Analysis and Comparison of the State-of-Art Telescopes:

Evidence from JWST, EHT and FGST

Yuxuan Hong

Ranney School, New Jersey, U.S.A.

Keywords: Telescope, EHT, JWST, FGST.

Abstract: As a matter of fact, the telescope has been a crucial tool in advancing astronomical knowledge since its

invention in the early 17th century. From Hans Lippershey's initial patents to Galileo Galilei's improvements,

the telescope has undergone a substantial evolution, reaching its current state as a sophisticated and innovative

instrument. These developments have facilitated a more profound comprehension of the universe, enabling

the observation of galaxies, stars, and planets, and have also propelled the investigation of dark matter and

energy. This paper examines the significant contributions and prospects of three advanced telescopes: the

James Webb Space Telescope (JWST), the Event Horizon Telescope (EHT), and the Fermi Gamma-ray Space

Telescope (FGST). Through a comparative analysis of their research outcomes and technical specifications,

this study elucidates their role in contemporary astronomical research. Furthermore, this research discusses

the current challenges and the potential for future innovations that will continue to advance the understanding

of the universe.

1. INTRODUCTION

The telescope has been a seminal instrument in

advancing astronomical knowledge since its

inception in the early 17th century. In 1608, Hans

Lippershey, a Dutch eyeglass maker, submitted a

patent to the Dutch Parliament, which, at the time,

was the highest authority in the country. Therefore,

Lippershey is considered the first to invent the

telescope. However, the Dutch Parliament should

have regarded as Hans's knowledge of the device.

Subsequent reports from that period were

disseminated, and in 1609, the Italian scientist Galileo

Galilei implemented structural modifications to the

telescope based on Hans Lippershey's account.

Galileo constructed his initial telescope

(subsequently designated the "Galilean telescope")

with a convex objective lens and a concave eyepiece.

He utilized this instrument to conduct a substantial

number of astronomical observations. Such

observations included the discovery that Venus

revolves around the Sun. This challenged the

geocentric model and supported the heliocentric

https://orcid.org/0009-0007-9858-8525

theory proposed by Nicolaus Copernicus. These

findings laid the foundation for modern astronomy.

The design and capabilities of telescopes have

undergone significant evolutions over the years.

These evolutions have encompassed a range of

innovations, from the simple refracting telescope

used by Galileo to the reflecting telescope invented

by Isaac Newton and on to the space telescopes. All

these innovations have greatly enriched mankind's

understanding of the universe. The successful

launches of the HST and the JWST have further

advanced the frontiers of astronomical research.

Telescopes are essential in basic astronomical

research, helping scientists observe and study

galaxies, stars, and planets and making significant

contributions to exploring the origin of the universe,

dark matter, and dark energy, among other areas. For

example, observations from the HST have helped to

confirm the accelerated expansion of the universe. At

the same time, the JWST has excellent performance

in infrared observations and is capable of capturing

information about the more distant and earlier

universe.

In recent years, significant advancements have

been made in the field of telescopes. Notable among

300

Hong, Y.

Analysis and Comparison of the State-of-Art Telescopes: Evidence from JWST, EHT and FGST.

DOI: 10.5220/0013075400004601

Paper published under CC license (CC BY-NC-ND 4.0)

In Proceedings of the 1st International Conference on Innovations in Applied Mathematics, Physics and Astronomy (IAMPA 2024), pages 300-306

