Successful anti-satellite missile test puts India in elite club

In an incremental advance, India successfully conducted an Anti-Satellite (ASAT) missile test, named Mission Shakti, becoming the fourth country in the world to demonstrate the capability to shoot down satellites in orbit. So far, only the United States, Russia and China have this prowess. “A short while back, our scientists have shot down a live satellite in the Low Earth Orbit (LEO) at 300 km in space,” Prime Minister Narendra Modi said, addressing the nation around noon. The satellite downed by the ASAT missile was Microsat-R, an imaging satellite which was launched into orbit on January 24, 2019 using a Polar Satellite Launch Vehicle (PSLV), a senior Defence Research and Development Organisation (DRDO) official said. India has built the broad capabilities and building blocks to develop ASAT missiles for some time as part of its Ballistic Missile Defence (BMD) programme. Mr. Modi said the aim of the test was to maintain peace, rather than war mongering. “A BMD interceptor missile successfully engaged an Indian orbiting target satellite in LEO in a ‘hit to kill’ mode’, the DRDO said in a statement. A DRDO official claimed that the ASAT missile was a modified exo-atmospheric interceptor missile of the BMD. A LEO of 300 km was chosen to “minimise” debris and it also won’t last more than a few months, the official said. Anti-satellite weapons provide the capability to shoot down enemy satellites in orbit thereby disrupting critical communications and surveillance capabilities. ASAT missiles also act as a space deterrent in dissuading adversaries from targeting the country’s satellite network. In March 2011, The Hindu had reported the then Scientific Adviser to the Defence Minister Dr. V.K. Saraswat, who later became the DRDO Chairman, as stating after an interceptor test that India had “all the technologies and building blocks which can be used for anti-satellite missions.” Meanwhile questions are being raised on the manner of announcement of the ant-satellite capability. In 2007, a similar test by China at an orbit of 800 km above earth had drawn global condemnation. This test will make it increasingly difficult for India to present itself as exhibiting more strategic restraint and responsibility than China in matters pertaining to space security, and potentially other areas of defence policy as well, said Frank O’Donnell, South Asia expert at the U.S. Naval War College, in Newport, Rhode Island. “The timing of this test, and the degree of public communications coordination among the Prime Minister’s Office, DRDO, and Ministry of External Affairs, strongly suggests that this test was ordered and conducted for domestic political reasons with the upcoming elections in mind,” he said, expressing concern on the debris generated which “cannot be controlled in terms of its destination and impact regardless of the MEA statement suggesting otherwise.”

Source: The Hindu


ISRO, French space agency seal agreement on maritime security

National space agency ISRO and its French counterpart CNES sealed an agreement to set up a joint maritime surveillance system in the country in May. The two nations will explore putting up a constellation of low-Earth orbiting satellites that will identify and track movement of ships globally – and in particular those moving in the Indian Ocean region where France has its Reunion Islands. Before that, they will initially share data from their present space systems and develop new algorithms to analyse them, according to the Paris based National Centre for Space Studies. The agreement comes a year after the broad collaboration plan the two governments initiated during French President Mr Emmanuel Macron’s visit in March last 2018. Dr K.Sivan, Chairman of the Indian Space Research Organisation, and Mr Jean-Yves Le Gall, President of CNES of France, signed the agreement in Bengaluru. “The CNES-ISRO agreement [intends] to supply an operational system for detecting, identifying and tracking ships in the Indian Ocean. [It] provides for a maritime surveillance centre to be set up in India in May this year; sharing of capacity to process existing satellite data and joint development of associated algorithms,” the CNES statement said. “For the next phase of the programme, studies for an orbital infrastructure to be operated jointly by the two countries are ongoing. CNES is working with its industry partners and with ISRO to devise the most appropriate technical solution.” The two agencies have put up two climate and ocean weather monitoring satellites Megha-Tropiques (of 2011) and SARAL-AltiKa (2013) that are considered a model. “This fleet will be augmented with the launch of Oceansat-3-Argos mission in 2020 and a future joint infrared Earth-observation satellite under ,” CNES said.

