Astro Final Exam

If we reverse the expansion of the universe and ask when all of the material in the universe was in the same location, the age of the universe can be determined. According to Phil the current, best estimate for the age of the universe is (the value has been updated slightly since the video was recorded but is close to this value) 4.76 Billion years 10.21 Billion years 13.82 Billion years 46.75 Billion years 11.05 Billion Years

13.82 Billion years

pulsar

A rotating, magnetized neutron star whose radio waves periodically sweep across Earth, producing emission patterns that are observed as bursts of energy.

neutron star

A stellar remnant supported by neutron degeneracy pressure that results from the gravitational collapse of a massive star.

Type Ia Supernova

A supernova occurring after a white dwarf accretes enough mass from a companion star to exceed the Chandrasekhar limit.

Muon

An elementary, extremely short-lived particle that is heavier than a electron

Pulsating stars, that change their brightness with a regular period are known as ____________. They were important for determining the distance to galaxies because their period is related to their luminosity (L). pulsars neutron stars Cepheid variables. novae supernovae

Cepheid variables.

Active galaxies are notable because they are point sources that emit extremely energetic streams of gamma ray photons x-ray photons infrared photons visible light photons Either a. or b.

Either a. or b.

These galaxies are characterized by a lack of gas and dust and are primarily made of older stars. They range in size from a few thousand light years across to vastly larger than the Milky Way. Spiral Elliptical Irregular Peculiar Toroidal

Elliptical

According to Phil, where is the center of the universe? The supermassive black hole at the center of the Milky Way galaxy The Virgo supercluster of galaxies The center of mass of the Local Group of galaxies Every point in the universe looks like the center, so no point is actually the center of the universe The center is approximately 35,000,000 LY from us in the direction of the constellation Cameleopardis.

Every point in the universe looks like the center, so no point is actually the center of the universe

This scientist was the first to declare that the universe was NOT static and unchanging, but either expanding or contracting. Albert Einstein George Lemaitre Vesto Slipher Annie Cannon Stephen Hawking

George Lemaitre

In 1920, the Great Debate was an argument about whether the the Milky Way was the entire universe, or if the Milky Way was one of many similar type of objects. Who was the astronomer who argued that the Milky Way was all there is? Harlow Shapley Heber Curtis Edwin Hubble Annie Cannon Subrahmanyan Chandrasekhar

Harlow Shapley

These galaxies have odd or distorted shapes and are all due to collisions between galaxies that are still occuring. Spiral Elliptical Peculiar Irregular Toroidal

Irregular

Where would you find the Milkomeda Galaxy? It is a member of the Virgo Supercluster It is a satellite galaxy of the Andromeda Galaxy It doesn't exist yet. It will be the galaxy that forms when the Milky Way and Andromeda Galaxies merge It is a member of the Leo Group It is a member of the Ursa Major Group

It doesn't exist yet. It will be the galaxy that forms when the Milky Way and Andromeda Galaxies merge

The small cluster of galaxies that the Milky Way is a part of (a few dozen in all) is known as the Family Group Local Group Cluster Group Related Cluster Family Cluster

Local Group

Stellar Ejecta

Material expelled in a stellar explosion such as a supernova

The Greek word Galaxius means Broad river Huge river Milky Clean Humongous

Milky

What is the universe expanding into? Nothing, it is creating spacetime as it expands Another universe The superuniverse The ether, which actually pervades all of spacetime as well A black hole

Nothing, it is creating spacetime as it expands

thermonuclear runaway

Nuclear burning that ignites and spreads catastrophically, consuming all available fuel.

Mizar and Alcor (also called the horse and rider) have been known since ancient times. Which of the following statements is NOT true about them. They are held together with a force of gravity. One of the stars will be exploding (supernova) soon. They are a multiple star system with a total of six stars orbiting each other. They were once used as a vision test. They are found in the Big Dipper.