ISBN: 978-989-758-722-1

these are the JWST, the EHT, and the FGST, which

may be considered the three most representative

advanced telescopes. The JWST was successfully

launched in 2021 (Dicken et al., 2024). The JWST's

primary strengths lie in infrared astronomy. Due to its

considerable dimensions, the JWST is equipped with

instruments of exceptional sensitivity and resolution,

enabling astronomers to study the initial galaxies and

stars in the universe, thereby providing further ideas

into the formation and evolution of the universe

(

Crompvoets et al., 2023). The telescope's achievements

extend beyond the observation of the formation of

stars and galaxies. Its contributions to the

understanding of phenomena, such as the formation

of the universe, are also significant. The EHT is a

network of multiple radio telescopes worldwide

(

Akiyama et al., 2021a). It is a global network of radio

observatories or radio telescope facilities that enables

high-resolution observations using Very-long-

baseline Interferometry (VLBI). The underlying

principle is to utilize a multitude of radio antennas in

a phased array configuration, thereby achieving a

larger effective aperture and enhanced angular

resolution. In 2019, the EHT achieved the first-ever

capture of a black hole event horizon, measuring it at

a wavelength of 1.3 millimeters and attaining a

theoretical diffraction-limited resolution of 25

microarcseconds. The black hole is situated at the

core of Messier 87 and is designated M87* (Patel et

al., 2022). This achievement has been celebrated as a

significant advancement in astronomical research,

significantly enhancing the understanding of black

holes and their environment. Moreover, it constituted

a test of Einstein's general theory of relativity. FGST,

previously designated the Gamma-ray Large Area

Space Telescope (GLAST), is a space-based

observatory designed to study high-energy gamma

rays. The spacecraft was successfully launched in

June 2008 and was named in honor of the renowned

physicist Enrico Fermi. It is a space observatory

whose principal function is the observation of gamma

rays in low Earth orbit. The observatory houses two

principal instruments: the Large Area Telescope

(LAT), which is used to study active galactic nuclei,

pulsars, and dark matter, and the Gamma-ray Burst

Monitor (GBM), which is employed to examine

gamma-ray bursts and solar flares.

As a fundamental instrument in astronomical

research, telescope technology's ongoing

advancement and implementation plays a pivotal role

in propelling scientific progress. The objective of this

paper is to examine the significant contributions and

prospective avenues of advancement of the three

cutting-edge telescopes (JWST, EHT, and FGST) in

contemporary astronomical research. This will be

achieved through a comparative analysis of their

research outcomes and technical specifications.

Additionally, the paper will present a comprehensive

overview of the telescopes and discuss the constraints

inherent to existing telescopes. The rest part is

organized as follows. Sec. 2 gives an introduction to

the definition, classification, development, and

number of telescopes. Sec. 3 focuses on the JWST,

focusing on its use, principles, instruments, and

recent results. Sec. 4 presents a detailed examination

of the EHT, encompassing its applications,

underlying principles, instrumentation, and recent

outcomes. Sec. 5 presents a detailed examination of

the FGST, encompassing its applications, underlying

principles, instrumentation, and recent outcomes.

Sec. 6 shows an examination of the constraints of

contemporary telescopes and proposals for future

developments. A brief summary is given in Sec. 7.

2 DESCRIPTION OF TELESCOPE

Telescopes are defined as devices that detect distant

objects by emitting, absorbing, or reflecting

electromagnetic radiation from them. The

fundamental concept is to utilize a lens or reflector to

collect and focus electromagnetic radiation, thereby

creating an enlarged image that enables the human

eye or other detectors to observe greater detail. The

visible light band does not constrain telescopes, but

rather, they encompass the entirety of the

electromagnetic spectrum, extending from radio

waves to gamma rays. The term "telescope" was first

used by the Greek mathematician Giovanni

Demisiani in 1611 to describe an instrument that was

subsequently provided to Galileo. The word "tele" is

derived from the Greek word for "far," while

"skopein" means "to see." Thus, the term "teleskopos"

can be translated as "to see far."

Telescopes can be classified according to three

primary criteria: their working principle, observing

bands, and intended use. Refracting telescope

employs a lens as an objective lens to refract light,

thereby forming an image. This particular telescope

design enjoyed considerable popularity during the

late 19th century, but is now more commonly

employed in other optical devices, including

binoculars and telephoto lenses. Reflecting telescope

employs a combination of single or multiple curved

mirrors to reflect light and form an image. The

inaugural reflecting telescope was devised by Isaac

Newton in the 17th century; however, it was still

imperfect and generated optical aberrations. The HST

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301

employs this technique. Catadioptric Telescopes

integrates the principles of refraction and reflection

with lenses and mirrors that function in conjunction

to reduce aberration and chromatic aberration and

enhance image quality.

The classifications according to the observation

wavelength is as follows. Optical telescope collects

and gathers light from the visible part of the

electromagnetic spectrum. Three methods are

employed to generate images: refraction, reflection,

and retroreflection. Radio telescopes are employed to

observe radio waves, with large dish antennas

typically utilized to collect and focus radio wave

signals. These devices possess a single receiver,

which can record a single signal. Infrared detectors

and cooling systems can be employed to observe the

infrared band and reduce thermal noise. All celestial

objects have a temperature are observed to emit

electromagnetic radiation. Ultraviolet telescopes are

used to observe in the ultraviolet band, and they must

be operated in space since most of the ultraviolet light

is absorbed by the atmosphere. X-ray telescopes are

used to observe the X-ray band, employing special

mirrors and detectors to focus and detect high-energy

X-rays. Gamma-ray telescopes are used to observe

the gamma-ray spectrum, and they utilize coded

aperture masks to generate images. They are typically

mounted in Earth orbit.

