A dedicated high-resolution spectrograph for surveying helium in exoplanet atmospheres, designed to study atmospheric escape and evolution.
NIGHT (the Near-Infrared Gatherer of Helium Transits) is a narrowband, high-resolution spectrograph, marking the first dedicated survey instrument for exoplanetary atmosphere observations. Developed through a collaboration between the Observatory of Geneva, several other Swiss institutes, and the Université de Montréal, NIGHT aims to conduct an extensive statistical survey of helium atmospheres around 100+ exoplanets over several years.
As the project manager, I lead the development of this instrument from concept to completion. NIGHT will measure absorption from the metastable helium state during exoplanet transits, observable in a triplet of lines around 1083 nm. By focusing specifically on this tracer, we can efficiently survey a large sample of planets to better understand atmospheric escape processes.
Resolution of approximately 75,000, resolving the helium triplet's lineshape and enabling a detailed analysis of the exoplanets thermospheres.
Specialized for a narrow wavelength range around 1083 nm, maximizing efficiency for helium observations.
Approximately 70% throughput for the spectrograph, uniform across wavelength and polarization, outperforming other near-infrared high-resolution spectrographs.
Unique double-pass volume-phase holographic grating configuration to achieve ultra-high spectral resolution while optimizing throughput.
Designed for a multi-year survey of 100+ exoplanets to build a statistical understanding of atmospheric escape.
Efficient, compact instrument that can be deployed on 2-meter class telescopes while achieving sensitivity comparable to 4-meter facilities.
NIGHT comprises three main components:
NIGHT uses a HAWAII-1 1024 × 1024 infrared array, cooled to 85K, while the spectrograph operates at room temperature. A cold heat filter positioned in front of the detector filters out longer infrared wavelengths. Additional short- and longpass filters in the double scrambler filter out our specific wavelength band of interest.
The primary disperser is a high fringe-density volume-phase holographic grating in a double-pass configuration, enabling a spectral resolution of 75,000 while maintaining >80% throughput. This innovative optical design allows NIGHT on a 2-m class telescope to be as sensitive as existing high-resolution spectrographs on 4-m class telescopes.
NIGHT is designed to conduct the first large-scale survey of helium in exoplanet atmospheres. This survey will:
Conceptual design and project planning. Secured initial funding and established collaboration with the Université de Montréal.
Completed optical and mechanical designs. Began procurement of long-lead components. Established initial target selection criteria for the survey.
Finalized all subsystem designs. Began manufacturing of custom components.
Assembly and optical alignment of the spectrograph and front end unit. Commissioning of front end system at the OHP152 telescope.
Instrument testing and characterization. First light observations and commissioning. Beginning of the first survey of 60 nights.
For more information about the NIGHT instrument or potential collaborations, please contact:
Casper Farret Jentink
Project Manager, NIGHT
Email: casper.farret@unige.ch