One of the stars will be exploding (supernova) soon

Our sun is thought to be on a small projection from one of the major arms of the Milky Way Galaxy, called the Persueus Arm Outer Arm Sagittarius Arm Orion Arm Norma Arm

Orion Arm

When multiple star systems are first formed, they may not be fully stable, causing one or more stars to eventually be ejected. Only the stable arrangements survive for a long period of time. Which of the following stars does Phil say "might have" had a companion but we will never really know Rigel Polaris Our sun Betelgeuse Arcturus

Our sun

helium flash

Rapid internal ignition of helium fusion in the core of an evolved star.

How do we know that there is a supermassive black hole at the center of the milky way?

Sagittarius a star, stars are looping around

Clusters of galaxies clump together to form larger structures known as ________________ which are held together by their mutual gravitational attraction. Galaxy spheres Galaxy neighborhoods Superclusters Supergroups Gravitational webs

Superclusters

The astronomer named Vesto Slipher who according to Phil has the "uncontested, coolest name for an astronomer", began in 1912 abserving the spectra of spiral galaxies and by 1917 had observed 25 of them. What was the remarkable discovery that he made? The galaxies were highly blue shifted indicating the galaxies were rapidly approaching our galaxy. The galaxies had supermassive black holes at their centers emitting x-rays. The galaxies had masses from 10-100 times the mass of the Milky Way galaxy. The galaxies were highly red shifted indicating the galaxies were rapidly moving away from our galaxy. The galaxies showed very little metal in their spectra indicating that they are made of Population II stars.

The galaxies were highly red shifted indicating the galaxies were rapidly moving away from our galaxy.

Type II Supernova

The rapid collapse and violent explosion of a massive star.

When galaxies collide, what is the most likely outcome? One will be ripped apart by tidal forces and the other will become more compact They will eventually merge to form a single galaxy The smaller galasy will grow while the larger galaxy will shrink until they have approximately the same mass The galaxies will orbit each other for several billion years before separating and continuing on their original paths The stars and the gas clouds can pass of one galaxy can pass right through the stars and dust clouds of the other galaxy so no collision is likely to occur

They will eventually merge to form a single galaxy

All of the following are types of galaxies except Elliptical Spiral Irregular Peculiar Toroidal

Toroidal

The Tarantula Nebula is forming so many stars that astronomers think it may be forming a globular cluster a new galaxy a supermassive black hole an open cluster

a globular cluster

The supermassive black hole at the center of the Milky Way does not appear to be emitting light but is virtually invisible to us. This black hole without an accretion disk is called an infant black hole a mature black hole a quiescent black hole an active galaxy a naked black hole

a quiescent black hole

A spiral galaxy can grow by making more stars supernovae converting hydrogen into heavier elements absorbing smaller galaxies fling some stars awy from the center and some stars toward the center of the galaxy

absorbing smaller galaxies

A region near a black hole has matter orbiting the black hole at nearly the speed of light and is heated from friction and other interactions. This region is reaches temperatures of millions of degrees and consequently emits a huge amount of light across the spectrum. event horizon singularity accretion disk halo region photosphere

accretion disk

In the 1960s the object known as 3C273 appeared with optical telescopes to be a dim blue object, but extremely bright in the radio part of the spectrum. It was determined from its spectra to be a normal blue star a pulsar with a red giant companion about 50 light years away a supernova remanant about 150,000 light years away a cool, but relatively close star cluster an entire galaxy more than 2 billion light years away

an entire galaxy more than 2 billion light years away

Two huge, looping streams of stars circling the Milky Way are probably part of the Sagittarius and Canis Majoris galaxies pulling material out of the Milky Way being eaten by the Milky Way passing by like a comet past our solar system were ripped apart by the Andromeda Galaxy before orbiting the Milky Way and will merge to form a "moon" or daughter galaxy around the Milky Way

being eaten by the Milky Way

The study of the large scale structure of the universe is called grand astrology cycadian astronomy cosmology cosmetology bangology

