Dismiss Notice
Welcome to IDF- Indian Defence Forum , register for free to join this friendly community of defence enthusiastic from around the world. Make your opinion heard and appreciated.

India's Deep Space Exploration Observatories (Orbital)

Discussion in 'Education & Research' started by Indx TechStyle, Dec 11, 2016.

  1. Indx TechStyle

    Indx TechStyle Lieutenant FULL MEMBER

    Joined:
    Sep 22, 2016
    Messages:
    663
    Likes Received:
    1,252
    Country Flag:
    India
  2. Indx TechStyle

    Indx TechStyle Lieutenant FULL MEMBER

    Joined:
    Sep 22, 2016
    Messages:
    663
    Likes Received:
    1,252
    Country Flag:
    India
    Announcement of Opportunity (AO) soliciting proposals for second AO cycle observations
    Announcement of Opportunity (AO) soliciting proposals for second AO cycle observations
     
    Aqwoyk likes this.
  3. Indx TechStyle

    Indx TechStyle Lieutenant FULL MEMBER

    Joined:
    Sep 22, 2016
    Messages:
    663
    Likes Received:
    1,252
    Country Flag:
    India
    Astronomers discover ‘powerful cosmic double whammy’ with help of India’s GMRT
    A supermassive black hole and the collision of giant galaxy clusters have combined to create a cosmic acceleration.
    By: PTI | Washington |
    Updated: January 7, 2017 5:06 PM
    [​IMG]The two clusters are both very massive, each weighing about a quadrillion – or a million billion – times the mass of the Sun.
     
  4. Indx TechStyle

    Indx TechStyle Lieutenant FULL MEMBER

    Joined:
    Sep 22, 2016
    Messages:
    663
    Likes Received:
    1,252
    Country Flag:
    India
    Discovery of a hot companion associated with a Blue Straggler in NGC-188 using AstroSat UVIT data
    For details:
    [​IMG]FUV (left) and NUV (right) images of NGC-188 obtained on 18 February 2016.
    WOCS-5885 is marked as red square


    [​IMG]Spectral Energy Distribution (SED) for WOCS-5885. Points in light green are from UVIT

    Story of the Week - Archive
    Jan 09, 2017 : Discovery of a hot companion associated with a Blue Straggler in NGC-188 using AstroSat UVIT data
    Jan 02, 2017 : Golden Jubilee of Composite Materials Activities at ISRO
    Dec 26, 2016 : Indigenous Development of 4.5 ton Vertical Planetary Mixer
    Dec 19, 2016 : First National Finite Element Developers/FEASTSMT Users’ Meet at VSSC
    Dec 05, 2016 : National Rollout of GeoMGNREGA held at Vigyan Bhavan, New Delhi
    Nov 28, 2016 : Applications of Unmanned Aerial Vehicle (UAV) based Remote Sensing in NE Region
    Nov 21, 2016 : ISRO Telemetry, Tracking and Command Network (ISTRAC) Celebrates Ruby Year
     
    Gessler likes this.
  5. Indx TechStyle

    Indx TechStyle Lieutenant FULL MEMBER

    Joined:
    Sep 22, 2016
    Messages:
    663
    Likes Received:
    1,252
    Country Flag:
    India
  6. Tejasmk3

    Tejasmk3 2nd Lieutant FULL MEMBER

    Joined:
    Oct 22, 2016
    Messages:
    314
    Likes Received:
    611
    Country Flag:
    India



    ‘Vampire’ star caught in the act by Indian space observatory ASTROSAT

    India's first dedicated space observatory, ASTROSAT, has captured the rare phenomenon of a small, 6-billion-year-old "vampire" star "preying" on a bigger celestial body.
    By: PTI | New Delhi | Published: January 29, 2017 1:00 PM

    [​IMG]
    “The small star becomes bigger, hotter and bluer, which gives it the appearance of being young, while the ageing companion burns out and collapses to a stellar remnant,” said Annapurni Subramaniam, a Professor at the Indian Institute of Astrophysics. (Representative image: Reuters)

    India’s first dedicated space observatory, ASTROSAT, has captured the rare phenomenon of a small, 6-billion-year-old “vampire” star “preying” on a bigger celestial body. Scientists say the smaller star, also called a “blue straggler”, feeds off its companion star by sucking out its mass and energy, causing its eventual death.

