Subj : James Webb targets detailed as commissioning nears completion To : All From : NasaSpaceFlight Date : Mon May 30 2022 21:15:04 James Webb targets detailed as commissioning nears completion Date: Mon, 30 May 2022 20:06:59 +0000 Description: Over the past five months, the James Webb Space Telescope and the joint NASA, European The post James Webb targets detailed as commissioning nears completion appeared first on NASASpaceFlight.com . FULL STORY ====================================================================== Over the past five months, the James Webb Space Telescope and the joint NASA, European Space Agency, and Canadian Space Agency teams behind the project have been working towards the completion of the observatorys six-month-long commissioning phase at the Sun-Earth Lagrange point 2 (L2). With the observatorys mirrors recently completing alignment, Webb and its teams are preparing for the all-important and historic first image from the observatory. As teams continue to work towards completing commissioning, some of the first scientific research targets of Webbs operational phase have been announced, including two strange and intriguing exoplanets that exhibit unique characteristics. After launching in December 2021 , the James Webb Space Telescope (JWST) successfully deployed its mirror assemblies and arrived on station at L2. It has since been undergoing checkout and commissioning operations ahead of beginning its science mission. Once Webb is finally ready for operations, it will release its first images which will be focused on bright stars. While Webbs first images will undoubtedly contain some data of scientific interest, their goal is not to investigate or research these stars. Instead, they will be used to confirm that Webb as a whole is performing as expected at L2 and that there are no issues with the observatorys complex optical systems. After confirming that all of the optical and structural systems are operating as planned, James Webbs commissioning phase will be complete and the observatory will assume operational status. Webb and its science teams have already lined up a plethora of research targets for the first few weeks of the observatorys operational phase, some of which may produce images as weve never seen before from other telescopes. Among the many research targets outlined for Webbs first few weeks of operation are two exoplanets that exhibit unique characteristics: 55 Cancri e and LHS 3844 b. 55 Cancri e and LHS 3488 b compared to Earth and Neptune. (Credit: NASA/ESA/CSA/Dani Player (STScI)) 55 Cancri e is an extremely hot super-Earth exoplanet located 41 light-years away in the constellation Cancer, where it orbits its Sun-like parent star 55 Cancri A. The exoplanet is around double the diameter of Earth and is around 8.63 Earth masses. At the time of its discovery in August 2004, it was the first super-Earth to be found. Orbiting just 1.5 million miles from 55 Cancri A, the exoplanet completes one orbit around its parent star in just 18 hours and is thought to feature oceans of lava on its dayside due to its extremely hot surface temperatures. See Also JWST Mission Updates Space Science coverage L2 Future Spacecraft Click here to Join L2 Whats more, 55 Cancri e is likely tidally locked due to its close proximity to 55 Cancri A. This would be expected to ensure that the parts of the surface facing the star most directly would be the hottest region of the planet. Telescope data from NASAs Spitzer Space Telescope, however, suggests otherwise showing that the exoplanets hottest region is offset from this position. Spitzer data also indicates that the total amount of heat on the dayside of the planet varies. So why is this? Why wouldnt the hottest region of 55 Cancri e be the region facing its parent star most directly? One of the leading theories behind the Spitzer observations is that 55 Cancri e may have a thick and dynamic atmosphere that moves heat around the planet from various regions. Another theory behind the occurrence could be that 55 Cancri e isnt actually tidally locked, and is instead more like Mercury: orbiting on its axis three times for every two orbits it completes around 55 Cancri A in what is called a 3:2 resonance. That could explain why the hottest part of the planet is shifted, explained Alexis Brandeker of Stockholm University when discussing the 3:2 resonance theory. Just like on Earth, it would take time for the surface to heat up. The hottest time of the day would be in the afternoon, not right at noon. Furthermore, the 3:2 resonance scenario would cause 55 Cancri es surface to heat up, melt, and vaporize into the exoplanets atmosphere. When the vapor eventually cools in the evening, it could condense and form droplets of lava that would subsequently rain onto the exoplanets surface. To truly determine the cause of 55 Cancri es heat distribution, Webb teams will use the observatorys Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) in different ways to test each theory. When testing the first theory involving a thick atmosphere, teams will use NIRCam and MIRI to view the thermal emission spectrum from the dayside. To test the second theory wherein the exoplanet isnt tidally locked, teams will use NIRCam to observe and measure the heat emitted from the dayside over four orbits, allowing teams to measure each hemisphere of the exoplanet twice if the exoplanet truly has a 3:2 resonance. This allows teams to observe whether there are any differences between the planets two hemispheres. 55 Cancri e could have a thick atmosphere dominated by oxygen or nitrogen. If it has an atmosphere, [Webb] has the sensitivity and wavelength range to detect it and determine what it is made of, explained Renyu Hu of NASAs Jet Propulsion Laboratory. Another research target for Webb is another extremely hot super-Earth exoplanet named LHS 3844 b. Located 49 light-years away orbiting red dwarf LHS 3488, LHS 3488 b like 55 Cancri e orbits extremely close to its parent star, completing one orbit around it in just 11 hours. LHS 3488 bs parent star is a red dwarf, meaning it is much cooler and smaller than Sun-like stars such as 55 Cancri A. Due to its parent stars small size, LHS 3488 b is not hot enough to have a molten surface like 55 Cancri e and Spitzer data suggests it likely does not have an atmosphere surrounding it. Artists impression of LHS 3488 b. (Credit: NASA/JPL-Caltech/R. Hurt (IPAC)) The lack of an atmosphere around LHS 3488 b gives scientists the chance to carry out a thorough examination of possible rock formations and other surface characteristics using telescopes. Although Webb is not capable of imaging the exoplanets surface directly, teams can use spectroscopy to study it. The team of scientists, led by Laura Kriedberg of the Max Planck Institute for Astronomy, will use MIRI to observe and measure the thermal emission spectrum of the dayside of LHS 3488 b. Once the team has captured the emission spectrum from the planet, they will compare it to the spectra of rocks such as basalt and granite to determine the composition of the exoplanets surface. It turns out that different types of rock have different spectra. You can see with your eyes that granite is lighter in color than basalt. There are similar differences in the infrared light that rocks give off, Kreidberg explained. They (the exoplanets) will give us fantastic new perspectives on Earth-like planets in general, helping us learn what the early Earth might have been like when it was hot like these planets are today. Webbs observations of 55 Cancri e and LHS 3488 b are part of the observatorys Cycle 1 General Observer program. Under the General Observers program, scientists can submit research targets for Webb to observe for their research. This same process is also used with the Hubble telescope to allocate time for scientists. (Lead image: Rendering of the James Webb Space Telescope. Credit: Mack Crawford for NSF/L2) The post James Webb targets detailed as commissioning nears completion appeared first on NASASpaceFlight.com . ====================================================================== Link to news story: https://www.nasaspaceflight.com/2022/05/james-webb-first-research-targets/ --- Mystic BBS v1.12 A47 (Linux/64) * Origin: tqwNet Science News (1337:1/100) .