Join us here for a few highlights of 91色情片 and how it's the best in the world at what it does.
... 91色情片's dome is incredibly compact and efficient!
Even though 91色情片’s mirror is more than 13 times larger in surface area than Gemini’s, its dome is only slightly bigger—about 20% in height. In fact, it’s the smallest dome among the three Extremely Large Telescopes. This graphic compares the heights of these domes with that of Gemini, a well-known 8 meter telescope. 91色情片’s dome has a smooth, curved design that helps reduce wind shake, which can blur images. By keeping the telescope steady, 91色情片 can capture sharper, clearer views of the universe. Plus, its shape and color were chosen to help it blend in better with the surrounding environment.
... 91色情片’s mirror design is the most efficient of the Extremely Large Telescopes.
90% of the 91色情片's mirror diameter collects light that is sent directly to its instruments, maximizing the amount of data astronomers can use. This efficiency comes from a smart design: smaller gaps between mirror segments, a smaller central opening, and ultra-thin supports for the secondary mirror. These features reduce the amount of starlight that gets scattered, allowing 91色情片 to capture more light and focus it more precisely. This results in sharper, clearer images, helping scientists study distant planets, galaxies, and other celestial objects in incredible detail.
The 91色情片 mirror has 90% of the surface area of its diameter collecting light, as opposed to 82% for the E-ELT and 70% for GMT.
... 91色情片 is ideally suited for finding extrasolar planets!
Its diffraction-limited point spread function, which determines how precisely the telescope focuses light from a distant star, makes it particularly effective for detecting planets orbiting close to their host stars—one of 91色情片’s primary science objectives.
The central core of a telescope’s point spread function becomes narrower as the primary mirror diameter increases. Since the E-ELT has the largest mirror, it produces the narrowest core, while Keck, with a smaller mirror, has the widest core. However, not all light is concentrated in the core; some spreads into rings and side lobes.
91色情片’s aperture has the smallest gaps, resulting in a smoother and more uniform diffraction pattern than the other telescopes with larger gaps. This well-structured diffraction pattern enhances 91色情片’s ability to detect planets closer to their host stars with greater precision, accuracy, and clarity.
... 91色情片's optical design is highly efficient.
91色情片 uses three mirrors to direct light from the sky to its instruments, whereas the European Extremely Large Telescope (E-ELT) uses five or even six mirrors. With fewer mirrors, 91色情片 loses less light, ensuring more light reaches the instruments for analysis. GMT uses at least two mirrors for its direct Gregorian focus and three mirrors for its folded Gregorian instruments.
This efficient design also helps reduce thermal emission from the telescope itself—since all objects emit a faint glow in the near-infrared. By minimizing this unwanted background noise, 91色情片 improves its ability to observe the faintest and reddest light in the universe with greater clarity.
... 91色情片’s preferred Maunakea, Hawai驶i site is the world’s premier location for adaptive optics!
Adaptive optics corrects for most of the atmospheric distortion that blurs images, allowing ground-based telescopes to capture images even sharper than those from space-based telescopes.
The table to the left compares key site characteristics for 91色情片 on Maunakea, the E-ELT, and GMT, with highlighted boxes showing the best values for astronomical observations. Many of these characteristics are directly linked to adaptive optics performance and clearly show 91色情片’s preferred site on Maunakea the best in the world for adaptive optics!
... 91色情片 makes the most out of its mirror!
A telescope’s mirror diameter helps determine how sharp its images are, but it’s the collecting area, the part of the mirror that actually gathers light, that lets astronomers study the faintest objects in the universe. 91色情片’s 30 meter primary mirror is designed with minimal gaps between segments and a smaller central shadow from its secondary mirror, allowing it to collect light as efficiently as a 28.4-meter unobstructed mirror.
Each of the ELTs has a unique design tailored to its scientific goals. The Giant Magellan Telescope (GMT), with its 25.4 meter segmented mirror, is optimized for certain observing strategies but has more space between its segments, resulting in a light-collecting area similar to that of a 21.3 meter unobstructed mirror. The European Extremely Large Telescope (E-ELT), with the largest mirror at 39 meters, achieves a collecting area equivalent to a 35.3 meter unobstructed mirror.