    “The most popular explanation is that these are binary systems in which the smaller star sucks material out of the bigger companion star to become a blue straggler, and hence is called a vampire star.

    “The small star becomes bigger, hotter and bluer, which gives it the appearance of being young, while the ageing companion burns out and collapses to a stellar remnant,” said Annapurni Subramaniam, a Professor at the Indian Institute of Astrophysics.

    Though this phenomenon is not unheard of, the observation of the entire process through the telescope will provide insights that will help scientists in studying the formation of ‘blue straggler’ stars.

    This discovery also highlights the capabilities of the telescopes on ASTROSAT, a dedicated space observatory satellite launched in September 2015.

    The study was recently published in Astrophysical Journal Letters by a team of scientists from IIA, Inter-University Centre of Astronomy and Astrophysics (IUCAA), Tata Institute of Fundamental Research (TIFR), Indian Space Research Organisation (ISRO) and the Canadian Space Agency (CSA).

    Scientists are now looking to understand the chemical composition of the ‘blue straggler’ using high resolution spectroscopy, which could reveal more about the evolution of these peculiar celestial objects.

    The stars are part of a “cluster” called NGC 188 formed some 6 billion years ago, and are much older than the sun, which is believed to have come into existence nearly 4.5 billion years ago.

    “As the sucked up material from the ageing star will be polluted with material processed within the ageing star, this blue straggler will throw light on the kind of nuclear processing that happens in ageing stars”, Subramaniam, also the Calibration Scientist of UVIT on board the ASTROSAT, said.
     
  7. Indx TechStyle

    Indx TechStyle Lieutenant FULL MEMBER

    Joined:
    Sep 22, 2016
    Messages:
    663
    Likes Received:
    1,252
    Country Flag:
    India
    X-ray Polarimeter Satellite (XPoSat) Mission

    Source: Annual Report 2016-17
     
  8. Indx TechStyle

    Indx TechStyle Lieutenant FULL MEMBER

    Joined:
    Sep 22, 2016
    Messages:
    663
    Likes Received:
    1,252
    Country Flag:
    India
    India's AstroSat catches astronomical imposter
    India’s AstroSat catches astronomical imposter Download PDF

    Indian scientists leading an international team of astronomers showed that a new object discovered in the sky, believed to be related to the latest gravitational wave discovery, was in fact an unrelated gamma ray burst.

    The LIGO scientific collaboration’s discovery of GW170104 led to a frenzy of activity among partner astronomers around the world, each trying to find any associated explosions in the sky. The Hawaii-based ATLAS group found a source that was in the right place in the sky, and was fading fast – causing excitement all around. But was it really associated with GW170104? Was it the first discovery of an optical source related to a gravitational wave detection? No, according to a study by the AstroSat CZTI team and the international GROWTH collaboration.

    While studying observations of the source – named ATLAS17aeu – the team noticed something odd about how fast it was fading. “Analysing the data, I concluded that ATLAS17aeu must be related to some explosion on 5th January, not the 4th”, says Varun Bhalerao (IIT Bombay), the lead author in this study. The team had already used CZTI to look for X-rays coming from GW170104, and not seen any. CZTI (Cadmium Zinc Telluride Imager), a gamma ray telescope on ISRO’s maiden space observatory AstroSat, proved to be the most sensitive instrument in the world to find transient sources with sub-second durations. So if there was another burst in the sky, they were sure they would find it in CZTI data. Varun continues, “I shot off an email to my student Sujay, asking him to search for a burst in CZTI data in the calculated time window. And then I noticed an email from Vidushi (another student) in my inbox: she had found the burst I was looking for!”

    The culprit seemed to be a gamma ray burst GRB 170105A – that exploded in the same part of the sky 21 hours later. But to be sure of this, astronomers needed more data. Enter GROWTH: Global Relay of Observatories Watching Transients Happen. This multi-national team had already swung into action, observing ATLAS17aeu with optical, X-ray and radio telescopes. Team member Dipankar Bhattacharya (IUCAA) said, “The team studied the source with radio, optical and X-ray telescopes for a few days, till it faded away into oblivion. Based on its behaviour we concluded that this event signalled the birth of a new black hole when a massive star imploded in a galaxy several billion light years away.”

