Telescopes of the world

CLASS

Cosmology Large Angular Scale Surveyor

It is an array of four microwave telescopes at a high-altitude site in Chile's Atacama Desert of Chile. This experiment aims to probe reionization and primordial gravitational radiation by making precise measurements of the polarization of the Cosmic Microwave Background (CMB) on the largest angular scales over 75% of the sky (+30° declination to -76°) at 40, 90, 150, and 220 GHz.

CLASS also studies our solar system and galaxy, as well as better understanding results on neutrinos and dark energy.

ACT

Atacama Cosmology Telescope

It is a six-meter diameter telescope on Cerro Toco in the Atacama Desert of northern Chile. Its goal was to make high-resolution measurements of the cosmic microwave background (CMB) temperature and polarization anisotropies and detect massive galaxy clusters via the thermal Sunyaev Zel'dovich (tSZ) effect with observations centred at 148 GHz, 218 GHz, and 277 GHz.

SPT

South Pole Telescope

The South Pole Telescope (SPT) is a 10-meter telescope operating at the National Science Foundation's South Pole research station. Designed for conducting large-area millimeter and sub-millimeter wave surveys to map primary and secondary anisotropies in the cosmic microwave background, SPT is the largest telescope ever deployed at the South Pole.

The SPT is equipped with the most powerful cosmic microwave background (CMB) camera now operating, the three-band (90, 150, 220 GHz), 16,000-detector, polarization-sensitive SPT-3G camera.

Planck

Planck was a space observatory, studying the relic photons (CMB) from the L2 point. It measured the temperature variations across the cosmic microwave background with much better sensitivity, angular resolution and frequency range than any previous satellite, giving astronomers an unprecedented view of our Universe when it was extremely young, just 300 000 years old.

DESI

The Dark Energy Spectroscopic Instrument

DESI will measure the effect of dark energy on the expansion of the universe and study its evolution over time. It will obtain optical spectra for tens of millions of galaxies and quasars, constructing a 3D map spanning the nearby universe to 11 billion light years.

The DESI Survey is being conducted on the Mayall 4-meter telescope at Kitt Peak National Observatory.  To constrain possible models of dark energy, DESI will measure the position and receding velocity of about 40 million galaxies. It will use its maps to measure two cosmological effects: baryon acoustic oscillations and redshift-space distortions.

https://www.desi.lbl.gov/science/

VRO

Rubin Observatory

The Rubin Observatory is an astronomy and astrophysics facility on Cerro Pachón in Chile. 

The 8.4-meter Simonyi Survey Telescope at Rubin Observatory, equipped with the LSST Camera — the largest digital camera ever built — will take detailed images of the southern hemisphere sky for 10 years. This will yield a treasure trove of discoveries: asteroids and comets, pulsating stars, and supernova explosions.

Rubin Observatory was specifically designed to help answer questions in four main science areas: 

1. Understanding the nature of dark matter and dark energy

2. Creating an inventory of the Solar System 

3. Mapping the Milky Way 

4. Exploring objects that change position or brightness over time

https://rubinobservatory.org/

SDSS

Sloan Digital Sky Survey

SDSS is one of the largest and most detailed astronomical surveys with optical & IR spectroscopy that has ever existed, with the goal of expanding our understanding of the large-scale evolution and structure of the universe, the formation of stars and galaxies, the history of the Milky Way, the nature of supermassive black holes, and the science behind dark energy. 

It uses a dedicated 2.5-m f/5 modified Ritchey-Chrétien altitude-azimuth telescope (picture) located at Apache Point Observatory, in southeast New Mexico; Irénée du Pont Telescope, a Ritchey-Chrétien 2.5-m f/7.5 telescope with a Gascoigne corrector lens at Las Campanas Observatory in northern Chile which made first maps of southern skies; BOSS and APOGEE spectrograms.

https://www.sdss.org/ 

DES

Dark Energy Survey

An international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

The DES is using four probes, all observed with a single instrument, to study cosmic acceleration and to measure the effects of dark energy on the expansion history of the universe and on the growth of structure. Thousands of supernova observations reveal the expansion history of the universe. Using weak gravitational lensing and galaxy clusters to learn about the formation of structure and the amount of matter in the universe. DES measures the distribution of galaxies across the cosmos through Baryon Acoustic Oscillations (BAO).

An extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, is used to carry out the project. Over a span of six years, the survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy.

https://www.darkenergysurvey.org/

CHIME

The Canadian Hydrogen Intensity Mapping Experiment

CHIME consists of four adjacent 20m x 100m cylindrical reflectors (field of view ~200 square degrees) oriented north-south. The focal axis of each cylinder is lined with 256 dual-polarisation antennas (the shortest baseline of 0.3 m), which have good sensitivity from 400 to 800 MHz.

