Ultraviolet Astronomy Archives

July 23, 2024July 23, 2024 by Matt Williams

The Ultraviolet Habitable Zone Sets a Time Limit on the Formation of Life

Artist's impression of the range of habitable zones for different types of stars. Credit: NASA/Kepler Mission/Dana Berry

The field of extrasolar planet studies has grown exponentially in the past twenty years. Thanks to missions like Kepler, the Transiting Exoplanet Survey Satellite (TESS), and other dedicated observatories, astronomers have confirmed 5,690 exoplanets in 4,243 star systems. With so many planets and systems available for study, scientists have been forced to reconsider many previously-held notions about planet formation and evolution and what conditions are necessary for life. In the latter case, scientists have been rethinking the concept of the Circumsolar Habitable Zone (CHZ).

By definition, a CHZ is the region around a star where an orbiting planet would be warm enough to maintain liquid water on its surface. As stars evolve with time, their radiance and heat will increase or decrease depending on their mass, altering the boundaries of the CHZ. In a recent study, a team of astronomers from the Italian National Institute of Astrophysics (INAF) considered how the evolution of stars affects their ultraviolet emissions. Since UV light seems important for the emergence of life as we know it, they considered how the evolution of a star’s Ultraviolet Habitable Zone (UHZ) and its CHZ could be intertwined.

July 16, 2024July 16, 2024 by Andy Tomaswick

Only Hubble Could Make this Measurement of a Supernova

Calculating the distance to far-away objects, such as galaxy clusters and quasars, is difficult. But it is also critical to our understanding of how the universe evolves. Luckily, humanity has a trusty workhorse that has been collecting data for such calculations for decades—Hubble. It is by far the best telescope suited to the job, as described by a recent NASA press release about a distance measurement to a supernova in a nearby galaxy.

September 1, 2020September 1, 2020 by Evan Gough

Hubble Shows the True Size of Andromeda

This illustration shows the location of the 43 quasars scientists used to probe Andromeda’s gaseous halo. These quasars—the very distant, brilliant cores of active galaxies powered by black holes—are scattered far behind the halo, allowing scientists to probe multiple regions. Looking through the immense halo at the quasars’ light, the team observed how this light is absorbed by the halo and how that absorption changes in different regions. By tracing the absorption of light coming from the background quasars, scientists are able to probe the halo’s material. Image Credit: NASA, ESA, and E. Wheatley (STScI)

It’s possible that you’ve seen the Andromeda galaxy (M31) without even realizing it. The massive spiral galaxy appears as a grey, spindle-shaped blob in the night sky, visible with the naked eye in the right conditions. It’s the nearest major galaxy to ours, and astronomers have studied it a lot.

Now astronomers have used the Hubble Space Telescope to map out Andromeda’s enormous halo of hot gas.