According to the usage location, they can be

categories as follows. Ground-based telescopes are

mounted on the Earth's surface. They typically have

large-aperture mirrors and advanced observing

techniques, as well as advanced optical systems for

data acquisition and analysis. They are less expensive

than space-based telescopes and can be easily

upgraded and maintained, such as the European

Southern Observatory (ESO) in Chile. Challenges

include atmospheric interference and limited

observations due to weather or seasons. Space-based

telescopes are installed outside the Earth's

atmosphere, such as the HST and the JWST. The

advantages are that there is no Earth's atmosphere to

interfere with the instrument's camera, it has a very

stable window, and different wavelengths can be

detected by different telescopes. The disadvantages

are that space telescopes are expensive to launch and

build, and have a very short lifetime. Space telescopes

are difficult to maintain and upgrade compared to

ground-based telescopes.

The technology and applications of telescopes

have continued to develop and expand, and since the

mid-20th century, advances in electronics and

computer technology have greatly increased the

power and resolution of telescopes. Computers can

help people make simulations and predictions.

Modern optical telescopes have evolved to use

adaptive optics, astigmatism, and optical

interferometry to overcome atmospheric disturbances

and greatly improve image resolution. Large ground-

based optical telescopes such as the Keck Telescope

and the Very Large Telescope are representative.

Radio telescope arrays such as the VLA in the United

States and the FAST in China are among the

telescopes. They have achieved significant results in

the search for dark matter and black holes. The JWST

is the most advanced infrared space telescope

available and will advance the study of the early

universe and galaxy formation; the Nancy Grace-

Roman Space Telescope, to be launched around 2027,

will be in a Sun-Earth L₂ orbit.

There are a number of ground-based and space-

based telescopes located around the world and in

space. Ground-based telescopes are mainly located in

areas that are less affected by the Earth's atmosphere

and less air pollution, such as Hawaii, the Atacama

Desert in Chile, and the Canary Islands. Space

telescopes are mainly located in Low Earth orbit or

deeper space, such as HST and JWST, which one is

in Low Earth orbit and one is in Sun-Earth L2 orbit.

According to statistics, there are 29 active space

telescopes and over 350 ground-based telescopes.

3 JAMES WEBB SPACE

TELESCOPE

JWST uses MIRI (Mid Infrared Instrument),

NIRCam (Near Infrared Camera), NIRISS (Near

Infrared Imager and Slitless Spectrograph) and

NIRSpec (Near Infrared Spectrograph) as imaging

methods. In wavelength range 0.6μm<λ<5μm,

NIRCam will be responsible for imaging by using

modes of parallel or primary. In wavelength range

0.8μm <λ<5μm, NIRISS will be responsible for

imaging by using modes of parallel or primary (Lau

et al. 2024). In wavelength range 5.6μm<λ<25.5μm,

NIRISS will be responsible for imaging by using

modes of parallel or primary. In wavelength range

0.6μm<λ<5.3μm, NIRSpec enables to analyze the

formation of galaxy and characteristics of stellar

populations (Whalen et al., 2012). MIRI’s FOV (field

of view) covers an area of 112.6” by 73.5”, which

covers wavelength from 5.6 to 25.5 μm. It has 9

broadband filters: F560W, F770W, F1000W,

F1130W, F1280W, F1500W, F1800W, F2100W,

F2550W (seen from Table 1).

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Table 1: All MIRI broadband filters are broadband

(λ/Δλ ~ 5) except F1130W, which isolates the 11.3μm

PAH emission feature (λ/Δλ ~ 16) explicitly.

Filter Name λ0 (

m) Feature(s)

F560W 5.6 Broadband Imaging

F770W 7.7 PAH, broadband imaging

F1000W 10 Silicate, broadband imaging

F1130W 11.3 PAH

F1280W 12.8 Broadband imaging

F1500W 15 Broadband imaging

F1800W 18 Silicate, broadband imaging

F2100W 21 Broadband imaging

F2550W 25.5 Broadband imaging

NIRCam’s FOV covers a 9.7 arcmin2 with range

of 0.6 − 2.3 μm (0.031"/pix) and 2.4 −

5.0 μm (0.063"/pix) . It is separated into two

channels: short wavelength channel and long

wavelength channel. In short wavelength, its FOV is

2 × 2.2’× 2.2’ with 4” – 5” gaps and imaging pixels

can reach 8 × 2040 ×2040 pixels. Its long wavelength

channel’s FOV is 2 × 2.2’× 2.2’ and imaging pixels

can reach 2 × 2040 ×2040 pixels. These two channels

allow it to peer through dust clouds that obscure

visible light, revealing objects and phenomena that

are hidden from view. It has 4 observing modes,

which cover a wavelength range from 0.8 – 5 μm.

