What is the mass of the black hole at the center of our galaxy
if a star orbiting 0.0025 pc away has an orbital period of 7 years?
Be careful of units here.
The supermassive black hole in the center of the Milky Way has a
mass of roughly 3 million M⊙and the Milky Way is approximately10
billion years old. Estimate the average amount of matter accreted
by the black hole per year since that time and use that information
to propose modes by which the black hole has grown. That is, make
some simple models which describe what the black hole might have
eaten, and how much it has eaten as a...
In April 2019, the Event Horizon Telescope
collaboration announced that it had made the first spatially
resolved images of a black hole, specifically the supermassive
black hole in the center of the M87 galaxy. Using a wavelength of
1.3 mm, the EHT managed to achieve a resolution of approximately
1.2 x 10-10 radians.a) What is the diameter of the primary aperture of the
EHT? How does this compare to the diameter of the
Earth?b) Research the Event Horizon Telescope and...
Which of these are actual evidence for the existence of a black
hole in the center of the Milky Way, and which are not?
Stars are observed to disappear into the black hole
Bright quasar emission is detected from the center of the
galaxy
Telescopes have been used to take high resolution images of the
black hole's event horizon
Astronomers observe an extremely bright and compact radio
source
The closest approach of stellar orbits near the center of the
galaxy...
1. What is the evidence for a black hole at the center of the
Milky Way? How does this compare to stellar size blackholes? How
can these smaller blackholes be observed?
2. What is Hubble’s Law? In what situations does Hubble’s Law
not apply?
3. What is the cosmic microwave background? What is its
origin?
The singularity at the center of a black hole is predicted to be
a region of zero volume and infinite density that contains all of
the black hole's mass. It is a point at which all currently known
physical laws break down. Yet in a black hole, this "terrible
point" is hidden from view behind an event horizon that prevents
any knowledge about the singularity reaching the outside universe.
Astronomers continue to spend considerable effort trying to
understand the nature...
Multiple choice: The presence of a black hole in a galaxy core
can be inferred from (a) the total mass of the galaxy; (b) the
speeds of stars near the core; (c) the color of the galaxy; (d) the
distance of the galaxy from the Milky Way Galaxy; or (e) the
diminished brightness of starlight in the galaxy core, relative to
surrounding areas.
Multiple choice: Which one of the following statements about
black holes is false? (a) Inside a black...
A The U.S.S. Enterprise (NCC‑1701) approaches an unknown system
with a Black Hole at the center. One of the planets in this system
is observed to have an orbit with a radius of R1 = 3.5
AU and a period of T1 = 0.7 years. What is the mass of
the Black Hole compared to the mass of the Sun?
The mass of the Black Hole, MBH =
Another planet in the system is observed to have an orbital
radius...
A Black Hole has an event horizon, located at the Schwartzschild
radius from the center of the black hole. The Schwartzschild radius
of a black hole is proportional to its mass. We can write a handy
version of this equation for stars in terms of Solar Masses as
follows: R = 3M
Where R is measured in kilometers and M in Solar Masses. So a 1
solar mass object (the Sun for example) if turned into a black hole
would...