10 most difficult space riddlesSpace quiz
A star that pulsates radially, changing both diameter and temperature is called a ...
A Cepheid variable is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude. A strong direct relationship between a Cepheid variable's luminosity and pulsation period established Cepheids as important indicators of cosmic benchmarks for scaling galactic and extragalactic distances.
What is the second brightest star in the night time sky, after Sirius?
Canopus is the brightest star in the southern constellation of Carina, and the second brightest star in the night time sky, after Sirius. Its name is generally considered to originate from the mythological Canopus, who was a navigator for Menelaus, king of Sparta.
Which rover was the first to explore Mars?
Sojourner was the first Mars rover. It was much smaller than Curiosity, whose wheel is about the size of the whole Sojourner. It landed on July 4, 1997 as part of the Mars Pathfinder mission on Mars's Ares Vallis and remained in contact with Earth till September 27, 1997.
Which of the following cosmic structures is the largest?
Galaxy filaments are the largest known structures in the universe. They group galaxy superclusters, which in turn are formed by cluster composed of galaxies. Hercules–Corona Borealis Great Wall is considered the largest known structure of Universe. It is estimated to span 10 billions light years.
What astronomical object emerges sometimes from supernova instead of a black hole?
only a black hole can emerge from supernova
A magnetar is a type of neutron star with an extremely powerful magnetic field. The magnetic field decay powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays. As of March 2016, only 23 magnetars are known, with six more candidates awaiting confirmation.
What is the largest discovered star? (by radius)
VY Canis Majoris
UY Scuti is a bright red supergiant and pulsating variable star in the constellation Scutum. It is currently the largest known star by radius and is also one of the most luminous of its kind. It has an estimated radius of 1,708 solar radii (1.188×109 kilometres; 7.94 astronomical units); thus a volume nearly 5 billion times that of the Sun. It is approximately 2.9 kiloparsecs (9,500 light-years) from Earth. If placed at the center of the Solar System, its photosphere would at least engulf the orbit of Jupiter.
The idea that the nascent universe passes through the phase of exponential expansion, which was driven by the positive density of vacuum energy, is called;
Grand unification theory
Theory of Supersymmetry
All answers are correct.
Alan Guth formally proposed the idea of cosmic inflation in 1981, the idea that the nascent universe passed through a phase of exponential expansion that was driven by a positive vacuum energy density (negative vacuum pressure).
What is the source of the fast radio burst (FRB)?
its source is unknown
A fast radio burst (FRB) is a high-energy astrophysical phenomenon manifested as a transient radio pulse lasting a few milliseconds on average. The origin of the FRBs has yet to be determined. Proposals range from a rapidly rotating neutron star and a black hole to an extraterrestrial intelligence.