The faintest known white dwarfs have
Mv ~ 16.2
. Age estimates for these stars are in the range 6.5-11 Gyr, with the variation largely due to uncertainty in the core composition.
What is the luminosity of white dwarf?
The cooling process is very slow for white dwarfs. After a billion years the typical white dwarf is down to
0.001 the luminosity of the Sun
.
What is the magnitude of a white dwarf?
A typical white dwarf has a
density of between 10
4
and 10
7
g/cm
3
. White dwarfs are composed of one of the densest forms of matter known, surpassed only by other compact stars such as neutron stars, quark stars (hypothetically), and black holes.
Do white dwarfs have a strong magnetic field?
White dwarfs are not only very dense objects, but they are associated also with fast rotation (see Ref. [3] and references therein) and also strongly magnetized. Observations have shown that
the observed surface magnetic fields in white dwarfs can be so strong as 109 G
[4, 5].
What is the gravity of a white dwarf?
According to NASA, the gravity on the surface of a white dwarf is
350,000 times that of gravity on Earth
. That means a 150-pound (68-kilogram) person on Earth would weigh 50 million pounds (22.7 million kg) on the surface of a white dwarf.
What is a white star?
1 :
a star of spectral type A or F having a moderate surface temperature and a white or yellowish
color. 2a : an annual morning glory (Ipomoea lacunosa) of the southern U.S. with star-shaped leaves and small white or purplish flowers.
What is the closest white dwarf?
At 8.6 light-years away,
Sirius B
is the nearest known white dwarf star to Earth.
How long do white dwarfs live?
A star cluster’s first white dwarfs are born from stars with relatively short main-sequence lives —
about 50 million years
. The progenitor’s life span is neglible when compared to the billions of years its remnants have existed.
What if the sun was a white dwarf?
If you were to form a white dwarf right now, at 20,000 K, and give it 13.8 billion years to cool down (the present age of the Universe), it would cool down by a whopping 40 K:
to 19,960 K
. We’ve got a terribly long time to wait if we want our Sun to cool down to the point where it becomes invisible.
Why are white dwarfs important?
White dwarfs are rich forensic laboratories that
provide links between the history and future evolution of the Milky Way Galaxy
. The structure and composition of white dwarfs contain the records of the final stages of stellar evolution. … UV astronomy is particularly important for the study of white dwarf stars.
Do white dwarfs spin?
White dwarfs are full of charged particles, like most things in the universe. They are also relatively
small and spin pretty quickly
.
Why do you expect neutron stars to have a more powerful magnetic field than a white dwarf?
Why do you expect neutron stars to have powerful magnetic field? When
the star collapses, the magnetic field is squeezed into a smaller volume
, which can make the field as much as a billion times stronger.
What happens to a star’s magnetic field when it becomes a white dwarf?
The merger of two C/O white dwarfs, at least one of which is magnetic, may result in a
star that is both rapidly rotating and highly magnetic
. If the total mass is less than M
Ch
, a massive, magnetic white dwarf may form.
Can you stand on a white dwarf?
White dwarfs are extremely dense stars, and their surface gravity is about 100,000 times as strong as Earth’s. … It would fall unimpeded through your body, carve a channel through your gut, come out through your nether regions, and burrow a hole toward the center of the Earth. Then you’d have to worry about confinement.
Is Sun a white dwarf?
A low or medium mass star (with mass less than about 8 times the mass of our Sun) will become a white dwarf. A typical white dwarf is about
as massive as the Sun
, yet only slightly bigger than the Earth. … In another 5 billion years, the Sun will have used up all the hydrogen in its core.
Are white dwarfs diamonds?
About 900 light-years away, an ancient white dwarf star has cooled into a
crystallized chunk
of carbon — a diamond. But this isn’t just any old diamond hiding in space: It’s the size of Earth, and it’s 11 billion years old.