Source: https://www.thehindu.com/


ISRO and NASA can jointly work on India’s first manned mission: Former NASA administrator

The Indian Space Research Organisation and US’s NASA can work together for India’s first manned mission to space by allowing US private companies to train and select the astronauts, said a former head of the US space agency. While adding that the US can offer assistance for the Indian mission, Major General Charles Frank Bolden who was the 12th NASA Administrator suggested that India can follow what NASA does, which is not train its astronauts. He explained that NASA outsources the training of astronauts to private companies, which also provides services such as operators of space vehicles and flight contractors on a contract basis. Bolden explained that this is the ‘quickest route’ India can take. He added that until India doesn’t develop a human space flight program, as an ‘interim measure’ it can collaborate with another country’s existing program to train astronauts. These trained astronauts would then become the ‘nucleus’ of the manned space program and could contribute to training others. “India’s ISRO and NASA can work together under the umbrella of agreements that we have right now to either put Indian experiments on station or Indian astronauts on station to actually do the experiments,” said Mr Bolden, who was speaking in reference to the International Space Station program, at an interactive session at FICCI. The program is a joint project between five participating countries- NASA, Roscosmos (Russia), JAXA (Japan), ESA (Europe) and CSA (Canada). Mr Bolden who is on a tour to India said that he learnt about how ISRO is trying to understand the public-private partnership and added “do like we do in the US”. “NASA doesn’t train astronauts. We have contracts. We have been doing this for a long time…If you go to the control centre in Houston today, all flight controllers are SGT (team of contractors). The flight director is from NASA, but that NASA person is supervising a contractor team. Who was preparing the shuttle it was all the United States Alliance (conglomerate of Boeing and Lockheed Martin) people. Relying on commercial entities to operate our vehicles,” he said, adding that the contractor team would have also worked with astronauts and trained them. “Assistance can be offered by the US by allowing some US private companies in astronaut selection and training…If India asks for help, this kind of engagement can be done,” he said. Mr Bolden said that NASA can facilitate the training, by getting India in contact with such private companies. These companies have signed contracts with NASA to use NASA’s facilities to train astronauts. “Hard part is you have to pay. The thing that people used to like about being member of international space station confederation was there was no exchange of funds. You bring something else and you get opportunity to fly a crew,” he said. And pointed out that this was one of the obstacles to ISRO’s attempts at astronaut flying, because there was nothing to offer in barter. “This was because the Indian industry hadn’t decided with the government that we want to contribute. That is what he was fighting to get something to barter so that an Indian astronaut can go up,” said Bolden in reference to Mr A.S. Kiran Kumar, who was the ISRO chairman from January 2015 till January last year. Mr Kumar was also present for the FICCI session. Bolden added that he and Mr Kumar were working together to get India to engage with member nations of the International Space Station program. Bolden also pointed out that one should not be dependent on Russia to get astronauts to space. He explained that the US trains with Russia on the space program, but there are language issues. This comes in the backdrop of Russia having promised to train an Indian crew for the manned space mission. The Indian Air Force and ISRO are already working together to select astronauts by the end of this year.