cosmology

Mass of a large star

greater than 20 solar masses

The Hubble "Deep Field" image was taken in the 1990s of one of the darkest areas of the sky. It observed a small spot of the sky about 2.6 arcminutes on a side (about the size of a grain of sand held in your hand at arm's length) and took a picture over the course of ten days. When the picture was analyzed they found it was mostly empty space it contained hundreds of stars it countained millions of stars it contained thousands of galaxies it was full of glowing dust

it contained thousands of galaxies

As we observe more and more distant objects, the time the light takes to get to us is longer and longer. This means that we are seeing the object as it appeared in the past. The astronomical term for this is past time future time cosmological time lookback time red shift time

lookback time

The Big Bang must have been very hot, so hot that there would be a lot of visible light produced. Because of the expansion of the universe, this visible light has been red shifted to the ______________ range of the electromagnetic spectrum. Penzias and Wilson were awarded the Nobel prize in physics (1978) for their serendipitous discovery of this radiation in 1965. ultraviolet infrared red visible microwave x-ray

microwave

Which of the following elements were created in the Big Bang? only hydrogen (100% H) only helium (100% He) mostly hydrogen and helium (75% H and 25% He) all the elements were created in their current abundance in the Big Bang The Big Bang was so hot that even after 380,000 years no elements could be created

mostly hydrogen and helium (75% H and 25% He)

The gases expelled by a low mass star in its red giant phase don't get very far (about 1 light year or so) by the time the star collapses to form a white dwarf. When the radiation excites the gases, they glow and we call them a ionization cluster planetary nebula protostar neutron star black hole

planetary nebula

A quasi-stellar radio source is now more commonly called a pulsar magnetar neutron star quasar supernova

quasar

The Large Magellanic Cloud and Small Magellanic Cloud are considered _______________ of the Milky Way Galaxy. partner galaxies sibling galaxies sire galaxies daughter galazies satellite galaxies

satellite galaxies

What do astronomers now think powers active galaxies? stellar mass black holes supermassive black holes co-orbiting neutron stars binary neutron stars binary red supergiant stars

supermassive black holes

One possible explanation for the weird, beautiful and fantastic shapes of planetary nebulae is that they spun faster at first then slowed as material was ejected swallowed some their planets which then stirred the interiors of the stars rotate faster at the equator than the poles, causing material to be flung away from the equator faster are affected somehow by the intense magnetic field of their star are caused by the precession of the axis of the star

swallowed some their planets which then stirred the interiors of the stars

Edwin Hubble and (partner) carefully studied the galaxies that had been studied by Slipher and concluded that the further away a galaxy was from us, the faster it was receding from us. the slower it was receding from us. the more likely it was to not be moving relative to us. the more likely it was to be made up of larger mass stars. the more likely it was to be made of younger, metal rich stars.

the faster it was receding from us.

Chandrasekhar limit

The maximum mass (1.4 MSun) of a white dwarf; the mass that can be supported by electron degeneracy pressure.

Roche lobe

The region around a star within which orbiting material is gravitationally bound to that star.

Spagettification

The theory that you will become a long, thin noodle, kilometers in length, but narrower than a hair wide.

Optical Double Stars are two or more stars that appear next to each other in the sky. Which of the following statements is true about them? They are never binary stars. They could be close together in space, but more carfeul observation is needed to determine if they are. They are always close together in space. They are never close together in space. They are temporarily bound together with a gravitational force.

They could be close together in space, but more carfeul observation is needed to determine if they are.

On August 17, 2017 the LIGO detectors in the US and the Virgo detector in Italy detected a seismic wave on the lunar surface. a seismic wave on the Martian surface. a seismic wave beneath the Martian surface. a disturbance in spacetime called a gravitational wave.

a disturbance in spacetime called a gravitational wave.

One of the primary reasons that kilonvoae have not ever been seen is that they fade very quickly in only a few hours. a few months. a few minutes. a few days. a few years.

a few days.

