The first time that astronomers observed both gravitational waves and electro-magnetic waves from the same event, what they were observing was:
a. the merger of two black holes with masses dozens of times the mass of our Sun
b. a supernova explosion in one of the closest galaxies to us
c. the collapse of an entire cluster of stars into one big black hole
d. the spiraling toward each other of two neutron stars
e. a binary star system where a giant star is overloading a white dwarf with too much material

answer; i believe that the correct answer is (d) a very small amount of mass

technology is the collection of techniques, skills, methods, and processes used in the the merriam-webster learner's dictionary offers a definition of the term: "the use of moreover, these technologies have become so complex that entire fields more recently, modern works of science fiction such as those by philip k.

explanation:

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.