Source: https://economictimes.indiatimes.com


All you need to know about India’s light combat aircraft Tejas

The term Tejas means ‘radiance’. Developed as a joint venture between Aeronautical Development Agency and Hindustan Aeronautics Limited, Tejas is a lightweight aircraft technically described as multi-role, singing-engine tactical fighter. Specially manufactured for induction into the Indian Navy and Indian Air force, Tejas comes with two variations. Tejas is an indigenously manufactured Light Combat Aircraft (LCA). Notably this is among the world’s smallest and lightest multi-role fighter aircraft belonging to the Supersonic class. The highlights of this tailless Aircraft include single-engine and a compound delta wing. In the mission of its development, we see ADA and HAL partner also making use of the expertise of DRDO, CSIR, BEL, DGAQA, IAF and IN. Upon its deployment, Tejas will meet the diverse requirements of the Indian Air Force (IAF) and Indian Navy (IN). Specifications and performance Tejas is known for its high degree of agility and maneuverability. These characteristics are achieved by virtue of its tailless compound wing delta configuration that is said to be aerodynamically unstable. Tejas is designed to satisfy the demands of the modernized air force. This multi-role aircraft is capable of challenging air defense roles and all-round air superiority. In the aerodynamic designing of this aircraft, a deep study and experimentation with the principles of computational fluid dynamics and wind tunnel studies have gone into. The most amazing aero-dynamic features of Tejas makes it stand for an excellent performance across a broader fighter envelope. The highly optimized wing of the aircraft shows up the right variation of thickness, twist and camber though its span. The designers have ably adjusted the cross-sectional area distribution for achieving remarkable high speed characteristics. The leading edge slats are particularly suitable for promising aerodynamic performance. In order to prevent buzz and to bring down distortion throughout the flight envelope, the makers have incorporated wing shielded and bifurcated air intake duct fitted with diverts. These aspects harmoniously match with the engine design. Dimensions Length: 13.20 meters; Height: 4.40 meters; and Wing Span: 8.20 meters Weights Empty: 9800 Kilograms; Take Off clean: 6500 kilograms; and External Stores: 3500 kilograms Aircraft Performance Altitude: 50,000 feet; Max Speed at all altitudes: Supersonic; and ‘g’ limits: +8/- 3.5 Power plant F404-GE-IN20 Size: Diameter 890 mm, Length 3.9 m Weight: Max Weight 1,035 kg (2,282 lb) Engines capability: Thrust 9,163 kg (20,200 lb) Weapons The efficiency and worth of any modern fighter aircraft depends on the weapons it is capable of delivering on the target. Tejas can carry a veritable plethora of air to surface, air to air, standoff and precision guided weaponry. In the air-to-air arena, Tejas can carry long range and beyond visual range weapons. It can also tackle any kind of close combat threat by handling highly agile and high off-boresight missiles. A broad range of air to ground munitions and a highly accurate navigation and attack system makes it possible for the aircraft to prosecute the surface targets both over the land or at the sea with the mission accomplished with high degree of accuracy. These features bestow the multi-swing role capabilities to this highly touted fighter jet aircraft Tejas.

Source: https://www.businessinsider.in/


ISRO awards 96 people, teams for their contributions to space projects, programs

The Indian Space Research Organisation presented 96 individuals with awards at a ceremony held at its Antariksh Bhavan headquarters in Bengaluru. The awards were in recognition of various contributions made by individuals and organisations towards the success of ISRO’s projects and programmes. The ‘ISRO Awards‘ were distributed by former Chairman Dr K Kasturirangan and present Chairman Dr K Sivan. This was the 12th edition of the Awards, the first of which were given away in 2007. “ISRO Awards have over the years become prestigious ones among the space fraternity. (The Awards) have been executed very well over the years,” Dr Kasturirangan said, This year, four categories of contributions were recognised by ISRO: 50 Young Scientist Awards, 20 Merit Awards, 10 Performance Excellence Awards and 16 Team Excellence Awards. Recipients were chosen for their outstanding contributions to ISRO’s efforts in the year 2017. The selection panel consisted of officials from various centres of ISRO across the country. In addition to the four main categories awarded this year, Outstanding Contribution and Life Time Achievement Awards are also given away biennially. Dr Sivan addressed ISRO employees at the ceremony, persuading them to take on challenges to come with single-minded devotion. “Congratulations to all the award winners,” Dr Sivan said,  I appreciate the self-driven nature of employees which is taking ISRO to greater heights,” Dr Sivan said. Directors from various centres of ISRO, employees from ISRO’s headquarters and the Department of Space were present for the awards.

