Lazuli, the 3-meter observatory from the Eric and Wendy Schmidt Observatory System, is moving on a compressed schedule, and its planet-hunting instrument now has a first list of targets years before its planned launch.
In a paper posted to arXiv on October 22, Logan Pearce of the University of Michigan and Ewan Douglas of the University of Arizona name 27 known giant exoplanets as the opening targets for Lazuli's ExtraSolar Coronagraph, or ESC. The 31-page study, with 16 figures and two tables, has been submitted to the AAS Journals. It reads like a practical answer to a practical question: once a privately built telescope can block the light of a star, where should it look first?
A telescope from outside the usual pipeline
Lazuli belongs to the Eric and Wendy Schmidt Observatory System, a group of four new observatories: the Argus Array, the Deep Synoptic Array, LFAST and the Lazuli Space Observatory. Schmidt Sciences describes the program as built on rapid development cycles meant to cut timelines from decades to years, along with modular designs and open data and software available worldwide.
Universe Today calls Lazuli the first private space telescope and the scientific child of Eric Schmidt. Its primary mirror is 3 meters across, larger than Hubble's 2.4 meters, and the target is launch by 2029. It will carry three instruments: a wide-field optical imager, an integral field spectrograph and the ExtraSolar Coronagraph, which is designed to image gas giants in visible light by the starlight they reflect.
That last detail is what makes the target paper worth reading.
Reflected light versus glowing heat
Direct imaging of exoplanets has mostly favored one kind of world: young, hot giants that still glow with the heat of their formation. Planets that are older have had time to dim, so their leftover formation heat makes them harder to observe that way.
Reflected light gets around that problem. A planet that shines by the starlight bouncing off its clouds does not need to be young. Its reflected brightness does not fade with age the way leftover formation heat does. That is why Pearce and Douglas say their list covers ages and temperatures that direct imaging has not probed before. In Universe Today's coverage, the authors describe this as pushing direct imaging into colder regimes.
The catch: faint planets and long exposures
None of this is easy. The planets ESC is after are between about ten million and a billion times fainter than their host stars, contrasts of order 10-7 to 10-9. Detecting them can take tens to hundreds of hours of exposure time.
For a 3-meter-class observatory, that cost is decisive. A blind search, pointing the coronagraph at nearby stars and hoping something turns up, would spend huge amounts of telescope time with no guarantee of a result. So the paper starts with planets that are already known and have well-constrained orbits, which lets observers prioritize targets and time observations for the maximum likelihood of detection.
The result is a list built for efficiency: planets with well-known orbits, chosen to make the best use of observing time.
What is on the list
All 27 targets are giant planets, and only one orbits an M dwarf. Universe Today highlights several:
- 55 Cancri d, described as a Jupiter analog. Imaging a planet like this in reflected light would add a Jupiter analog to the list of directly observed worlds.
- HD 181433 d, which follows a highly eccentric orbit in a system that also hosts an ultra-short-period super-Earth. An eccentric orbit means the planet's distance from its star, and so its brightness in reflected light, changes a lot over time.
- Beta Pictoris b, one of the first exoplanets ever directly imaged, which orbits a young star with a well-known debris disk.
The authors also note that some targets are reachable by other facilities, including the Roman Space Telescope's coronagraph and the METIS instrument on the Extremely Large Telescope. The authors say this overlap could provide more comprehensive atmosphere characterization through synergies between the platforms.
Why It Matters
The scientific case is simple. Reflected-light imaging of mature giant planets fills a gap between what indirect detection methods tell us (orbits and masses) and what thermal direct imaging has shown (young, hot planets). Seeing older, colder giants in visible light opens the door to studying the atmospheres of mature planetary systems, which the authors say direct imaging has not probed before.
The institutional case may matter just as much, and Universe Today notes it remains to be seen how effective a privately owned telescope will be. Lazuli is a test of whether private money and fast, modular engineering can deliver a 3-meter observatory, larger than Hubble, on a schedule measured in years. A detailed, peer-review-bound target list from university researchers suggests the scientific planning is moving alongside the hardware.
Some caution is still warranted. The 2029 launch is a goal, not a guarantee, and the contrast levels involved leave little margin for error. Exposures of tens to hundreds of hours per target also mean ESC's campaign will take a long time even with a well-chosen list. But if the coronagraph performs as intended, the first private space telescope will start with a clear plan.