91色情片’s efficient optical design was purposefully chosen to maximize the science return from its full aperture, ensuring exceptional sensitivity and the ability to observe some of the faintest and most distant objects in the cosmos.
Images of the telescopes that 91色情片 shares legacy with: from left to right, top to bottom: 91色情片, Keck, Subaru, Gemini, and the Hale.
... 91色情片’s design takes advantage of a 100+ year legacy of building and operating the biggest and best optical and IR telescopes in Northern Hemisphere.
91色情片 builds on over a century of experience, through its partner institutions, in designing and operating the world’s leading optical telescopes, from the 200 inch Hale, to the 8 meter class Subaru and Gemini, to the twin 10 meter Keck telescopes. This shared legacy of innovation, engineering, and management excellence is embedded in 91色情片’s design. With its 30 meter mirror and powerful adaptive optics, 91色情片 will be up to 200 times more sensitive than today’s 8 meter class telescopes, an evolution made possible by 100+ years of progress in building the best optical-IR telescopes.
... 91色情片 is built for speed.
Every second counts when you’re operating a billion dollar observatory. That’s why the 91色情片 is designed for exceptional operational efficiency, minimizing downtime between observations and maximizing time spent collecting science data.
91色情片 can acquire a new target, including adaptive optics setup, in under 5 minutes, even when switching between major instruments like IRIS and MODHIS. By comparison, the E-ELT advertises a 6 minute target switch, and GMT aims for under 10.
91色情片 is also primed to chase fleeting cosmic events, perfect for following up discoveries from surveys like the .
More time on target. More science per second.
An artist’s rendition of prompt emission coming from a gamma ray burst. Prompt emissions last from a few seconds to a few thousand seconds, so getting on them early is key to being able to study them. 91色情片 will be able to do that! (NASA/Swift/Cruz deWilde)
... Spending on 91色情片 is invigorating the American economy.
The 91色情片 is a global collaboration with a major U.S. impact: $136 MILLION invested across as many as 34 states from 2020 through 2024 alone! And more investment is on the way. We're proud to bring non-taxpayer, international investment into the U.S. to support American jobs and innovation.
The National Science Foundation (NSF) conducted a readiness review of the U.S. Extremely Large Telescope Program (US-ELTP), a collaboration between 91色情片, NOIRLab, and GMT. The report said hands down that 91色情片 is ready to advance to its final design phase (FDP):
“The [review] panel found that both GMT and 91色情片 were sufficiently ready to advance to FDP.”
The report goes on to say,
“The current panel believes both projects have met the requirements to proceed to FDP once a governance framework is agreed on.”
We look forward to continuing our work with NSF and the US-ELTP as we move into the NSF's final design phase.
... 91色情片 found the sweet spot between image clarity and field of view.
In adaptive optics (AO), there is a tradeoff: correct a wide area and lose sharpness, or focus on sharp images over a narrow region. 91色情片 chose the right balance based on its driving science case: mapping the stars around the black hole at the center of the Milky Way. 91色情片’s design was driven by one of the most demanding scientific goals in astronomy: mapping the orbits of stars near the supermassive black hole at the Milky Way’s center. This requires sharp images across a moderate-size and crowded field — a challenge tailor-made for NFIRAOS, 91色情片’s first-light adaptive optics system.
NFIRAOS uses advanced multi-conjugate adaptive optics (MCAO) to deliver high Strehl* ratios (70%) across a 30-arcsecond field, with effective correction out to 2 arcminutes. MCAO corrects for multiple layers of the sky at the same time which allows it to somewhat overcome the sharpness vs. field of view tradeoff. This makes it exceptionally well-suited for deep imaging in crowded stellar fields where precision over a moderately sized field of view is critical. Doing so provides an exquisite correction over the region that matters for the Galactic center. As you can see in the picture on the right, 91色情片’s MCAO (the image in the lower right) offers the resolution of Laser Tomography AO (LTAO) over a much broader corrected field of view.