Source: https://www.firstpost.com


India’s First Three-Orbit Mission With Solar-Powered Fourth Stage: ISRO To Launch PSLV-C45 On 1 April

In its first three-orbit mission that launches satellites into three different orbits, ISRO is set to launch PSLV-C45 on 1 April 2019, reports. ISRO will place advanced electronic intelligence satellite EMISAT along with 28 commercial satellites in the orbit. At first the launch was scheduled on 4 March but was delayed. Explaining the cause behind the delay, ISRO chairman Dr K Sivan said that internal system readiness and other technical factors were addressed as PSLV-C45 is the first three-orbit mission of ISRO and first to use solar panel in rocket fourth stage (PS4). Confirming the launch scheduled on 1 April, Vikram Sarabhai Space Centre (VSSC) director Mr S Somanath said that so far ISRO had only conducted two-orbit missions. “After launch of electronic intelligence satellite EMISAT into orbit at 780 km, it will inject 28 guest satellites into orbit at 504 km. Then rocket fourth stage (PS4) instead of burning out, will automatically reorient itself to establish an orbital platform at 485 km orbit to carry out scientific experiments,” he said. Following this mission, PSLV-C46 will launch Cartosat-3 and PSLV-C47 will launch RISAT-2BR 1. While former is a remote sensing satellite, latter is a radar imaging satellite for reconnaissance and strategic surveillance.

Source: https://swarajyamag.com/


Boeing 737 Max crash raises tough questions on aircraft automation

Mr Tom Enders just couldn’t resist the swipe at the competition. It was June 2011, and the chief executive officer of Airbus SE was on a stage at the Paris air show after the planemaker won in a matter of days an unprecedented 600 orders for its upgraded A320neo airliner, while Boeing Co. stood on the sidelines. “If our colleagues in Seattle still maintain we’re only catching up with their 737, I must ask myself what these guys are smoking,” Mr Enders blurted out, to the general amusement of the audience, while Boeing representatives at the back of the room looked on. Boeing had wavered on its decision whether to follow Airbus’s lead and re-engine the 737 or go with an all-new aircraft. Customers were willing to wait for “something more revolutionary,” as Mr Jim Albaugh, at the time Boeing’s head of commercial aircraft, said then. But the European manufacturer’s blow-out success with the A320neo, essentially a re-engineered version of its popular narrow-body family, would soon force Boeing’s hand. As the A320neo became the fastest-selling plane in civil aviation history as Airbus picked off loyal Boeing customers like American Airlines Group, the US company ditched the pursuit of an all-new jet and responded in July 2011 with its own redesign, the 737 Max. “The program was launched in a panic,” said Mr Sash Tusa, an analyst at Agency Partners, an equity research firm in London. “What frightened Boeing most of all was losing their biggest and most important customer. American Airlines was the catalyst.” It turned out that Chicago-based Boeing wasn’t too late to the party in the end: While the Max didn’t quite replicate the neo’s order book, it did become the company’s fastest seller as airlines scrambled to cut their fuel bills with new engines that promised savings of 20 per cent or more. All told, the Max raked in about 5,000 orders, keeping the playing field fairly level in the global duopoly between Airbus and Boeing.

Close scrutiny

Now the 737 Max is grounded globally, after two almost factory-fresh jets crashed in rapid succession. As a result, the repercussions of Boeing’s response to Airbus’s incursion are under the microscope. Getting particular scrutiny are the use of more powerful, fuel-saving engines and automated tools to help pilots control the aircraft. After the grounding, Boeing said that it “continues to have full confidence in the safety of the 737 Max, and that it was supporting the decision to idle the jets “out of an abundance of caution.” The company declined to comment beyond its public statements. In late October, a plane operated by Lion Air went down minutes after taking off in Jakarta, killing all 189 people on board. Then on March 10, 2019 another 737 Max crashed, this time in Ethiopia en route to Kenya. Again, none of the 157 people on board survived the impact. There are other similarities that alarmed airlines and regulators and stirred public opinion, leading to the grounding of the 737 Max fleet of more than 350 planes. According to the Federal Aviation Administration, “the track of the Ethiopian Airlines flight was very close and behaved very similar to the Lion Air flight.” After decades of steadily declining aircraft accidents, the question of how two identical new planes could simply fall out of the sky minutes after takeoff has led to intense scrutiny of the 737 Max’s systems. Adding to the chorus in the wake of the crash was President Donald Trump, who lamented the complexities of modern aviation, suggesting that people in the cockpit needed to be more like nuclear physicists than pilots to command a jet packed with automated systems. “Airplanes are becoming far too complex to fly. Pilots are no longer needed, but rather computer scientists from MIT,” the president said in the first of a pair of tweets on March 12, darkly warning that “complexity creates danger.”