Those four observing modes are WFSS, SOSS, AMI,

and Imaging. WFSS has wavelength coverage of

0.8 − 2.2 μm with pixel scale of 0.066”/ pixel

(arcsec/pixel). It has a FOV of 133×133 arcsec. Its

resolving power (𝑅 = 𝜆 ⁄ 𝛥𝜆) is 150 @ 1.4 μm.

SOSS has wavelength coverage of 0.6 − 2.8 μm with

pixel scale of 0.066"/pixel (arcsec/pixel). It uses a R

= λ/Δλ = 700 grism to disperse the light from the

target object into its constituent wavelengths without

the use of a slit. AMI has the highest spatial resolution

imaging which employs a mask with 7 small holes or

sub-apertures and turns the full aperture of JWST into

a interferometric array to analyze to reconstruct high-

resolution images. Its FOV is 5.2 × 5.2 arcsec with

pixel scale of 0.066” / pixel. Imaging mode allows

NIRISS to capture high-resolution images in the near-

infrared spectrum from wavelength range of 0.8 – 5

μm. Since NIRISS has 12 filters (except F158M),

NIRCam has correspond filter which can help

imaging. When NIRISS and NIRCam work at same

time for imaging, NIRISS will become the third

channel for NIRCam including long wavelength

channel and short wavelength channel. It designs to

perform spectroscopy in the near-infrared spectrum

from 0.6 − 5.3 μm within a 3.4 × 3.6 arcmin FOV,

using MSA, IFU, and FSs. Each observing mode have

different aperture or slit size (arcsec): MSA has

aperture of 0.20 × 0.46; IFU has aperture of 3.0 × 3.0;

FSs has three size 0.2 × 3.2, 0.4 × 3.65, 1.6 × 1.6; and

BOTS has aperture of 1.6 × 1.6. Their wavelength

coverage including range can also be separated into

five parts: 0.6-5.3 μm (prism), 0.7-1.27 μm (f070lp),

0.97-1.89 μm (f100lp) , 1.66-3.17 μm (f170lp) and

2.87-5.27 μm (f295lp).

The JWST is comprised of three primary

components: the spacecraft bus and sun shield, the

OTE, and the ISIM. The JWST is divided into two

sections: a 300K section facing the Sun and a 40K

section facing away from the Sun. The sun shield is

employed to safeguard the OTE and ISIM from solar

radiation, thus preventing overheating of the

equipment. Due to its capacity to permit only 1W of

heat transfer, the shield is capable of maintaining the

essential components of the telescope at the requisite

low temperatures without the use of consumable

refrigerants. This is made possible by its distinctive

five-layer polyimide film (such as Kapton), with each

layer coated with a reflective material to minimize

heat transfer. Each layer is approximately 21 meters

long and 14 meters wide.

In September 2023, the JWST identified the

presence of carbon-based molecules in the

atmosphere of the exoplanet K2-18 b, which is

hypothesized to possess an ocean. Prior research and

observations conducted with the HST have indicated

that the planet may be a "Hycean" world,

characterized by the presence of liquid water, which

is an essential component of life. K2-18 b has a radius

that is two to three times that of the Earth and is

situated approximately 120 light-years from the solar

system. The planet has a mass approximately 8.6

times that of Earth and is situated within the habitable

zone of its star, indicating that this region is neither

excessively hot nor cold. The most recent findings

indicate the presence of carbon dioxide and methane

in the atmosphere of K2-18 b, yet no ammonia has

been detected. This could be indicative of the

existence of a water-rich ocean beneath the hydrogen-

dominated atmosphere. This could contribute to the

understanding of the atmospheric and environmental

conditions of sub-Neptunian and Hycean worlds.

