Major prospects of exoplanet astronomy with the World Space Observatory–UltraViolet mission

Abstract

The success of the International Ultraviolet Explorer (IUE) first and then of the STIS and COS spectrographs on-board the Hubble Space Telescope (HST) demonstrate the impact that observations at UV wavelengths had and are having on modern astronomy. Several discoveries in the exoplanet field have been done at UV wavelengths. Nevertheless, the amount of data collected in this band is still limited both in terms of observed targets and time spent on each of them. For the next decade, the post-HST era, the only large (2-m class) space telescope capable of UV observations will be the World Space Observatory-UltraViolet (WSO-UV). In its characteristics, the WSO-UV mission is similar to that of HST, but all observing time will be dedicated to UV astronomy. In this work, we briefly outline the major prospects of the WSO-UV mission in terms of exoplanet studies. To the limits of the data and tools currently available, here we also compare the quality of key exoplanet data obtained in the far-UV and near-UV with HST (STIS and COS) to that expected to obtain with WSO-UV.

Extreme Water Loss and Abiotic O2Buildup on Planets Throughout the Habitable Zones of M Dwarfs

“…While a large fraction of this oxygen may be removed by surface processes, some exoplanets could retain detectable amounts of O 2 in their atmospheres for extended periods of time. This validates the predictions of Schindler and Kasting (2000), concerning oxygen atmospheres on Venus-like planets, and of Lammer et al (2011a), Lammer et al (2011b), Lammer (2013), and Fossati et al (2014), who argued that oxygenrich atmospheres could develop on G dwarf planets in the HZ, in particular on super-Earths. Our present work could also strengthen the results of Wordsworth and Pierrehumbert (2014) and Tian et al (2014), which indicate that oxygen is not a reliable biosignature; in fact, planets with such elevated quantities of O 2 may be uninhabitable.…”

“…Many of these planets, in particular super-Earths, could retain enough atmospheric O 2 to be spectroscopically detectable by future missions such as the James Webb Space Telescope and World Space Observatory-UltraViolet (Fossati et al, 2014). Our work thus strengthens the results of Wordsworth and Pierrehumbert (2014), Tian et al (2014), andDomagal-Goldman et al (2014), which indicate that O 2 in a planetary atmosphere is not a reliable biosignature; in fact, such elevated quantities of atmospheric oxygen could potentially be an anti-biosignature.…”

Scientific problems addressed by the Spektr-UV space project (world space Observatory—Ultraviolet)

“…Therefore, UV observations will provide the possibility of estimating and placing limits on numerous models for the evolution of planets and their atmospheres currently used to study potential habitability. Thus, UV observations of transits of Earth-like exoplanets around Sun-like stars using Spektr-UV (WSO-UV) will present unique opportunities for shedding light on the early evolution of Earth-like planets, including those in our solar system [275].…”

WSO-UV Space Mission: The State of Art

“…The Instrumentation of the WSO-UV project is very important and helpful for exoplanet studies and the characterization of the exoplanet-stellar environment. However, there are several difficulties that are at the origin of the major uncertainties on any estimations of exoplanetary atmosphere properties (Fossati et al 2014):…”