    This gamma ray burst was missed by several other international satellites which were pointing at other parts of the sky at that instant. It was detected only by the Cadmium Zinc Telluride Imager (CZTI) on AstroSat, and by the Chinese-European POLAR instrument. “This is the result of insightful instrument design, imaginative onboard software, and collaborative data analysis from a nationwide team”, says A.R. Rao (TIFR). But the team has its eyes on the prize: finding the first electromagnetic counterpart to a gravitational wave source. And the highly sensitive CZTI might not be enough. Rao adds, “We need wide angle detectors scattered over interplanetary space to discover X-rays from LIGO sources. The CZTI team has proposed a small sized instrument called MOTIVE to ISRO as a likely payload for a future interplanetary mission. Together, CZTI and MOTIVE can revolutionize the field!”

    -----------------------------------------------------------------------------------------------------------

    CZT-Imager is built by a consortium of Institutes across India. The Tata Institute of Fundamental Research, Mumbai, led the effort with instrument design and development. Vikram Sarabhai Space Centre, Thiruvananthapuram provided the electronic design, assembly and testing. ISRO Satellite Centre (ISAC), Bengaluru provided the mechanical design, quality consultation and project management. The Inter University Centre for Astronomy and Astrophysics (IUCAA), Pune did the Coded Mask design, instrument calibration, and Payload Operation Centre. Space Application Centre (SAC) at Ahmedabad provided the analysis software. Physical Research Laboratory (PRL) Ahmedabad, provided the polarisation detection algorithm and ground calibration. A vast number of industries participated in the fabrication and the University sector pitched in by participating in the test and evaluation of the payload. The Indian Space Research Organisation funded, managed and facilitated the project.

    This work was supported by the GROWTH project funded by the National Science Foundation under Grant No 1545949. GROWTH is a collaborative project between California Institute of Technology (USA), Pomona College (USA), San Diego State University (USA), Los Alamos National Laboratory (USA), University of Maryland College Park (USA), University of Wisconsin Milwaukee (USA), Tokyo Institute of Technology (Japan), National Central University (Taiwan), Indian Institute of Astrophysics (India), Inter-University Center for Astronomy and Astrophysics (India), Weizmann Institute of Science (Israel), The Oskar Klein Centre at Stockholm University (Sweden), Humboldt University (Germany). GROWTH is supported by the Science and Engineering Research Board, Department of Science and Technology, India.

    More information about the discovery of the gravitational wave source GW170104 can be obtained at https://www.ligo.caltech.edu/page/press-release-gw170104, and in the IndIGO press release.
     
  9. Zer0reZ

    Zer0reZ 2nd Lieutant FULL MEMBER

    Joined:
    Jun 10, 2017
    Messages:
    234
    Likes Received:
    288
    Country Flag:
    India
    Indian astronomers get an insight into Crab nebula pulsar

    A star spectacularly exploded about 7500 years ago. Situated at about 6500 light years away, the dazzling light from the explosion reached the earth during 1054 CE. The luminosity of the explosion was brighter than million suns, and was hence even visible in day light to the wonderment Chinese astronomers. They were amazed at the appearance of a new bright star in the sky and noted it in their record. This is the earliest record of the crab nebula supernova explosion.

    Many years later, with the advent of telescope, astronomers found a nebula, a cloud like structure. It became clear that it is the remnant of an exploded star. It was in the 1960s, astronomers could detect the rapidly rotating neutron star- a pulsar- inside a gas envelop. The massive core of the exploded star had collapsed into the neutron star, one of the most dense objects in the universe.

    Now Indian astronomers, wielding powerful Cadmium–Zinc–Telluride Imager (CZTI) on-board the Indian astronomy satellite, AstroSat, have obtained the ‘most precise hard X-ray polarization measurements of the Crab pulsar so far’. The discovery has been announced on Monday in journal Nature Astronomy. Since the launch of AstroSat in September 2015, the Crab nebula has been extensively observed on 21 different occasions during its first 18 months of operation.