CHIME will map the history of the expansion rate of the Universe by observing hydrogen gas in distant galaxies that were very strongly affected by Dark Energy. The experiment will measure the relic of Baryon Acoustic Oscillations (BAO), which are spherical shells of matter overdensity where galaxies and gas are more likely to be found today.

To search for FRBs, CHIME will continuously scan 1024 separate points or “beams” on the sky 24/7. Each beam is sampled at 16,000 different frequencies and at a rate of 1000 times per second

CHORD

The Canadian Hydrogen Observatory and Radio-transient Detector

CHORD will map the large-scale structure of the Universe through intensity mapping of the 21 cm emission line.  It will measure the evolution of dark energy over the redshift range z = 0 - 3.7.  At low redshift, it will be able to detect individual galaxies via the 21 cm emission line.

CHORD will be an order of magnitude more powerful than its predecessor CHIME (improving upon the mutual coupling of feeds issues in later). It will feature 512 × 6m dishes in a central array, with 64-dish outrigger arrays at two remote sites.

HERA

Hydrogen Epoch of Reionisation Array

A radio telescope dedicated to observing large-scale structure during and prior to the epoch of reionisation. The array is a large grid of 14-meter (42 ft) diameter non-tracking dishes packed into a hexagonal grid 300 m (900ft)  across with closely spaced baselines.

HERA is designed to detect radio waves in the low-frequency range of 100–200 MHz, which allows it to detect fluctuations in the emissions from neutral hydrogen gas that was found throughout the universe before stars, galaxies and black holes formed. 

MWA

The Murchison Widefield Array

MWA is a radio telescope consisting of 4,096 spider-like antennas, tuned to receive signals from the sky between 70 and 300 MHz. Each antenna is a pair of orthogonally crossed, vertical bowties (having dual-linear-polarisation), with a span of 74 cm and a height of 55 cm.

MWA antennas are arranged into ’tiles’. Each tile is a small phased array of 16 antennas in a planar, 4×4 square grid, with 1.10-meter spacing corresponding to half a wavelength at 136 MHz.

Key science projects of the MWA are understanding structure in the early universe through the detection of the Epoch of Reionization and remote imaging of magnetic and density structure in the solar corona and inner heliosphere. The performance required to meet the goal of our solar and cosmology science goals also makes MWA well-suited for blind searches for astrophysical radio transients.

uGMRT

upgraded Giant Meterwave Radio Telescope

GMRT consists of 30 fully steerable gigantic parabolic dishes of 45m diameter each spread over distances of up to 25 km. Fourteen of the thirty dishes are located more or less randomly in a compact central array in a region of about 1 sq km. The remaining sixteen dishes are spread out along the 3 arms of an approximately `Y'-shaped configuration over a much larger region, with the longest interferometric baseline of about 25 km. The array operates in six frequency bands centred around 50, 153, 233, 325, 610 and 1420 MHz. All these feeds provide dual polarisation outputs.

The primary science goals of GMRT are to detect the highly redshifted spectral line of neutral Hydrogen, expected from protoclusters or protogalaxies before they condensed to form galaxies in the early phase of the Universe, and to search for and study rapidly rotating pulsars in our galaxy.

ORT

Ooty Radio Telescope

The Ooty radio telescope is a 530-metre (1,740 ft) long and 30-metre (98 ft) wide cylindrical parabolic antenna. It operates at a frequency of 326.5 MHz with a maximum bandwidth of 15 MHz at the front end. The reflecting surface of the telescope is made of 1,100 thin stainless-steel wires running parallel to each other for the entire length of the cylinder and supported on 24 steerable parabolic frames. An array of 1,056 half-wave dipoles in front of a 90-degree corner reflector forms the primary feed of the telescope. It has an angular resolution of 2.3deg x 5.5sec(dec)'.

ORT studies space by observing radio waves from celestial objects and phenomena like the sun and pulsars. Its primary scientific applications include observing interplanetary scintillation (IPS) to probe solar activity and space weather, and searching for high-redshift neutral hydrogen.

GBD

The Gauribidanur Radio Observatory

The GEETEE (Gauribidanur Telescope) consists of 1000 dipoles arranged in a 'T' configuration, with a 1.4 km East-West arm and a 0.5 km South arm. It has been engaged in the study of radio waves at 34.5 MHz emanating from the Sun and various other diverse objects in the sky.

A radioheliograph (GRAPH) obtains two-dimensional images of the solar corona simultaneously at different frequencies in the range 40 - 150 MHz. The basic receiving element used is a log-periodic dipole (LPD), and the array consists 384 of them configured as 64 groups. The present spatial and temporal resolution of the GRAPH are ~3 arc min (@ 150 MHz) and ~256 msec, respectively.