If you could magnify an atom to be 100 meters across (the size of a football field), then the nucleus would be about the size of a baseball a football a grain of sand a basketball a marble

a marble

hydrogen shell burning

beginning of the red giant phase, the fusion of hydrogen in a shell surrounding a stellar core that may be either degenerate or fusing more massive elements

A star with a mass between 8 and 20 solar masses will undergo nuclear fusion in the core all the way up to iron (Fe) before exploding in a supernova explosion. If the remaining core mass is more than 1.4 solar masses and less than 2.8 solar masses then this incredibly dense object will form. a.proton star b.black hole c.neutron star d.white dwarf e.electron star

c neutron star

Messier Objects

comet hunter made a catalog of objects that could be confused with comets, includes star clusters, nebulae, and other galaxies

In March 2011, a star which wandered in too close to a black hole was swallowed up in one quick gulp completely unaffected by the black hole flung out of its ogalaxy into intergalactic space pulled apart to make two smaller stars which now orbit the black hole completely ripped apart and briefly flared to be as bright as a trillion suns

completely ripped apart and briefly flared to be as bright as a trillion suns

electron degeneracy pressure

degeneracy pressure exerted by electrons, as in brown dwarfs and white dwarfs

neutron degeneracy pressure

degeneracy pressure exerted by neutrons, as in neutron stars

relative velocity

describes the velocity of an object with respect to a frame of reference

When the Las Cumbres Observatory (LCO) began looking for the kilonova, they had preprogrammed galaxies to look at. Which galaxy was the kilovova located in? third! first! fourth! fifth! second!

fifth!

At the exact same time that LIGO and Virgo had their detections, NASA's Fermi satellite detected radio waves. sound waves. gamma rays. a neutrino pulse.

gamma rays.

Measuring the Doppler shift of radio waves emitted in a narrow band by young star-forming regions allowed us to "see" that the Milky Way is very dusty is made of metal-rich stars has spiral arms is collapsing is expanding

has spiral arms

why is the event horizon the edge of a black hole?

if u get closer nothing can escape, the edge

Gravitational waves are

ripples in space-time that can be produced by two orbiting black holes

How is matter lost in the giant or supergiant stages of a star?

very far away from the center, the giant will blow it away in shells, shells of material will leave results in planteary nebula

How are we able to see most black holes?

we see the accretion disk

According to Phil, the only way we know how to get accurate stellar masses is when they are incredibly dim when they are in a binary system when they have iron absorption lines when they have hydrogen absorption lines when they are incredibly bright

when they are in a binary system

The most bizarre binary system that Phil knows about is 4U 1820-30 which orbit each other with a period of only 685 seconds (11.4 minutes) and is composed of a neutron star and a blue supergiant red giant red supergiant white dwarf yellow dwarf

white dwarf

Mass of a medium star

8 - 20 solar masses

tidal forces

the differences in gravity in a body being attracted to another body

Postulates of Special Relativity

1. The laws of nature are the same for everyone. 2. The speed of light is the same for everyone.

What would we see if we saw someone fall into a black hole while holding a laser?

1. time between the blinks will stretch out, not as often 2. violet color will become red-shifted

How does the final mass of a star lead to either a white dwarf, neutron star, or black hole?

1.4 white dwarf, 1.4-2.3 neutron star, 2.3 black hole

According to Phil, our solar system is located near the center of the Milky Way at the outer rim of the Milky Way about 1/2 of the way from the center to the edge of the Milk Way about 3/4 of the way from the center to the edge of the Milk Way about 1/4 of the way from the center to the edge of the Milk Way

about 1/2 of the way from the center to the edge of the Milk Way

The density of neutron stars matter, neutronium, is about 400 million metric tons per cubic inch. Phil tells us this is like squishing _________________ into one single six-sided die. all of the automobiles in China all of the automobiles in North America all of the people on Earth all of the automobiles on the entire Earth all of the water on Earth

all of the automobiles in North America

What happens when a white dwarf steals enough mass from its companion to exceed 1.4 solar masses? It will become a red giant. it releases a large amount of energy called a nova and then can collect more mass. It will collapse and form a black hole. it fuses nearly all of its carbon at once and becomes a supernova. It will split into two smaller stars, about 0.7 solar masses each.

