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24 votes

"Next Generation Arecibo Telescope (NGAT)... would combine a 314-metre-wide platform with a swarm of 9-metre dishes on top" What would that look like?

There are a few diagrams in the original white paper (Anish Roshi et al. 2021; see Fig. 11) and the revised NGAT-130 proposal (Anish Roshi et al. 2023; see Fig. 3), depicting the basic arrangement. ...
HDE 226868's user avatar
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24 votes

Vera C. Rubin's LSST's ginormous camera's shutter; why does it open/close 1000 times a night & is this typical for large-format survey telescopes?

From Technology of the LSST focal plane: LSST’s survey efficiency depends on the telescope’s ability to rapidly move from field to field on the sky during a night’s observing. The mount has been ...
John Doty's user avatar
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17 votes
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Is this an image of an astronomical observatory? If not, what's behind these domes?

It is indeed an astronomical observatory: University of Canterbury Mt John Observatory, located atop Mount John in New Zealand. Coordinates 43°59'6.99"S 170°27'50.76"E if you want to look ...
Jean-Marie Prival's user avatar
16 votes
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Vera C. Rubin's LSST's ginormous camera's shutter; why does it open/close 1000 times a night & is this typical for large-format survey telescopes?

The "sequence" of a CCD exposure might be to flush the CCD to get rid of all charge on the silicon, with the shutter closed; open the shutter; expose the CCD to astronomical light; close the ...
ProfRob's user avatar
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9 votes
Accepted

Why does Helix Nebula look like an eye?

Look at Helix Nebula NGC 7293 (Aquarius) on the left and Ring Nebula M57 (Lyra) on the right. Both are of the planetary nebula type, and very similar. This NASA video, based on Hubble Space Telescope ...
Albert's user avatar
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6 votes

Impact of Atmospheric Water vapour on Optical Observations

There is actualy very little water vapour absorption in the optical part of the spectrum (350 - 750 nm). If "optical" is extended (as it often is) to include that part of the spectrum where ...
ProfRob's user avatar
  • 155k
6 votes

What telescope is Polish astronomer Kazimierz Kordylewski holding in this April 1964 photo at the Jagiellonian University Observatory in Krakow?

As a son of Kazimierz Kordylewski I lived with him in the 60s in the Krakow Observatory and I remember this telescope very well. It was called "luneta ekspedycyjna" and it was portable. To ...
Les's user avatar
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4 votes
Accepted

What are the technological advancements that made it possible for modern large telescopes to work with alt-az mounts instead of equatorial mounts?

I would say the field derotator was a great advancement. The field of view of an altazimuthally mounted instrument will rotate, just like for the naked eye—for example, the “Lady in the Moon” seems to ...
Pierre Paquette's user avatar
4 votes

Mauna Kea versus Mauna Loa: Astronomy ethical considerations

While some of these questions might be better suited for astronomy history SE, Ill give brief answers here and end in your astronomy question. There have been controversies and conflicts related to ...
Daddy Kropotkin's user avatar
3 votes

Why is plasma used to deposit aluminum on the VLT's four large mirrors?

As shown in an ESO image, the mirrors are coated in a giant plasma sputter system, where ions produced in a (presumably argon) plasma are accelerated and strike the pure aluminum, freeing neutral ...
Jon Custer's user avatar
3 votes

How are the Extremely Large and Thirty Meter Telescopes coming along ("planned 2027")

The ELT looks basically on track. It’s scheduled to start scientific observations in 2028 and is now half-completed. See https://www.eso.org/public/news/eso2310/ The TMT’s fate is less positive, ...
Pierre Paquette's user avatar
3 votes

What are the technological advancements that made it possible for modern large telescopes to work with alt-az mounts instead of equatorial mounts?

The equatorial mount is an analog computer that performs the transformation from local terrestrial coordinates to celestial coordinates. Building it into the structure of the telescope is necessary ...
John Doty's user avatar
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3 votes

Which University of Oklahoma research purported to "detect thousands of extragalactic planets back in 2018"? Which instrument was used?

The press release associated with the 2018 study is here; the actual article is Dai & Guerras (2018). From the abstract: Here, we show that quasar microlensing provides a means to probe ...
Peter Erwin's user avatar
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3 votes

Why does Helix Nebula look like an eye?

Prior to the formation of the Helix Nebula, there was a star similar to our own Sun in its post-main sequence stage. Eventually, this star consumed its entire fuel supply, which caused fusion to cease ...
4NT4R3S's user avatar
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2 votes

Vera C. Rubin's LSST's ginormous camera's shutter; why does it open/close 1000 times a night & is this typical for large-format survey telescopes?

why does it open and close a thousand times a night? The other answers, while correct and fascinating, are completely irrelevant. The CCD readout time is important to the designers, but irrelevant to ...
Miss_Understands's user avatar
2 votes

Vera C. Rubin's LSST's ginormous camera's shutter; why does it open/close 1000 times a night & is this typical for large-format survey telescopes?

Supplemental, re-explaining answer post for those like me who are not so familiar with CCDs. I find the video below very helpful. Of the five readout systems illustrated, the two relevant here are: ...
uhoh's user avatar
  • 30.7k
1 vote

What is the LSST now? Where does LSST end and Vera C. Rubin Observatory begin?

It's correct that the telescope formerly known as the Large Synoptic Survey Telescope (LSST) is now named the Vera C. Rubin Observatory. However, the acronym LSST has indeed been repurposed and now ...
vivek's user avatar
  • 106

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