HIPO in-flight performance aboard SOFIA

Dunham, E. W.; Bida, Thomas A.; Collins, Peter L.; Mandushev, Georgi; McLean, Ian S.; Smith, Erin C.; Taylor, B.; Zoonematkermani, S.

doi:10.1117/12.926749

Cited by 6 publications

(5 citation statements)

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“…The duty cycle for both HIPO channels is essentially 100 percent with a minimal dead time due to the CCD frame transfer of a few milliseconds, because in the frame transfer CCD the readout is overlapped with the next integration. In order to capture the light that is passed through the SOFIA telescope's dichroic tertiary mirror (25% and 45% reflectivity for the B and z' bandpasses; see 20) to the Focal Plane Imager (FPI+) we had planned to save its image data for scientific analysis. Most of the visual light passes the tertiary beam splitter before it is reflected into the Nasmyth tube by the fully-reflective tertiary.…”

Section: Observationmentioning

confidence: 99%

“…portant for bright stars like HD 189733 -here we used the recipe from the aforementioned HIPO exposure time calculator spreadsheet that is based on the findings in (20)), the derived SNR values are adjusted downward to about 1900 in B and 2800 in z ′ . We used these numbers for comparison and also to model photon noise limited lightcurves to test the MCMC fitting routine.…”

Section: Comparison To Expected Photon Noisementioning

confidence: 99%

“…The airborne observatory operates in the wavelength regime where the planet's black-body temperature peaks and contrast ratios between star and planet improve, and the SOFIA telescope also operates at lower temperatures (240K) than ground-based telescopes; therefore the contribution from the thermal background (the dominant noise source for transit observations at wavelengths longer than 3 microns) are significantly reduced. SOFIA can observe simultaneously at infrared and optical wavelengths using its FLITECAM (18) and HIPO (19) instruments in 'FLIPO' mode (20), thereby obtaining light curves for a single transit event over a wide range in wavelength.…”

Section: Exoplanet Observations With Sofiamentioning

confidence: 99%

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First exoplanet transit observation with the Stratospheric Observatory for Infrared Astronomy: confirmation of Rayleigh scattering in HD 189733 b with the High-Speed Imaging Photometer for Occultations

Angerhausen

Mandushev

Mandell

et al. 2015

J. Astron. Telesc. Instrum. Syst

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Here we report on the first successful exoplanet transit observation with the Stratospheric Observatory for Infrared Astronomy (SOFIA). We observed a single transit of the hot Jupiter HD 189733 b, obtaining two simultaneous primary transit lightcurves in the B and z ′ bands as a demonstration of SOFIA's capability to perform absolute transit photometry. We present a detailed description of our data reduction, in particular the correlation of photometric systematics with various in-flight parameters unique to the airborne observing environment. The derived transit depths at B and z ′ wavelengths confirm a previously reported slope in the optical transmission spectrum of HD 189733 b. Our results give new insights to the current discussion about the source of this Rayleigh scattering in the upper atmosphere and the question of fixed limb darkening coefficients in fitting routines.As an airborne observatory, SOFIA has a number of potential advantages for precise time-domain spectrophotometric observations of transiting exoplanets. Ground-based observations are significantly affected by variations of absorption from telluric gases, in particular H 2 O, in the Earth's atmosphere, and these same gases are also the species of interest in exoplanet atmospheres; SOFIA can observe in important atmospheric windows not observable from the ground (14; 15; 16; 17).These are mostly the water bands but also CO, CH 4 , CO 2 are much better mixed and therefore reduce the temporal variation in these bands, which is a crucial point for time-series observations.

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Section: Observationmentioning

confidence: 99%

Section: Comparison To Expected Photon Noisementioning

confidence: 99%

Section: Exoplanet Observations With Sofiamentioning

confidence: 99%

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First exoplanet transit observation with the Stratospheric Observatory for Infrared Astronomy: confirmation of Rayleigh scattering in HD 189733 b with the High-Speed Imaging Photometer for Occultations

Angerhausen

Mandushev

Mandell

et al. 2015

J. Astron. Telesc. Instrum. Syst

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“…However, the most recent Shack-Hartman measurements in 2015 with the High Speed Imaging Photometer for Occultations (HIPO) [Dunham et al (2012)] showed a D(50%) value of about 2.89" (without tilt), mostly due to a high defocus value. In the meantime, the temperature-dependent calibration of the focus position has been improved with°i ght data.…”

Section: Sources Of Image Blur and Imagementioning

confidence: 99%

Image Size and Control System Developments of the Airborne Telescope SOFIA

Graf

Reinacher

Jakob

et al. 2018

J. Astron. Instrum.

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The SOFIA telescope is a worldwide unique observatory that enables infrared astronomy aboard a Boeing 747SP at altitudes of up to 45[Formula: see text]kft. Contrary to any ground-based telescope, SOFIA is exposed not only to aerodynamic forces but also aircraft motion and excitation. Nevertheless, the ambitious scientific goals require a stable platform and very precise pointing. As of now, the telescope can be considered diffraction-limited in the far-infrared wavelengths beyond 50[Formula: see text][Formula: see text]m. A careful study of the different sources of blur revealed that image jitter is among the most influential. During the course of a flight, the telescope is exposed to various excitation levels, leading to deformation of its flexible structure and vibrations in a wide range of frequencies. Since SOFIA entered its operational phase, continuous efforts have been made to develop and implement upgrades in the pointing and control system. The original design was a robust and conservative structure aimed to ensure safe operations with several different science instruments and many unknown parameters. In recent years, more and more agile system components have followed to tackle the residual image motion. This paper introduces the telescope control system followed by a summary of recently installed upgrades and ends with an outlook on future developments on our way to diffraction-limited imaging beyond 25[Formula: see text][Formula: see text]m.

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“…During the summer and fall of 2011, FLITECAM was delivered to SOFIA and co-mounted with HIPO, the High-speed Imaging Photometer for Occultations 7,8 (PI Edward Dunham, Lowell Observatory). HIPO is mounted on-axis and FLITECAM mounts above it.…”

Section: Introductionmentioning

confidence: 99%

FLITECAM: early commissioning results

et al. 2014

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We present a status report and early commissioning results for FLITECAM, the 1-5 micron imager and spectrometer for SOFIA (the Stratospheric Observatory for lnfrared Astronomy). In February 2014 we completed six flights with FLITECAM mounted in the FLIPO configuration, a co-mounting of FLITECAM and HIPO (High-speed lmaging Photometer for Occultations; Pl Edward W. Dunham, Lowell Observatory). During these flights, the FLITECAM modes from -1-4 µm were characterized. Since observatory verification flights in 2011 , several improvements have been made to the FLlTECAM system, including the elimination of a light leak in the FLlTECAM fi lter wheel enclosure, and updates to the observing software. We discuss both the improvements to the FLlTECAM system and the results from the commissioning flights , including updated sensitivity measurements. Finally, we discuss the utility of FLITECAM in the FLIPO configuration for targeting exoplanet transits.

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HIPO in-flight performance aboard SOFIA

Cited by 6 publications

References 0 publications

First exoplanet transit observation with the Stratospheric Observatory for Infrared Astronomy: confirmation of Rayleigh scattering in HD 189733 b with the High-Speed Imaging Photometer for Occultations

First exoplanet transit observation with the Stratospheric Observatory for Infrared Astronomy: confirmation of Rayleigh scattering in HD 189733 b with the High-Speed Imaging Photometer for Occultations

Image Size and Control System Developments of the Airborne Telescope SOFIA

FLITECAM: early commissioning results

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