Researchers name 27 giant exoplanets as targets for planned private Lazuli Space Telescope
A new target list for Lazuli's ExtraSolar Coronagraph focuses on known giant planets that could be imaged by the starlight they reflect.
Two astronomers have proposed 27 giant exoplanets as targets for a planet-imaging instrument on the Lazuli Space Telescope, according to Universe Today. The outlet describes Lazuli as the first private space telescope.
Universe Today reported that the telescope is backed by Eric Schmidt, Google's former CEO. It will have a 3-meter mirror, larger than Hubble's 2.4-meter mirror, and is due to launch by 2029. It will carry three instruments: a wide-field optical imager, an integral field spectrograph and the ExtraSolar Coronagraph (ESC).
The target list comes from a paper by Logan Pearce of the University of Michigan's Department of Astronomy and Ewan Douglas of the University of Arizona's Steward Observatory. It is available on arxiv.org.
The ESC is designed to study exoplanets and their atmospheres using the starlight they reflect, not the heat they give off. Universe Today explained that planets lose leftover heat from their formation as they age and grow dimmer, so reflected light makes it possible to study older systems. Working at visible wavelengths also lets the instrument look at planets orbiting closer to their stars.
"To date all exoplanets have been imaged through their self-luminous thermal emission, but direct, spatially resolved imaging of planets via reflected starlight is on the near horizon," the authors write.
The authors say this approach could also allow searches for biosignatures. They write that their list "spans ages and temperatures of planets not probed before by direct imaging." According to Universe Today, some of the targets will also be observable by the ELT's METIS thermal imager and by the coronagraphic instrument on the Nancy Grace Roman Space Telescope. The authors say combining those observations will "provide comprehensive atmosphere characterization."
The method has limits. The authors write that the high contrasts involved and "subsequent long exposure times (10s–100s of hours) make uninformed searches challenging for a 3m class observatory." That is why the list is built from planets whose orbits are already well known, so observing time can be scheduled when a detection is most likely. Universe Today reported that only one of the 27 host stars is an M-dwarf. It named Beta Pictoris b, one of the first directly imaged exoplanets, as one of the targets.
Some questions are still open. The telescope has not launched yet, and Universe Today noted that it remains to be seen how effective it will be. The outlet also said it is unclear what private ownership will mean for the project, and whether it will make the telescope more efficient, bring problems no one expected, or both.
This story rests on a single report from Universe Today, which summarizes the researchers' paper.
