Star formations
What is the relationship between surface temperature and color
when stars are blue they are hotter, and when they are red they are coolest.
Which star lives longer: a 1 solar mass star or a 10 solar mass star?
the lower the mass the longer the lifespan, and cool red dwarfs live the longest
When is your second test?
March 25/26
define protostar
a contracting mass of gas which represents an early stage in the formation of a star, before nucleosynthesis has begun.
identify the process when light atomic nuclei come together to form a heavier one, mass is lost and energy is released.
Give the equation for converting mass into energy
E=mc^2
Describe and differentiate the different kinds of binary stars.
Visible binary, where we can see the stars as we are not on the same plane.
Eclipsing binary when the stars pass in front of each other because we are on the same plane as them.
25%
when do we classify stars as officially born?
when they can sustain themselves on the energy from their own nuclear fusion.
What do we call the process of energy being produced by breaking up heavy atomic nuclei into lighter ones. Hint this does not occur in stars
nuclear fission.
Which are the main competing forces in the star formation process?
gravity and pressure. The force of gravity, pulling inward, tries to make a star collapse. Internal pressure produced by the motions of the gas atoms, pushing outward, tries to force the star to expand.
What is an open cluster of stars?
Open Clusters Open clusters are found in the disk of the Galaxy. They have a range of ages, some as old as, or even older than, our Sun. The youngest open clusters are still associated with the interstellar matter from which they formed. Open clusters are smaller than globular clusters, usually having diameters of less than 30 light-years, and they typically contain only several dozen to several hundreds of stars. The stars in open clusters usually appear well separated from one another, even in the central regions, which explains why they are called “open.”
list the spectral types of the HR diagram in order
O, B, A, F, G, K, M
How far is one AU
the distance from the earth to the sun, or about 93 million miles.
How long do we estimate the sun will live for
12 billion years
When can stars officially be placed on the Main sequence of the HR diagram ?
when they have begun to fuse hydrogen
What do we call objects that never become large enough to begin fusing hydrogen?
Brown dwarfs.
Define sunspots
They are large, dark features seen on the surface of the Sun caused by increased magnetic activity. They look darker because the spots are typically at a temperature of about 3800 K, whereas the bright regions that surround them are at about 5800 K.
why do protostars become less luminous as they become stars? hint how do we calculate luminosity?
there surface areas decrease as they become dense enough to capture the escaping heat and its gravity becomes stronger.
How do we classify the star type that is left over after a star has died?
As a white dwarf.
this material shed from a heated red giant is composed of shells of material such as stellar winds and ultraviolet radiation.
what is planetary nebulae
what is the triple alpha process? (Hint and alpha particle is a helium nucleus)
At temperatures of 100 million Kelvin three helium atoms can fuse into a single carbon nucleus.
DOUBLE JEOPARDY
When and where are the office hours of both the LAs?
Charlotte's office hours are from 12:30-2:30 Mondays in Exploratory room 4105.
Alysa's office hours are Wednesday 12:00 pm - 2:00 pm in EXPL 4208.
What spectrum of the light can we use to observe a proto-star in its early stages?
Infrared
Which is the last element that a 1 solar mass star can produce by fusion? And which is the last element fused in a 10 solar mass star?
Carbon and Iron.