultra-cool M-dwarf TRAPPIST-1 during the transit of its planet `b' using two high dispersion near-infrared spectrographs, IRD instrument…
Precision radial velocity measurements by the forward-modeling technique in the near-infrared
Teruyuki Hirano, Masayuki Kuzuhara, Takayuki Kotani +15
Precision radial velocity (RV) measurements in the near-infrared are a powerful tool to detect and characterize exoplanets around low-mass stars or young stars with higher magnetic…
Silicon and Strontium abundances of very metal-poor stars determined from near-infrared spectra
Wako Aoki, Timothy C. Beers, Satoshi Honda +19
Silicon and Strontium are key elements to explore the nucleosynthesis and chemical evolution of the Galaxy by measurements of very metal-poor stars. There are, however, only a few…
Second generation Robo-AO instruments and systems
Christoph Baranec, Reed Riddle, Nicholas M. Law +6
The prototype Robo-AO system at the Palomar Observatory 1.5-m telescope is the world's first fully automated laser adaptive optics instrument. Scientific operations commenced in Ju…
First Detection of Hydroxyl Radical Emission from an Exoplanet Atmosphere: High-dispersion Characterization of WASP-33b using Subaru/IRD
Stevanus K. Nugroho, Hajime Kawahara, Neale P. Gibson +23
We report the first detection of a hydroxyl radical (OH) emission signature in the planetary atmosphere outside the solar system, in this case, in the day-side of WASP-33b. We anal…
Large Adaptive Optics Survey for Substellar Objects (LASSO) Around Young, Nearby, Low-mass Stars with Robo-AO
Maissa Salama, James Ou, Christoph Baranec +16
We present results from the Large Adaptive optics Survey for Substellar Objects (LASSO), where the goal is to directly image new substellar companions (<70 M) at wide orbit…
Two Bright M Dwarfs Hosting Ultra-Short-Period Super-Earths with Earth-like Compositions
Teruyuki Hirano, John H. Livingston, Akihiko Fukui +58
We present observations of two bright M dwarfs (TOI-1634 and TOI-1685: ) hosting ultra-short period (USP) planets, identified by the TESS mission. The two stars are simi…
Glow reduction of ultra-low noise LmAPDs: towards photon counting infrared arrays
Guillaume Huber, Michael Bottom, Charles-Antoine Claveau +5
Spectroscopy and direct-imaging of ultra-faint targets such as Earth-like exoplanets and high redshift galaxies are among the primary goals of upcoming large scale astronomy projec…
Progress towards a megapixel linear-mode avalanche photodiode array for ultra-low background shortwave infrared astronomy
Charles-Antoine Claveau, Michael Bottom, Shane Jacobson +12
Spectroscopy of Earth-like exoplanets and ultra-faint galaxies are priority science cases for the coming decades. Here, broadband source flux rates are measured in photons per squa…
Absence of extended atmospheres in low-mass star radius-gap planets GJ 9827 b, GJ 9827 d and TOI-1235 b
Vigneshwaran Krishnamurthy, Teruyuki Hirano, Eric Gaidos +20
\textit{Kepler} showed a paucity of planets with radii of 1.5 - 2 around solar mass stars but this radius-gap has not been well studied for low-mass star plane…
Visible and Near Infrared Laboratory Demonstration of a Simplified Pyramid Wavefront Sensor
Julien Lozi, Nemanja Jovanovic, Olivier Guyon +4
Wavefront sensing and control are important for enabling one of the key advantages of using large apertures, namely higher angular resolutions. Pyramid wavefront sensors are becomi…
High-speed imaging and wavefront sensing with an infrared avalanche photodiode array
Christoph Baranec, Dani Atkinson, Reed Riddle +4
Infrared avalanche photodiode arrays represent a panacea for many branches of astronomy by enabling extremely low-noise, high-speed and even photon-counting measurements at near-in…
Commissioning results from the Robo-AO-2 facility for rapid visible and near-infrared AO imaging
Christoph Baranec, James Ou, Reed Riddle +16
We installed the next-generation automated laser adaptive optics system, Robo-AO-2, on the University of Hawaii 2.2-m telescope on Maunakea in 2023. We engineered Robo-AO-2 to deli…
LASSO: Large Adaptive optics Survey for Substellar Objects using the new SAPHIRA detector on Robo-AO
Maissa Salama, James Ou, Christoph Baranec +13
We report on initial results from the largest infrared AO direct imaging survey searching for wide orbit (>100 AU) massive exoplanets and brown dwarfs as companions around young ne…
A spectroscopic thermometer: individual vibrational band spectroscopy with the example of OH in the atmosphere of WASP-33b
Sam O. M. Wright, Stevanus K. Nugroho, Matteo Brogi +26
Individual vibrational band spectroscopy presents an opportunity to examine exoplanet atmospheres in detail by distinguishing where the vibrational state populations of molecules d…
Smartphone screens as astrometric calibrators
Aidan Walk, Charles-Antoine Claveau, Michael Bottom +4
Geometric optical distortion is a significant contributor to the astrometric error budget in large telescopes using adaptive optics. To increase astrometric precision, optical dist…
Planet(esimal)s Around Stars with TESS (PAST) III: A Search for Triplet He I in the Atmospheres of Two 200 Myr-old Planets
Eric Gaidos, Teruyuki Hirano, Rena A. Lee +13
We report a search for excess absorption in the 1083.2 nm line of ortho (triplet) helium during transits of TOI-1807b and TOI-2076b, 1.25 and 2.5R planets on 0.55- an…
Limits on the Spin-Orbit Angle and Atmospheric Escape for the 22 Myr-old Planet AU Mic b
Teruyuki Hirano, Vigneshwaran Krishnamurthy, Eric Gaidos +19
We obtained spectra of the pre-main sequence star AU Microscopii during a transit of its Neptune-sized planet to investigate its orbit and atmosphere. We used the high-dispersion n…
Evidence for Spin-orbit Alignment in the TRAPPIST-1 System
Teruyuki Hirano, Eric Gaidos, Joshua N. Winn +21
In an effort to measure the Rossiter-McLaughlin effect for the TRAPPIST-1 system, we performed high-resolution spectroscopy during transits of planets e, f, and b. The spectra were…
Direct Imaging Explorations for Companions from the Subaru/IRD Strategic Program II; Discovery of a Brown-dwarf Companion around a Nearby mid-M~dwarf LSPM~J1446+4633
Taichi Uyama, Masayuki Kuzuhara, Charles Beichman +35
We report the discovery of a new directly-imaged brown dwarf companion with Keck/NIRC2+pyWFS around a nearby mid-type M~dwarf LSPM~J1446+4633 (hereafter J1446). The -band contr…
A Super-Earth Orbiting Near the Inner Edge of the Habitable Zone around the M4.5-dwarf Ross 508
Hiroki Harakawa, Takuya Takarada, Yui Kasagi +46
We report the near-infrared radial-velocity (RV) discovery of a super-Earth planet on a 10.77-day orbit around the M4.5 dwarf Ross 508 (). Using precision RVs f…
Direct Imaging Explorations for Companions around Mid-Late M Stars from the Subaru/IRD Strategic Program
Taichi Uyama, Charles Beichman, Masayuki Kuzuhara +32
The Subaru telescope is currently performing a strategic program (SSP) using the high-precision near-infrared (NIR) spectrometer IRD to search for exoplanets around nearby mid/late…