Why is the finding about Centaurus X-3 considered unusual?
- A.A high-mass X-ray binary usually captures stellar wind directly instead of forming a disk
- B.The pulsar was found to have no magnetic field at all
- C.The companion star was found to be smaller than the Sun
- D.The system was found to lie outside our galaxy
Correct answer
Explanation
The correct answer is that a high-mass X-ray binary usually captures stellar wind directly instead of forming a disk. In such pairs the companion is a massive star that sheds a strong wind, and the pulsar ordinarily feeds on that wind as it passes, so an orderly disk of matter is not expected. Finding signs of a disk in Centaurus X-3 therefore means the emission models built for the system will have to be changed to allow for light coming from the disk itself. Option B is wrong because a pulsar is by definition a neutron star with an extremely strong magnetic field, and the field is what channels matter to the poles. Option C contradicts the system described, in which the companion carries more than 10 times the mass of the Sun. Option D is incorrect as well, since the object lies about 24000 light years away, within our own galaxy, in the constellation Centaurus.
Read the full article: RRI Study Finds Accretion Disk Around Pulsar Centaurus X-3
Practice Questions
Scientists of which institute found that the X-ray pulsar Centaurus X-3 accretes matter through an accretion disk?
- A.Indian Institute of Astrophysics
- B.Raman Research Institute
- C.Physical Research Laboratory
- D.Inter-University Centre for Astronomy and Astrophysics
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The group examined four secondary emission lines from the system and concluded that the structure causing those lines to vary must be turning along with the pulsar, which pointed them to the accretion stream and therefore to a disk feeding it.
Read the full explanation →Which structure was identified as the cause of the varying secondary emission lines in Centaurus X-3?
- A.The stellar wind of the companion star
- B.The surface of the neutron star
- C.The accretion stream
- D.A ring of dust around the binary
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The team worked out that the structure responsible had to be rotating together with the pulsar, and the stream fits that description: as it swings between the pulsar and the observing satellite, the direct radiation from the pulsar weakens while the light re-emitted by the stream strengthens, producing the variation…
Read the full explanation →At APAC 23, which platform has been created specifically for mobility start-ups?
- A.Technology Theatre
- B.Exposition
- C.TechHive
- D.Digital Twin Pavilion
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The correct answer is TechHive, described as a dedicated platform created to connect mobility start-ups with the wider automotive ecosystem, where emerging companies can show their innovations and meet industry leaders, technology experts, investors, possible customers and collaborators.
Read the full explanation →In which year did the APAC conference series begin, under the name International Pacific Conference?
- A.1971
- B.1981
- C.1991
- D.2001
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The series started in that year as the International Pacific Conference and has since grown into a collaborative automotive engineering forum representing 11 countries across the Asia-Pacific region.
Read the full explanation →Where and when will APAC 23 be held?
- A.Bharat Mandapam, New Delhi, 13-14 November 2026
- B.Yashobhoomi Convention Centre, New Delhi, 13-14 November 2026
- C.Pragati Maidan, New Delhi, 3-4 December 2026
- D.Chennai Trade Centre, 13-14 November 2026
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The two-day conference will bring the Asia-Pacific mobility engineering community together at that venue.
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