it fuses nearly all of its carbon at once and becomes a supernova.

impact of mass on an object as it approaches the speed of light

mass gets bigger

About how far can we see before intstellar dust begins to block our view of the stars? 25 light years 550 light years 1000 light years 50,000 light years 100 light years

1000 light years

How far away was the kilonova event? 130 trillion ly from Earth. 1.3 ly from Earth. 130 billion ly from Earth. 130 million ly from Earth. 130 ly from Earth

130 million ly from Earth.

supermassive black hole

A black hole of millions or billions of solar masses that is found in the center of a galaxy.

Kilonova

occurs in a compact binary system when two neutron stars or a neutron star and a black hole merge into each other

cosmic rays

A high-speed subatomic particle (atomic nucleus) from space.

rest mass

mass of an object when it is at rest relative to the observer

A neutron star has more mass than the sun, but is packed into an object only 1 mile wide. 10000 miles wide. 10 miles wide. 100 miles wide. 1000 miles wide.

10 miles wide.

The Milky Way Galaxy is a spiral galaxy with a disk shape whose dimensions are 100,000 light years across and 100,000 light years thick 50,000 light years across and 100,000 light years thick 100,000 light years across and 50,000 light years thick 100,000 light years across and several thousand light years thick 100,000 light years across and 10 light years thick

100,000 light years across and several thousand light years thick

A magnetar has incredibly powerful magnetic fields. as much as a quadrillion times the magnetic field strength of our sun. Occasionally these will have star quakes, like earthquakes that can release energy in a flare a trillion times stronger than a typical solar flare. The amount of energy released in one of these events is the same as the sun releases in 1,000 years 250,000 years 250 years 2.5 Million years 50 year

250,00 years

The escape velocity of the Earth is about 11 km/s. The sun has an escape velocity of 600 km/s. A neutron star can have an escape velocity of 150,000 km/s. What is the escape velocity at the event horizon of a black hole? 600,000 km/s (2x the speed of light) 300,000 km/s (the speed of light) 450,000 km/s (1.5x the speed of light) 150,000 km/s 200,000 km/s

300,000 km/s (the speed of light)

At the center of the Milky Way Galaxy is a supermassive black hole with a mass of 2.5 Million Solar Masses 2.2 Million Solar Masses 2.75 Million Solar Masses 10 Million Solar Masses 4.0 Million Solar Masses

4.0 Million Solar Masses

It wont happen on its own, but in order to form a black hole with a star the mass of our sun, it would need to be compressed to a diameter of only 6 km 100 km 50 km 60 km 20 km

6 km

gravitational lensing

A change in the path of light passing a massive object produced by the curvature of space-time.

red giant

A cool star with a large radius that has evolved off the main sequence because hydrogen fuel in its core is depleted.

Supernova Light Curves

A graph of the light output versus time of an astronomical object.

space-time

A unified, four dimensional geometry of the Universe that incorporates both space and time.

general theory of relativity

Albert Einstein's second theory of relativity, which extends the special theory of relativity by incorporating gravity and states that matter and energy tell space-time how to curve while space-time tells matter and energy how to move.

According to Wikipedia - Stellar Nucleosynthesis (Links to an external site.), all of the following are produced in a kilonova explosion EXCEPT Uranium (U) Platinum (Pt) Silver (Ag) Aluminum (Al) Gold (Au)

Aluminum (Al)

planetary nebula

An evolutionary stage for low- and intermediate-mass stars that comes between the AGB and white dwarf phases, in which stellar wind material is driven off the hot star and ionized.

Refrence frame

An individual perspective from which observations are made.