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4 THE EVENT HORIZON

TELESCOPE

The EHT is a globally distributed network of radio

telescopes that employs a technique called Very Long

Baseline Interferometry (VLBI). This technique

enables the network to achieve extremely high

angular resolution by combining multiple long-range

radio telescopes to form an Earth-sized virtual

telescope. VLBI is a technique for observing the same

object by synchronizing radio telescopes situated at

disparate locations. The resolution of the system is

directly proportional to the baseline distance between

the telescopes (Zhang et al., 2024). Each telescope

collects and records a substantial quantity of radio

data (Psaltis, 2019). To guarantee the accuracy of the

data, an atomic clock, is utilized to provide an

accurate time reference. The data are transmitted to a

data center via a high-speed data chain, where the two

data sets are compared and multiplied by the speed of

light, thereby yielding the geometric distance along

the line of sight to the quasar. More precisely, the

VLBI can be considered to be a radio interferometer.

Two antennas are oriented towards the same location

in the sky, with the signal emitted by antenna 1 being

at a distance of τg greater than that of antenna 2. The

two signals are then multiplied together and averaged

into a correlator, which results in a complex number,

denoted phase by 2π𝜏𝑔𝑐/𝜆. Here, λ is the wavelength

of the received radio waves and c is the speed of light.

However, the resulting phase would be exceedingly

large. To reduce the phase to zero, it is sufficient to

introduce a compensating delay τg at the second

antenna, thereby enabling the array to alter its

orientation with respect to the target source in the sky,

despite the Earth's rotation. For HT, the radio

antennas are separated by considerable geographic

distances. These include the ALMA, APEX, the

IRAM 30-meter telescope, the JCMT, and the LMT.

These include the SMA, SMT, SPT, the Greenland

Telescope, the NOEMA in France, and the Arizona

ARO 12-meter Telescope at Kitt Peak. The EHT's

VLBI is now capable of observing at a wavelength of

1.3 millimeters, representing the shortest wavelength

currently available. At each site, it records radio

waves at a rate of 64 gigabits per second.

Image reconstruction is the process of converting

processed radio data into a visual representation. As

individual telescope observations are frequently

incomplete and noisy, image reconstruction

necessitates the application of sophisticated

algorithms and models to fill data gaps and remove

noise. This motivates the use of principal-component

interferometric modeling (PRIMO), which is trained

on a large number of accretion black hole simulation

images (

Akiyama et al., 2021a; Akiyama et al., 2021b).

This approach employs principal components

analysis (PCA) to achieve high-fidelity general

relativistic magnetohydrodynamic (GRMHD) results.

Subsequently, the data are subjected to analysis

employing the Markov Chain Monte Carlo (MCMC)

PCA components of the Fourier transform of the

linear combination space. A sketch is shown in Fig.

Figure 1: The image on the far left depicts EHT's data

from 2017, the image in the middle represents the

result of reconstructing the image after PRIMO, and

the image on the far right is a combination of the two.

It is evident that the resolution has increased

significantly, and the diameter and bezel width have

decreased (

Akiyama et al., 2021a).

Since its inception, the EHT has yielded a number

of significant scientific findings, particularly in the

domain of supermassive black holes. The initial

outcome was the dissemination of the inaugural

image of the black hole situated at the nucleus of the

M87 galaxy. In April 2019, the EHT team published

the first photograph of a black hole, marking a

significant milestone in the history of astronomy. The

black hole is situated within the galaxy M87,

approximately 55 million light-years from Earth. In

the image, a bright ring-like structure with a dark

central region is evident, which is believed to

represent the event horizon of the black hole. This

validated Einstein's theory of general relativity and

furnished insights into the genesis and dynamics of

black hole jets. In 2023, the EHT released a new

image of the M87 black hole, created using the

PRIMO algorithm. The second result was an image of

Sagittarius A*, a black hole at the center of the Milky

Way (Medeiros et al., 2023). The image is of

markedly greater clarity, and the black hole is

observed to exhibit reduced activity, with an

accretion rate that is similarly low. The results

provide data regarding the event horizon of black

holes, the material in their vicinity, and the effects of

these phenomena.

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5 THE FERMI GAMMA-RAY

SPACE TELESCOPE

The imaging methodology employed by the Fermi

telescope is contingent upon the capabilities of its two

principal instruments: the Large Area Telescope

(LAT) and the Gamma-ray Burst Monitor (GBM).

The Large Area Telescope is responsible for the

capture and imaging of gamma rays from the

universe. It covers the energy range from about 20

MeV to more than 500 GeV, with a FOV of about 2.4

steradians. The process is comprised of four distinct

steps: gamma-ray detection, energy measurement,

orientation reconstruction, and image reconstruction.