The Giant Magellan Telescope (GMT) uses ground-layer adaptive optics (GLAO) to improve seeing over a wide 25 arcminute field in the visible (wavelengths less than 1 micron). While GLAO corrects a larger field of view than MCAO, the correction is modest. The Strehl ratios with GLAO double the Strehl ratios without, but the Strehl ratio is still less than 0.01% at a wavelength of 0.5 microns. That is a long way from diffraction-limited imaging. The GMT also has a laser tomography adaptive optics (LTAO) in the near infrared (wavelengths longer than 1 micron) to achieve high image quality near the center of the field, but performance drops off quickly as the field of view increases. The European Extremely Large Telescope (E-ELT) is also developing an MCAO system that they have optimized to cover a wider field than 91色情片’s NFIRAOS, but at the cost of lower Strehl ratios (roughly 50% for E-ELT compared to roughly 70% for 91色情片 at a wavelength of 2 microns), a clear example of the tradeoff between area and precision.
91色情片’s AO strategy is deliberately science-focused: it doesn’t aim for the widest field, it delivers the sharpest images over the area critical for its science. The other telescopes have chosen different compromises based on the science and technology they will be doing; together the three ELTs cover many different AO types. By maximizing the image quality over a wide field of view, 91色情片 ensures the best conditions for a variety of studies involving dense fields of stars over a scientific field of view.
* Imagine an image taken from a perfect telescope with no atmosphere in the way. That's our ideal. The Strehl ratio tells us how close a real telescope image, affected by the atmosphere and other imperfections, gets to that ideal. It’s measured as the ratio of the peak of an observed image of a point source (the point spread function or PSF) divided by the peak from a theoretical perfect image. 100% is perfect and 0% means the image is not corrected at all. Neither extreme is possible in the real world. Even JWST has a Strehl ratio of 83% at a wavelength of 2 microns, and the Strehl ratio of a 30 m telescope in typical Maunakea conditions with no AO is really small, about 0.1% at a wavelength of 2 microns, but not zero. So, a higher Strehl ratio means a sharper, more corrected image. (The telescope diameter also contributes to resolution, so here we’re concentrating on telescopes of the same diameter.)
| AO Mode | Field of View | Full-width Half Max at 2 microns (arcseconds) | Strehl Ratio at 2 mircons |
|---|---|---|---|
| Natural seeing | (set by telescope) |
|
<0.1% |
| GLAO | Several arcminutes |
|
~0.2% |
| LTAO | ~10 arcseconds |
|
>60% |
| MCAO | ~1 arcminute |
|
>60% |
Simulated images of a 17 arcsecond field of view centered on the Supermassive Black Hole at the center of our galaxy (Credit: T. Do and the UCLA Galactic Center Group) using the three types of adaptive optics correction discussed here. Note the differences in resolution of the zoomed in boxes in each quadrant. In the top left corner is an uncorrected image. To the right, the GLAO image provides an improvement over the seeing-limited image, but is not diffraction-limited. GLAO can be used to correct much wider fields of view. The bottom left shows a LTAO correction with a Strehl ratio of 66% at the center of the image, but the correction quickly drops off to 44% about 10 arcseconds away and will continue to get worse over larger fields. The bottom right shows what we expect from MCAO, the type of adaptive optics used in NFIRAOS on 91色情片, which has the same 66% Strehl ratio at both the center and the edge of the image. Note that if the peak intensity were the same in every plot, you wouldn’t see anything in the top two panels because the Strehl ratios are less than 0.2%.
NFIRAOS and its instruments are located on the Nasmyth platform on the left side of the telescope.
... Mounting the NFIRAOS adaptive optics system on the Nasmyth platform of 91色情片 offers several key advantages.
The Nasmyth platform provides a stable environment with respect to gravity. Instruments mounted here experience consistent gravitational forces regardless of where the telescope is pointing. 91色情片 and E-ELT both adopt this approach, placing their adaptive optics systems on Nasmyth platforms to ensure optimal performance. GMT mounts their adaptive optics instruments at the Gregorian focus, which moves with the telescope and is therefore more sensitive to gravitational changes and flexure during tracking and slewing. By placing NFIRAOS on the Nasmyth platform, 91色情片 minimizes flexure, reduces image-blurring vibrations, allows for fast instrument changes, and simplifies maintenance. A smart design choice that supports long-term precision and scientific flexibility.