Analog machine

Automation plays a limited role in the 737 Max. That’s because the aircraft still has essential analog design and layout features dating back to the 1960s, when it was conceived. It’s a far older concept than the A320, which came to market at the end of the 1980s and boasted innovations like fly-by-wire controls, which manipulate surfaces such as flaps and horizontal tail stabilizers with electrical impulses and transducers rather than heavier hydraulic links. Upgrading the 737 to create the Max came with its own set of issues. For example, the 737 sits considerably lower to the ground, so fitting the bigger new engines under the wings was a structural challenge (even with the squished underbelly of the engine casing). In response, Boeing raised the front landing gear by a few inches, but this and the size of the engines can change the plane’s center of gravity and its lift in certain manoeuvres. Boeing’s technical wizardry for the 138- to 230-seat Max was a piece of software known as the Manoeuvring Characteristics Augmentation System, or MCAS. It intervenes automatically when a single sensor indicates the aircraft may be approaching a stall. Some pilots complained, though, that training on the new system wasn’t sufficient and properly documented. “The benefits of automation are great, but it requires a different level of discipline and training,’’ said Mr Thomas Anthony, director of the Aviation Safety and Security Program at the University of Southern California. Pilots must make a conscious effort to monitor the plane’s behavior. And reliance on automation means they will take back control only in the worst situations, he said.

Errant sensor

With the Lion Air crash, data from the recovered flight recorders points to a battle in the cockpit between the software and the pilots who struggled in vain to keep control. The data showed that an errant sensor signaled the plane was in danger of stalling and prompted the MCAS to compensate by repeatedly initiating a dive. The pilots counteracted by flipping a switch several times to raise the nose manually, which temporarily disabled MCAS. The cycle repeated itself more than two dozen times before the plane entered its final deadly dive, according to the flight data. With the flight and cockpit voice recorders of the Ethiopian plane now in France for analysis, the interaction between the MCAS system and the pilots will again be under close scrutiny, probably rekindling the broader debate about who or what is in control of the cockpit. That man-versus-machine conundrum has been central to civil aviation for years. Automation has without doubt made commercial flying much safer, as planemakers added systems to help pilots set engine thrust, navigate with greater precision and even override human error in the cockpit. For example, automation on modern aircraft keeps pilots within a so-called flight envelope to avoid erratic manoeuvres that might destabilize the aircraft. Analyses of flight data show that planes have more stable landings in stormy, low-visibility conditions when automation is in charge than on clear days when they land by sight.

Sully’s miracle landing

The most daring descent in recent memory, Chesley “Sully” Sullenberger’s landing of US Airways Flight 1549 in the Hudson River in early 2009, is Exhibit A of how an interconnected cockpit worked hand-in-hand with an experienced pilot. Automatic pitch trim and rudder coordination assisted manual inputs and kept the Airbus A320 steady on its smooth glide into the icy water. The drama showed that automation can play a crucial support function, provided a pilot is fully trained and the aircraft properly maintained. “Some people are saying modern aircraft such as the 737 Max are too complex,” said Mr Dave Wallsworth, a British Airways captain on the Airbus A380 double-decker. “I disagree. The A380 is a far more complex aircraft and we fly it very safely every day. Pilots are capable of understanding aircraft systems so long as the manuals contain the information we need.” Airbus traditionally has pushed the envelope on automation and a more modern cockpit layout, with larger screens and steering by joystick rather than a central yoke, turning pilots into something akin to systems operators. Boeing’s philosophy, on the other hand, has been to leave more authority in the hands of pilots, though newer designs also include some computerized limits. Like Airbus planes, the latest aircraft from Seattle —where Boeing makes most of its jetliners — are equipped with sophisticated autopilots, fly-by-wire controls or systems to set speed during landings. “The big automation steps came in the 1980s with the entry into service of the A320 and the whole fly-by-wire ethos,” said Mr John Strickland, an independent aviation analyst. “I don’t think automation per se is a problem, we see it in wide-scale use in the industry, and as long as it is designed to work hand-in-hand with pilots and pilots understand how to use it, it shouldn’t be an issue.”