    Some of the neutron stars are highly magnetised and rotate at rapid pace. They emit a beam of light and other electromagnetic waves, just like a lighthouse, in a particular plane. Due to pulsed appearance of emission, these neutron stars are called as pulsars. When the beam is pointed towards the earth, astronomers can detect it.

    [​IMG]


    " When we compare data collected in optical wavelengths, we find variation in off-pulse emission in hard X-ray. This means these hard x-rays originated in the pulsar itself and not from the surrounding materials " : Prof Vadawale
    “Crab nebula hosts a Crab pulsar, which is a typical example of a young, rapidly spinning, strongly magnetized neutron star that generates broadband electromagnetic radiation by accelerating charged particles to near light speeds in its magnetosphere,” Prof Santosh V. Vadawale of Physical Research Laboratory, Ahmedabad, lead author of the study, told India Science Wire.

    With just a size of 28–30 km in diameter, the Crab pulsar contains 1.4 solar masses and rotates thirty times every second emitting a pulse of radiation in almost all wavelengths every 33 milliseconds.

    Because they are so tiny it is not practical to look at pulsars through telescope to study its shape and dynamics. The spectra of the pulsar can be used to calculate physical dimension including the mass density of neutron star, while time variability in the pulses give the absolute physical dimension. Just as you cannot solve two variables with just one equation, if one had to pinpoint the dynamics of neutron stars we need additional information.

    Degree and direction of x-ray polarisation help in understanding neutron stars better. The polarisation of x-rays can occur when charged particles move in strong magnetic fields of pulsar. The x-rays scattered from surrounding materials also give raise to polarisation. “Investigating the polarisation of emitted x-rays is a good diagnostic to study the location and fundamental mechanisms behind emission processes,” explained Prof A. R. Rao of TIFR.

    [​IMG]
    The reception of emission when the beam is turned towards the earth is natural. However, this research has found “polarization is varying the most in the ‘off-pulse’ mode, when the beam is turned away from the earth, duration when no contribution from the pulsar is expected, which poses a serious challenge to most of the current theories of how this object produces X-rays” says Prof Dipankar Bhattacharya of Inter-University Centre for Astronomy and Astrophysics (IUCAA).

    Hard X-ray emissions observed by CZTI come from all over the nebula, whereas the optical band includes only those from pulsar. “When we compare data collected in optical wavelengths, we find variation in off-pulse emission in hard X-ray. This means these hard x-rays originated in the pulsar itself and not from the surrounding materials,” said Prof Vadawale. Further they also detected difference in polarisation in optical and x-ray band just trailing a pulse peak. What this implies is yet to be ascertained.

    Using available data, astrophysicists developed many models to explain pulsars. The results from this study rules out two of the most popular models and raises questions on the rest, forcing the astrophysicists to go back to their drawing boards. Incipient attempts to study x-ray polarisation from pulsars commenced in early 1970s, the work came to standstill in 1978 due to lack of sensitise instrumentation. AstroSAT has restarted this exploration and soon ISRO is going to launch a dedicated satellite mission XpoSat with X-ray Polarimeter (POLIX) aboard to study X-ray polarisation measurement of hard X-ray sources.

    The research team included S. V. Vadawale, T. Chattopadhyay, N. P. S. Mithun (all from Physical Research Laboratory, Ahmedabad); A. R. Rao (TIFR, Mumbai); D. Bhattacharya, A. Vibhute, G. C. Dewangan, R. Misra (all from IUCAA, Pune); V. B. Bhalerao (IIT Mumbai); B. Paul (RRI, Bengaluru); A Basu, B. C. Joshi (NCRA Pune) and S. Sreekumar, E. Samuel, P. Priya, P. Vinod (all from VSSC, Thiruvananthapuram) and S. Seetha (ISRO, Bengaluru). (India Science Wire)
     
    Last edited: Nov 10, 2017
    Wolfpack likes this.
  10. Wolfpack

    Wolfpack Captain FULL MEMBER

    Joined:
    Oct 29, 2016
    Messages:
    1,016
    Likes Received:
    1,260
    Country Flag:
    India
    Just wondering how much would it cost to send up a Astrosat kind of telescope up into space, using our ISRO, if Indian citizens send their own private Space telescopes into space.
     

Share This Page