Gamma rays interact with the telescope material,

creating electron-positron pairs that are detected by

LAT silicon microstrip detectors and trackers

(Thompson, 2022). Subsequently, the calorimeter

below measures the energy of these particles and

records the data. Following the collection and

subsequent software analysis of the gamma-ray

events, the data is converted into images of the

objects in order to facilitate their visualization. The

GBM represents the second principal instrument of

the FGST for the detection and study of GRBs. The

instrument is comprised of 14 scintillation detectors,

12 sodium iodide crystals (Nal), and two bismuth

germanate crystals (BGO), which collectively cover

the 10 keV - 40 MeV energy range. This also

guarantees that the FGST is capable of continuous

operation, always monitoring the sky and detecting

GRBs in a prompt manner. Moreover, the GBM can

measure the energy spectrum of gamma-ray bursts,

thereby confirming the energy distribution and

process of these bursts.

Although the FGST is still operational, it has

exceeded its design lifespan and has yielded

significant scientific insights in the field of

astrophysics. LAT observations have found

thousands of gamma-ray sources, including stars,

galaxies, and explosions. Additionally, the GBM has

detected a considerable number of gamma-ray bursts,

yielding a substantial corpus of data. The FGST has

fulfilled its intended purpose. Furthermore, the FGST

has detected gamma-ray signals from dark matter and

observed high-energy gamma rays. These

observations provide a crucial scientific foundation

for understanding the most extreme physical

processes in the universe.

6 LIMITATIONS AND

PROSPECTS

A comparative analysis of the various telescopes

reveals that each is subject to inherent limitations. For

instance, the JWST is constrained by operational

temperature, field of view, and maintenance

requirements over its lifetime. The JWST relies

heavily on its sunshade and passive cooling system to

maintain its operation, as extremely low temperatures

are required to prevent the infrared (IR) detector from

being affected by thermal radiation. Secondly, the

JWST has a relatively narrow field of view, which

restricts its ability to observe a comprehensive area

simultaneously. If observations are to be made over a

large area of the sky, it is necessary to undertake

multiple observations, which are then spliced

together. This approach compromises both efficiency

and accuracy. Additionally, the JWST is situated at a

considerable distance from Earth, which will render

repairs to the telescope a challenging undertaking in

comparison to the Hubble telescope. The EHT is

constrained by the diameter of the Earth,

meteorological conditions, and the intricacy of the

data. Although the EHT's VLBI technology is highly

sophisticated, its largest span is the diameter of the

Earth, which represents the only viable means of

observing the target star. This renders observation of

certain minute or remote objects unfeasible.

Secondly, the EHT necessitates favorable

meteorological conditions across multiple regions

simultaneously, which is not a reliable or consistent

occurrence. In addition, the EHT requires the

processing of highly intricate data, which results in

the generation and analysis of images that are time-

consuming and laborious. Furthermore, the FGST is

constrained by limitations in energy range and

resolution. Its energy range extends from 20 MeV to

500 GeV, and it cannot observe gamma rays at either

lower or higher energies. Secondly, the spatial and

temporal resolutions of the FGST and LAT are

insufficient for observing subtle variations in

phenomena with efficiency.

The future of telescopes will likely involve

coordinated observations across multiple wavelength

bands and an increased demand for high-resolution

and sensitive instruments. By simultaneously

observing data in different bands, the telescope will

facilitate a more comprehensive understanding of the

physical properties of celestial objects and enable the

revelation of details that cannot be observed in a

single band. The resolution and sensitivity of a

telescope are the primary determinants of its

observational capability. The forthcoming generation

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of telescopes, exemplified by the WFIRST, will

possess enhanced resolution and sensitivity, thereby

facilitating more comprehensive investigations of the

early universe and the center of the Milky Way.

7 CONCLUSIONS

The telescope has been a vital tool in the advancement

of astronomical knowledge since it was invented in

the early 17th century. The technology and

capabilities of telescopes have changed a lot over

time. Modern telescopes, such as the JWST, the EHT,

and the FGST, represent the cutting edge of

astronomical research today. The main strength of the

JWST lies in infrared astronomy, where its high

sensitivity and resolution allow it to study the initial

galaxies and stars in the universe. The EHT with

VLBI has captured an image of the black hole at the

center of the Galaxy M87. The FGST studies high-

energy gamma rays and other phenomena. The

successful launches and observations of these

telescopes have really moved the needle in

astronomy. They've helped scientists observe and

study galaxies, stars, planets, the origins of the

Universe, dark matter and dark energy, and more.

With further tech development, one will see even