Erratic movements

But the counter-argument is that increasingly complex systems have led computers to take over, and that many pilots may have forgotten how to manually command a jet — particularly in a moment of crisis. That criticism was leveled at Airbus, for example, after the mid-Atlantic crash of Air France Flight 447 in 2009 that killed all 228 people on board. Analysis of the flight recorders showed the crew was confused by stall warnings and unreliable speed readings, leading to erratic manoeuvres that ended in catastrophe. “I grew up on steam gauges and analog, and the modern generation on digital and automation,” said Mr Jon Weaks, president of the Southwest Airlines Pilots Association and a Boeing 737 captain for the Dallas-based airline. “No matter what you grew up on, you have to fly the plane. If the automation is doing something you don’t want it to do or that you don’t understand, you have to disconnect it and fly the plane.” A 2013 report by the FAA found more than 60 percent of 26 accidents over a decade involved pilots making errors after automated systems abruptly shut down or behaved in unexpected ways. And the 2016 inspector general’s report at the FAA noted that as the use of automation increases, “pilots have fewer opportunities to use manual flying skills.” “As a result, the opportunities air carrier pilots have during live operations to maintain proficiency in manual flight are limited and are likely to diminish,” the report found.

Source: https://www.business-standard.com/


NASA Wants to Put a Rover on the Moon by 2023

THE WOODLANDS, Texas — NASA’s timeline for lunar exploration has tended to jump from sending small commercial landers as soon as possible to getting human missions there by 2028, but on (March 18), agency officials offered a target date for a key intermediate step: They want to put a rover on the moon by 2023. Those comments came during a NASA town hall at the Lunar and Planetary Science Conference being held here this week. During the event, leaders emphasized the current focus on the moon, both from the science perspective and from the human-exploration perspective. They also walked through the timeline expected for some of these milestones. NASA had already announced that it was hoping to place science instruments on the surface with commercially built landers as soon as this year, and that its end target was to land humans by 2028. But intermediate steps hadn’t been discussed in much detail. During presentation, that changed. “We’re trying to get to the moon with a rover as soon as possible, we’re really trying to target 2023,” Mr Steve Clarke, the deputy associate administrator for exploration within the Science Mission Directorate, said during the event. Clarke added that such a rover could be important for studying volatile compounds on the moon, a class of chemicals that includes water. He also suggested such a rover could clock in between 660 and 1,100 lbs. (300 and 500 kilograms). He also discussed advanced capabilities rovers could take on. “Certainly, we’ll be going to one of the poles,” Mr Clarke said. “And long-duration operation, we’d like to be able to go and operate for a period of months, not just weeks.” Mr Clarke did not specify whether developing these capabilities would be feasible by the 2023 schedule goal, or whether they would be included only in a second generation of lunar rovers. Throughout the event, NASA personnel seemed to emphasize the agency’s desire to make sure scientists feel included in the quest to return humans to the moon, which can sometimes feel like a separate endeavor directed toward separate goals. That science focus included the major piece of infrastructure within NASA’s moon plans, a space station nicknamed Gateway, which would serve as a base camp for both science projects and astronaut missions. “For us to understand how to develop the Gateway, we need to understand how you’d like to utilize it,” Mr Jake Bleacher, acting chief exploration scientist in the Human Exploration and Operations Mission Directorate, said during yesterday’s event. Of course, NASA isn’t just waiting around for scientists’ wish lists; the agency has its own as well. “Ultimately, I think we would all like to get more pieces of the moon back to Earth,” Bleacher said. “I think Gateway might play a role in that.”