What will happen to the Earth when the sun becomes a black hole? it will drift away from the sun due to the weakening of the gravitational field Bad question. The sun will never be able to form a black hole it will get a little closer because the light from the sun will no longer be pushing on it It will be sucked in because of the sun's increased gravitational field It will continue to orbit the black hole at its current radius

Bad question. The sun will never be able to form a black hole

Which one of the following types of binaries would best be studied by watching the light curve of the system (the total light from the system). Eclipsing binary. Visual binary. Spectroscopic binary.

Eclipsing binary.

special theory of relativity

Einstein's theory that no particle of matter can move faster than the speed of light and that motion can be measured only relative to a particular observer

When ancient people looked up at the Milky Way, they saw a glow that looks like a nebula. Which of the following astronomers looked with a telescope and descovered that the Milky Way is made of countless stars, so close together that they could not be seen as separate with the naked eye. Galileo Galilee Christian Huygens Edwin Hubble Edmond Halley William Herschel

Galileo Galilee

When light escapes from a black hole, it appears to lose energy. This is known as Doppler redshift Gravitational redshift conservation of energy Gravitational blueshift Doppler blueshift

Gravitational redshift

What makes the Las Cumbres Observatory better than most ground based telescopes? The telescope is four times the size of the Keck observatory. They have the highest resolution cameras in the world. It is a network of telescopes around the globe that always has at least one telescope in the dark. The telescope is at the top of La Cumbre peak. The cameras are sensitive to both infrared and x-ray light.

It is a network of telescopes around the globe that always has at least one telescope in the dark.

nova

Nonterminal explosive nuclear fusion occurring on the surface of a white dwarf after it has accreted matter from a companion star.

If a pair of binary stars are so close together that we cannot see them as separate even with the largest telescope, then we can use spectroscopy to determine that two or more stars are present. Spectroscopic binaries rely on which of the following principles to distinguish the two stars. The light of the dimmer star is blue-shifted when it is behind the brighter star and red-shifted when it is in front of the brighter star. The Doppler effect. One of the stars will be moving away and its light red-shifted, while one will be moving toward us and its light will be blue-shifted. The light of the brighter star is dimmed when the other star passes in front of it. The Doppler effect. Both of the stars will be red-shifted or blue-shifted depending on how the Earth is moving. Take a photo of it and use digital zoom until we can finally see them as separate.

The Doppler effect. One of the stars will be moving away and its light red-shifted, while one will be moving toward us and its light will be blue-shifted.

singularity

The central point of a black hole, where density and space-time curvature is infinite.

If we study the light curve, we can see that the dips in brightness are not always the same "depth". What is the cause for a deeper dip? The larger star is hotter and is passing in front of the cooler, smaller star. The stars vary in brightness and the deeper dip corresponds to a decrease in the overall brightness of the system. The larger star is cooler and is passing behind the smaller hotter star. The hotter star passes in front of the cooler star. The cooler star passes in front of the hotter star.

The cooler star passes in front of the hotter star.

event horizon or schwarzschild radius

The distance from a black-hole singularity where the escape velocity equals the speed of light

time dilation

The effect of relativity in which time runs slower for objects near a strong gravitational source or for objects that are moving at relativistic speeds in the reference frame of distant observers.

The brightest star in the night sky, Sirius, has a very faint companion star that can be seen with a telescope. Which of the following telescopes can see the binary actually appear as brighter than Sirius? X-ray telescope Radio telescope Ultraviolet telescope Microwave telescope Visible light telescope

X-ray telescope

weak nuclear force

a powerful attractive force that acts over a short range

black hole

a region of space having a gravitational field so intense that no matter, radiation or light can escape.

A neutron star packs a mass of more than our sun into the size of the state of Arizona a basketball the North American Continent c.a small city the planet Earth

a small city

Twin Paradox

a thought experiment in special relativity involving identical twins, one of whom makes a journey into space in a high-speed rocket and returns home to find that the twin who remained on Earth has aged more.

