All-seeing telescope will snap exploding stars, may spy a hidden world
science.org
science.org
> Instead of looking out from a dome’s surface, the Argus telescopes will sit in a 10-meter-wide bowl, all aiming out a single skylightlike window in a dome.
Looks like photoreceptor cells in the retina of an eye all aimed up at the iris.
Here's links to the tech summary, and the overview paper, which reviews work presented at the just-concluded SPIE conference:
https://evryscope.astro.unc.edu/the-argus-array/ https://arxiv.org/pdf/2207.14318.pdf
The array (both prototype and projected final) is made from ~20cm telescopes. Such a telescope can't see very deep, so they are relying on co-adding across various temporal windows, up to 5 nights, to get to targets down to M = 23.6. Controlling the systematic effects (temperature, structural geometry, optical path) for a ground-based telescope across these time scales and equipment differences will be a challenge.
One very large facility (like this one, not yet built) in this space is Vera Rubin Observatory (https://www.lsst.org/about, formerly LSST). Rubin has much more glass, so it will see deeper, but its revisit time seems to be less frequent (once every 3 days), and it may not offer the real-time mode that this concept does.
A final observation: The funding for this concept comes from an NSF mid-scale innovations program (MSIP, https://beta.nsf.gov/funding/opportunities/mid-scale-innovat...). MSIP supports up to $30M-cost projects.
This is the same order of magnitude as support for renovating Arecibo was expected to cost, before that telescope failed. (https://www.science.org/content/article/astronomers-relieved... -- it appears the failure could have been avoided with better monitoring.) I'm just noting that to fund new stuff like this, the NSF does have to progressively retreat from older observatories.
I assumed the entire visible night sky included the Southern Hemisphere. But the diagram shows all the telescopes in one location.
> the Argus telescopes will sit in a 10-meter-wide bowl, all aiming out a single skylightlike window in a dome. Over the course of the night, the bowl and telescopes will pivot slowly to follow the stars as Earth rotates.
Huh, I was imagining telescopes watching the entire sky simultaneously. This sounds like it will see just a tiny part at a time. So a star could go nova and the system would only catch it if it happened to be facing the right part of the sky at exactly the right moment.
And you can't have it all. I had assumed atmospheric path length would be a problem as the FOV extends toward the horizon, but other optical issues limit you before that. From the arXiv paper I linked nearby:
> Angle-of-incidence effects: Commercially-available antireflection coatings have a restricted range of effective angles of incidence, and this places an effective upper limit of 100◦–120◦ on the field of view of an array looking though a single window. The Argus Array’s Key Projects’ requirements easily conform to these limits, especially with the acceptance of slightly increased light losses for telescopes at the edge of the array.
In other words, our FOV is about 90 degrees wide, and the coatings are OK to 100-120 degrees.
You buy a telescope that meets certain requirements. You connect to the system. Whenever you aren't using it, the system is directing it as to where to look, and the imagery is transferred to the centralized service, where it's stitched together and processed.
I'll bet you could find enough universities, organizations, and enthusiastic amateurs to join such a system.