The Gauribidanur radio interferometric polarimeter (GRIP) is an east-west one-dimensional array of 40 log periodic dipoles set up to probe the coronal magnetic field in the height range ~0.2 - 0.8 Rs, above the solar surface.

VBO

The Vainu Bappu Observatory

VBO is a prominent Indian optical observatory that hosts the 40-inch Carl Zeiss Telescope, the 1.3m J.C. Bhattacharya Telescope (JCBT) and the 90-inch Vainu Bappu Telescope (VBT).

The 90-inch VBT has two foci, an f/3.5 prime focus (with an image scale of 27 arcsec/mm) and an f/13 Cassegrain focus (with a scale of 6.7 arcsec/mm). At the prime focus, CCD cameras are used for imaging with various filters.

The JCB telescope has Ritchey-Chretien F/8 optical configuration, with a primary mirror of 1.3m diameter. The field of view of the telescope is 30 minutes of arc and the plate scale is 20 arc sec/mm. It has three instrument ports.

The 40 inch telescope has a Ritchey-Chretien F/13 optical configuration, with a primary mirror of 1.02m diameter and with a plate scale of 15.5 arcsec/mm. The telescope is attached with a stellar optical polarimeter and a medium resolution UAGS spectrograph.

Vera Rubin

The dark matter and the Galactic rotation curves 

Dr. Vera C. Rubin was an American astronomer whose work provided convincing evidence for the existence of unseen "dark" matter in the Universe. 

She worked with Kent Ford, an astronomer who had built the most sensitive spectrometer in existence at the time, back in 1965. Their groundbreaking work studying galaxy rotations used this spectrometer, which was attached to the 2.1-meter telescope at Kitt Peak National Observatory. They studied more than 60 galaxies and found that the stars at the outer edges were moving just as fast as those towards the centre.

Dark matter makes up more than 80% of all the matter in the Universe, while regular matter makes up less than 20%. Learning more about this mysterious unseen matter is one of the main science goals of the Vera-Rubin Observatory.

Jocelyn Bell Burnell

Woman behind the discovery of Pulsars

She was a British astronomer who discovered pulsars, the cosmic sources of peculiar radio pulses. While analysing miles of print-outs from the telescope, she noted a few unusual signals which she termed “scruff”. 

These “bits of scruff” seemed to indicate radio signals too fast and regular to come from quasars. Both Jocelyn and Hewish ruled out orbiting satellites, French television signals, radar, finally even “little green men.” Looking back at some papers in theoretical physics, they determined that these signals must have emerged from rapidly spinning, super-dense, collapsed stars. 

GBD

The Gauribidanur Radio Observatory

The GEETEE (Gauribidanur Telescope) consists of 1000 dipoles arranged in a 'T' configuration, with a 1.4 km East-West arm and a 0.5 km South arm. It has been engaged in the study of radio waves at 34.5 MHz emanating from the Sun and various other diverse objects in the sky.

A radioheliograph (GRAPH) obtains two-dimensional images of the solar corona simultaneously at different frequencies in the range 40 - 150 MHz. The basic receiving element used is a log-periodic dipole (LPD), and the array consists 384 of them configured as 64 groups. The present spatial and temporal resolution of the GRAPH are ~3 arc min (@ 150 MHz) and ~256 msec, respectively.

The Gauribidanur radio interferometric polarimeter (GRIP) is an east-west one-dimensional array of 40 log periodic dipoles set up to probe the coronal magnetic field in the height range ~0.2 - 0.8 Rs, above the solar surface.

VBO

The Vainu Bappu Observatory

VBO is a prominent Indian optical observatory that hosts the 40-inch Carl Zeiss Telescope, the 1.3m J.C. Bhattacharya Telescope (JCBT) and the 90-inch Vainu Bappu Telescope (VBT).

The 90-inch VBT has two foci, an f/3.5 prime focus (with an image scale of 27 arcsec/mm) and an f/13 Cassegrain focus (with a scale of 6.7 arcsec/mm). At the prime focus, CCD cameras are used for imaging with various filters.

The JCB telescope has Ritchey-Chretien F/8 optical configuration, with a primary mirror of 1.3m diameter. The field of view of the telescope is 30 minutes of arc and the plate scale is 20 arc sec/mm. It has three instrument ports.

The 40 inch telescope has a Ritchey-Chretien F/13 optical configuration, with a primary mirror of 1.02m diameter and with a plate scale of 15.5 arcsec/mm. The telescope is attached with a stellar optical polarimeter and a medium resolution UAGS spectrograph.