The "guest star" of 1054 AD, whose appearance was recorded in the Chinese records but not in European ones, was what we now know as a

crab nebula, messier 1

What happened on August 17, 2017 that changed astronomy forever?

kilonova

Mass of a small star

less than 8 solar masses

The new field of "multi-messenger astronomy" refers to the idea that we get information from both ultraviolet and infrared light. light and gravitational waves. sound and light. sound and gravitationaly waves. light and cosmic rays.

light and gravitational waves.

When a neutron star is formed, this force is strong enough to oppose the incredibly strong force of gravity trying to collapse it further. electron degeneracy pressure proton degeneracy pressure radiation pressure neutron degeneracy pressure neutrino pressure

neutron degeneracy pressure

If a supernova remnant core has a mass greater than 2.8 solar masses, then what force will be able to stop gravity from collapsing the core? neutrino degeneracy pressure electron degeneracy pressure radiation pressure neutron degeneracy pressure nothing; it is not possible to stop gravity in this case

nothing; it is not possible to stop gravity in this case

As a graduate student, Jocelyn Bell Burnell (and her advisor Antony Hewish who ultimately received a Nobel Prize for this work in 1974) is credited with the discovery of the first rapidly rotating neutron star, which she detected with a radio telescope array. The rapid rotation, together with the powerful magnetic field produces twin beams of energy whcih radiate away from the object. We call this a hydrodynamic engine cosmic spinner spinor pulsar rotator

pulsar

Conservation of momentum is a law of physics that says that if a star is rotating before it collapses, then when it collapses it will stop rotating rotate slower after the collapse continue rotating at the same rate rotate faster after the collapse change its axis of rotation after the collapse

rotate faster after the collapse

If you were to fall feet first into a 10 solar mass black hole, the tidal forces would affect your head more than your feet flatten you like a piece of paper compress you into a tiny sphere spaghettify you squeeze you like a lemon

spaghettify you

A black hole with a mass between 3 solar masses and 12 (it could be more than this though) solar masses is considered to be a primordial black hole dwarf black hole Kerr black hole supermassive black hole stellar black hole

stellar black hole

At the core of nearly every galaxy is higher mass black hole. The first one that was conclusively observed is the one at the center of the Milky Way with a mass of more than 4 million solar masses. These black holes at the centers of glaxies are known as a supermassive black hole dwarf black hole primordial black hole Kerr black hole stellar black hole

supermassive black hole

Most of the globular clusters in the Milky Way are found in the galactic disk the galactic bar or bulge the galactic halo a ring around the edge of the Milky Way the Andromeda Galaxy

the galactic halo

The region surrounding the Milky Way out to about 100,000 light years is made up of old, stable red dwarf stars and NO star-forming regions is called the halo the stellar graveyard the stellar nursery the hat the bowl

the halo

gravitational redshift

the redshift of photons leaving the gravitational field of any massive object, such as a star or black hole

According to Einstein's theory of general relativity, the force that we perceive to be gravity is really just the warping of the fabric of spacetime. The presence of mass causes this fabric to be warped and the larger the mass, the more it warps spacetime. The strange thing is that time will not pass the same for people in different gravitational fields, according to an outside observer. The greater the warping of spacetime (the stronger the gravitational field) the slower the clocks will appear to tick does not matter; clocks will always tick in the same way the faster the clocks will appear to tick

the slower the clocks will appear to tick

What happens when protons and electrons are pushed together under extreme pressures? they merge and form a negatively charged neutron they form a positively charged prion they form a positron electron pair plus two neutrinos they annihilate each other and release light energy they merge and form a neutral neutron

they merge and from a neutral neutron

A kilonova is 1000 times as powerful as a nova and is a cataclysmic explosion from the merger of two neutron stars. one white dwarf and one red giant. two white dwarfs. two red giant stars. two black holes.

two neutron stars.