Abstract
We present the on-orbit performance of the Colorado Ultraviolet Transit Experiment (CUTE). CUTE is a 6U CubeSat that launched on 2021 September 27 and is obtaining near-ultraviolet (NUV; ...2480 Å-3306 Å) transit spectroscopy of short-period exoplanets. The instrument comprises a 20 cm × 8 cm rectangular Cassegrain telescope, an NUV spectrograph with a holographically ruled aberration-correcting diffraction grating, and an NUV-optimized CCD detector. The telescope feeds the spectrograph through an 18′ × 60″ slit. The detector is a passively cooled, back-illuminated NUV-enhanced CCD. The spacecraft bus is a Blue Canyon Technologies XB1, which has demonstrated ≤ 6″ jitter in 56% of CUTE science exposures. Following spacecraft commissioning, an on-orbit calibration program was executed to characterize the CUTE instrument’s on-orbit performance. The results of this calibration indicate that the effective area of CUTE is ≈19.0–27.5 cm
2
and that the average intrinsic resolution element is 2.9 Å across the bandpass. This paper describes the measurement of the science instrument performance parameters as well as the thermal and pointing characteristics of the observatory.
Abstract We present new near-ultraviolet (NUV, λ = 2479–3306 Å) transmission spectroscopy of KELT-9b, the hottest known exoplanet, obtained with the Colorado Ultraviolet Transit Experiment CubeSat. ...Two transits were observed on 2022 September 28th and September 29th, referred to as Visits 1 and 2 respectively. Using a combined transit and systematics model for each visit, the best-fit broadband NUV light curves are R p / R ⋆ = 0.136 − 0.0146 + 0.0125 for Visit 1 and R p / R ⋆ = 0.111 − 0.0190 + 0.0162 for Visit 2, appearing an average of 1.54× larger in the NUV than at optical wavelengths. While the systematics between the two visits vary considerably, the two broadband NUV light curves are consistent with each other. A transmission spectrum with 25 Å bins suggests a general trend of excess absorption in the NUV, consistent with expectations for ultrahot Jupiters. Although we see an extended atmosphere in the NUV, the reduced data lack the sensitivity to probe individual spectral lines.
Abstract
Atmospheric escape is a fundamental process that affects the structure, composition, and evolution of many planets. The signatures of escape are detectable on close-in, gaseous exoplanets ...orbiting bright stars, owing to the high levels of extreme-ultraviolet irradiation from their parent stars. The Colorado Ultraviolet Transit Experiment (CUTE) is a CubeSat mission designed to take advantage of the near-ultraviolet stellar brightness distribution to conduct a survey of the extended atmospheres of nearby close-in planets. The CUTE payload is a magnifying near-ultraviolet (2479–3306 Å) spectrograph fed by a rectangular Cassegrain telescope (206 mm × 84 mm); the spectrogram is recorded on a back-illuminated, UV-enhanced CCD. The science payload is integrated into a 6U Blue Canyon Technology XB1 bus. CUTE was launched into a polar, low-Earth orbit on 2021 September 27 and has been conducting this transit spectroscopy survey following an on-orbit commissioning period. This paper presents the mission motivation, development path, and demonstrates the potential for small satellites to conduct this type of science by presenting initial on-orbit science observations. The primary science mission is being conducted in 2022–2023, with a publicly available data archive coming online in 2023.
We present new near-ultraviolet (NUV, \(\lambda\) = 2479 \(-\) 3306 \(Å\)) transmission spectroscopy of KELT-9b, the hottest known exoplanet, obtained with the Colorado Ultraviolet Transit Experiment ...(\(CUTE\)) CubeSat. Two transits were observed on September 28th and September 29th 2022, referred to as Visits 1 and 2 respectively. Using a combined transit and systematics model for each visit, the best-fit broadband NUV light curves are R\(_{\text{p}}\)/R\(_{\star}\) \(=\) 0.136\(_{0.0146}^{0.0125}\) for Visit 1 and R\(_{\text{p}}\)/R\(_{\star}\) \(=\) 0.111\(_{0.0190}^{0.0162}\) for Visit 2, appearing an average of 1.54\(\times\) larger in the NUV than at optical wavelengths. While the systematics between the two visits vary considerably, the two broadband NUV light curves are consistent with each other. A transmission spectrum with 25 \(Å\) bins suggests a general trend of excess absorption in the NUV, consistent with expectations for ultra-hot Jupiters. Although we see an extended atmosphere in the NUV, the reduced data lack the sensitivity to probe individual spectral lines.
We present the on-orbit performance of the Colorado Ultraviolet Transit Experiment (\(CUTE\)). \(CUTE\) is a 6U CubeSat that launched on September 27th, 2021 and is obtaining near-ultraviolet (NUV, ...2480 A -- 3306 A) transit spectroscopy of short-period exoplanets. The instrument comprises a 20 cm \(\times\) 8 cm rectangular Cassegrain telescope, an NUV spectrograph with a holographically ruled aberration-correcting diffraction grating, and a passively cooled, back-illuminated NUV-optimized CCD detector. The telescope feeds the spectrograph through an 18\('\) \(\times\) 60\(''\) slit. The spacecraft bus is a Blue Canyon Technologies XB1, which has demonstrated \(\leq\) 6\(''\) jitter in 56% of \(CUTE\) science exposures. Following spacecraft commissioning, an on-orbit calibration program was executed to characterize the \(CUTE\) instrument's on-orbit performance. The results of this calibration indicate that the effective area of \(CUTE\) is \(\approx\) 19.0 -- 27.5 cm\(^{2}\) and that the average intrinsic resolution element is 2.9 A across the bandpass. This paper describes the measurement of the science instrument performance parameters as well as the thermal and pointing characteristics of the observatory.
Atmospheric escape is a fundamental process that affects the structure, composition, and evolution of many planets. The signatures of escape are detectable on close-in, gaseous exoplanets orbiting ...bright stars, owing to the high levels of extreme-ultraviolet irradiation from their parent stars. The Colorado Ultraviolet Transit Experiment (CUTE) is a CubeSat mission designed to take advantage of the near-ultraviolet stellar brightness distribution to conduct a survey of the extended atmospheres of nearby close-in planets. The CUTE payload is a magnifying NUV (2479~--~3306 Ang) spectrograph fed by a rectangular Cassegrain telescope (206mm x 84mm); the spectrogram is recorded on a back-illuminated, UV-enhanced CCD. The science payload is integrated into a 6U Blue Canyon Technology XB1 bus. CUTE was launched into a polar, low-Earth orbit on 27 September 2021 and has been conducting this transit spectroscopy survey following an on-orbit commissioning period. This paper presents the mission motivation, development path, and demonstrates the potential for small satellites to conduct this type of science by presenting initial on-orbit science observations. The primary science mission is being conducted in 2022~--~2023, with a publicly available data archive coming on line in 2023.
We describe the development and implementation of a light-weight, fully autonomous 2-axis pointing and stabilization system designed for balloon-borne astronomical payloads. The system is developed ...using off-the-shelf components such as Arduino Uno controller, HMC 5883L magnetometer, MPU-9150 Inertial Measurement Unit (IMU) and iWave GPS receiver unit. It is a compact and rugged system which can also be used to take images/video in a moving vehicle, or in areal photography. The system performance is evaluated from the ground, as well as in conditions simulated to imitate the actual flight by using a tethered launch.
PDF