Source: https://www.space.com/


Young Scientist Programme Launched

Indian Space Research Organisation has launched a special programme for School Children called “Young Scientist Programme” “YUva VIgyani KAryakram” (युविका) from this year, in tune with the Government’s vision “Jai Vigyan, Jai Anusandhan”. The Program is primarily aimed at imparting basic knowledge on Space Technology, Space Science and Space Applications to the younger ones with the intent of arousing their interest in the emerging areas of Space activities. The program is thus aimed at creating awareness amongst the youngsters who are the future building blocks of our Nation. This will further help them to appreciate what they are being taught in the school and its real application in Space Science & Technology. ISRO has chalked out this programme to “Catch them young”. The programme will be of around two weeks duration during summer holidays and the schedule will include invited talks, experience sharing by the eminent scientists, facility and lab visits, exclusive sessions for discussions with experts, practical and feedback sessions. It is proposed to select 3 students each from each State/ Union Territory to participate in this programme every year covering CBSE, ICSE and State syllabus. Those who have finished 8th standard and currently studying in 9th standard will be eligible for the programme. ISRO has approached the Chief Secretaries of the respective States/ Administrators of Union Territories in India to arrange for the selection of three students from each of their State/UT and communicate the list to ISRO. The selection is based on the academic performance and extracurricular activities, which is clearly mentioned in the selection criteria already circulated to Chief Secretaries of States/ Administrators of UTs. Students belong to the rural area have been given special weightage in the selection criteria. The selected students will be accommodated in ISRO guest houses/hostels. Expenditure towards the travel of student (II AC fare by train from nearest Railway Station to the reporting centre and back), course material, lodging and boarding etc., during the entire course will be borne by ISRO. II AC fare will also be provided to one guardian/parent for drop and pick up of student from the reporting centre.

Source: https://www.isro.gov.in/


Astrosat Picture of the Month of Feb, 2019

New population of Ultraviolet stars in the Globular Cluster NGC 2808

The Sun is a constant presence in our lives and is about 5 billion years old. But will the Sun itself change in the millions of years to come? Any such change will occur so far into the future, that astronomers need to look to alternate places in the sky to understand this. Globular clusters are the best laboratories to study the fate of stars. This month, APOM brings forth a globular cluster called NGC 2808 located at a distance of about 47,000 light years in the constellation Carina. This is the third globular cluster in APOM, after NGC 1851 and NGC 288. NGC 2808 is one of the most massive globular clusters that we know, with a stellar membership of more than a million stars. Being nearly 11 billion years old, stars like the Sun and heavier stars have evolved to later stages of evolution. Due to the large number of stars present in globular clusters, stars with different masses, and in different evolutionary stages can be studied together. This is because it is believed that all stars in the cluster formed from the same material at approximately the same time. NGC 2808 is unique because very recent optical studies have shown that it houses many distinct populations of stars (five in this case) within it, the maximum found in any globular cluster till date. Stars at the same evolutionary stage but having similar masses in this cluster seem to have other properties (eg. brightness, material from which it is made) that are slightly different. These are then said to belong to different populations. The stars that are bright in ultraviolet in this globular cluster have been studied using UVIT on-board AstroSat by a group of researchers from the Indian Institute of Space science and Technology (IIST), Trivandrum and Tata Institute of Fundamental Research, Mumbai. Using ultraviolet light from different wavebands (filters), these authors have identified stars belonging to later stages of stellar evolution, eg. Horizontal Branch stars, hot stars that have passed through the Asymptotic Giant Branch phase. They have also established the presence of four different populations of stars that are seen in the UV, including a new population for the first time. These UV populations of stars are related to the five groups of optical stars mentioned above. Earlier studies had shown the presence of a certain group of UV stars called the Red Horizontal Branch stars in the cluster. The current study has utilized the capabilities of UVIT to report that it is not one group, but rather a mixture of two different populations. This study of the UV populations in the cluster would help in refining our understanding of the formation of multiple populations in globular clusters. The paper describing the results is accepted for publication by the Monthly Notices of Royal Astronomical Society and can be found here. Accompanying science story is here.

 Source: https://www.isro.gov.in/