Airborne Telescopes Research Articles

Seeing Green: A Stratospheric View of the 2017 Total Eclipse

Airborne telescopes gave scientists a sky-high view of the 2017 Great American Eclipse as they took measurements that are difficult to obtain from the ground.

Star Formation at Dome C: Sub-millimeter Line Observations

Dome C is one of the best sites on the Earth for carrying out sub-millimeter astronomical observations. Specifically, given the extremely dry atmosphere, the Tera-Hertz bands at 1000, 1300 and 1500 GHz, open up for a reasonable fraction of the time. Since these bands are presently almost not observable with ground based telescopes elsewhere on the Earth, observations in those bands have been only possible with airborne and/or satellite telescopes so far. This implies indeed that very few observations have been carried out in those bands, and with very reduced spatial and spectral resolutions, although some important molecular transitions fall there. In this contribution, we review the studies relevant to the Star Formation topics, which can be done in the three Tera-Hertz bands, and compare with existing and/or planned facilities. In particular, we consider the two proposed possibilities of a 12 m single dish operating in the three bands (ASO proposal: see Olmi contribution), and of an 2 m antennae interferometer operating at 1500 GHz (HEAT, a variation of the API proposal: see Swain contribution). In our opinion, the second possibility has a greater chance to provide really unique observations with respect to existing or planned facilities in the sub-millimeter range.

Observations of Water and Molecular Oxygen in the Interstellar Gas

Water and molecular oxygen are two simple molecules which are not easily observed in the interstellar medium. O2 emissions have yet to be detected from interstellar space, and H2O has been observed only in rather special environments where the interstellar gas has been warmed by embedded infrared sources or by shock waves. This sorry state of affairs does not necessarily reflect a low interstellar abundance for these species, but rather is a consequence of the very high abundance of O2 and H2O within our own atmosphere: strong atmospheric absorption lines make it extremely difficult to carry out observations of water and molecular oxygen emissions using ground-based or even airborne telescopes. Future observations from two orbiting telescopes scheduled for launch in the coming five years - the Infrared Space Observatory (ISO) and the Submillimeter Wave Astronomy Satellite (SWAS) - promise to improve radically the observational data on H2O and O2.

Infrared Astronomy After IRAS

The 250,000 sources in the recently issued Infrared Astronomy Satellite (IRAS) all-sky infrared catalog are a challenge to astronomy. Many of these sources will be studied with existing and planned ground-based and airborne telescopes, but many others can no longer even be detected now that IRAS has ceased to operate. As anticipated by advisory panels of the National Academy of Sciences for a decade, study of the IRAS sources will require the Space Infrared Telescope Facility (SIRTF), a cooled, pointed telescope in space. This instrument may be the key to our understanding of cosmic birth-the formation of planets, stars, galaxies, active galactic nuclei, and quasars. Compared with IRAS and existing telescopes, SIRTF's power derives from a thousandfold gain in sensitivity over five octaves of the spectrum.

Infrared Fourier spectrometer for airborne and ground-based astronomy

A unique high resolving power near-infrared, astronomical Fourier spectrometer has been constructed foruse at both ground-based and airborne telescopes. Its capabilities include a limiting resolution of 0.01 cm(-1) and spectral coverage over the InSb detector sensitivity region (0.8-5.6 microm). The instrument is optimized for operation in environments inaccessible to other high-resolution Fourier spectrometers, namely, the Cassegrain focuses of conventional telescopes and the NASA Kuiper Airborne Observatory's 91-cm telescope. Details of the spectrometer are discussed, and various astronomical and laboratory spectra are presented.

Fluctuating sky emission in airborne infrared astronomy: Measurements and interpretation

During a Spacelab simulation mission onboard the CV-990 aircraft a number of measurements have been performed to investigate the so-called sky-noise, a phenomenon limiting astronomical observations carried out with airborne telescopes. The experimental system consisted of a 32-cm telescope and a four channel infrared photometer equipped with a field-of-view selector. The data show that the sky-noise depends on the chopping frequency, the wavelength and the field-of-view. The work has been carried out taking into account a number of stratospheric environmental parameters. Beside this a turbulent model of the stratosphere has been developed, which appears to be consistent with the observations and suggests future developments.

The outer solar system

During the last 5 years, our knowledge about the outer solar system has increased tremendously, owing largely to the application of increasingly sophisticated observational techniques with ground‐based and air borne telescopes. We have also witnessed the beginning of direct investigation with the successful Jupiter flybys of the U.S. spacecraft Pioneer 10 and 11. The first of these vehicles is on its way to solar system escape, while the second is targeted for Saturn. The next generation of missions will be twin Mariner‐class spacecraft to be launched in 1977 for further investigation of Jupiter (1979) and Saturn (1981) and their satellites. We may expect large gains in information from continued ground‐based studies during this same time period.