Short-period Oscillations in Super-Soft Novae

After a time, the hydrogen runs out almost completely, and it collapses. New reactions begin to take place in the core and these reactions cause the star to expand rapidly. As the stars begin to deplete their new fuel, they switch to others. New elements are formed in the cores of stars but they become too heavy. The star has reached its end growth. When it reaches the end, a tremendous amount of energy is released and it begins to shed its outer layers, the gravity is too weak hold onto them anymore. Once the layers are removed, in the stars place is a fiery core called a planetary nebula. Eventually, the core runs out of fuel and it collapses. This star is now in a very dense state, and is called a white dwarf. Eventually, the white dwarf cools until it no longer shines. This dead star is called a brown dwarf.More massive stars, however, have more violent ways of dying. Some stars turn it into a supergiant. Supergiant stars are extremely bright, and are extremely large. Supergiant stars cores, can collapse violently and suddenly. This collapse causes a tremendous explosion, called a

One type of supernova has shown scientists that according to the solar system, there are other universes out there, we just don’t know what they look like. According to scientists, supernovae play a key role in distributing elements throughout the universe. Ordinarily when something explodes, there are always random scraps of thing flying everywhere, so when a star explodes, it does the same and it shoots elements and debris everywhere around space. Most of the elements are the core of stars, these elements form to create new stars, and small planets in the solar system and in many other solar systems. Scientists look for supernovas by using advanced telescopes, and items. Some of these telescopes are used to look at other explosions in space beside supernovas. Others are used to study x-rays and gamma rays. Either way, they are all used to study

Next, there are the observations of novae. Novae are stars that show a sudden increase in brightness before returning back to their original

With the 1991 launch of the Hubble Space Telescope (HST), astronomers have been given access to data orders of magnitude more accurate and plentiful. In 2001, Wendy Freedman and other researchers, using data obtained via the HST, calculated the value of H to 72 + 8 [6]. Working with data collected from the Chandra X-Ray Observatory in 2006, researcher Massimiliano Bonamente and his team derived a value for H of 77.6 +14.9, -12.5 [7]. Most recently at the LIGO observatory, the value for H was calculated to be 70.0 +12.0, -8.0

When a massive star, outclassing our own sun by fiat, grows old enough that it’s run out of fuel, it sometimes explodes in a violent reaction releasing the elements necessary for new stars, new planets and systems into the depths of space in a matter of minutes. This process is believed to resemble the big bang itself, and astronomers have just discovered the presence of a chemical called lithium in a nova, and this chemical’s presence is helping us understand the concentration of lithium in stellar phenomena.

After approximately 10 billion years after the star is considered to be a main sequence star, the hydrogen at the center of the core is depleted. This causes the nuclear fusion which had been previously fueling the star to die out. Helium replaces the hydrogen in the core, and the inner core begins to shrink due to gravity. This process speeds up once all the hydrogen is completely used up. The radius of the star has increased

Approximately 1,000 years ago the pattern of mass loss suddenly changed, and the Cat's Eye Nebula started forming inside the dusty shells. It has been expanding ever since, as discernible in comparing Hubble images taken in 1994, 1997, 2000, and 2002. The puzzle is what caused this dramatic change? Many aspects of the process that leads a star to lose its gaseous envelope are still poorly known, and the study of planetary nebulae is one of the few ways to recover information about these last few thousand years in the life of a Sun-like

During the condensing of the star’s core, the neutrinos are able to escape, but the neutrons are squished together so much that their density is the same of an atomic nucleus’ density. A violent explosion happens during this process and its called a “supernova”. To put this into perspective, imagine taking something the size of our sun, if not bigger, and compacting it into an area the size of a city. This is so dense that just a teaspoon of it would weigh about 1 billion tons! Crazy, right?

In late 2001, an amateur astronomer happened upon an uncharacteristically bright object in the Monocerotis constellation (Figure 1). Over the next several months the object went through periods of intense brightness the likes of which had rarely been seen before. My research this summer was to use a computer simulation to better understand what may have caused this strange event known as V838 Mon. In order to understand what may have caused the bright outbursts, it is necessary to try and make a model of the event that caused them. To make this model, we implement a Smoothed Particle Hydrodynamics (SPH) code called Starsmasher. The code calculates the movements of many small particles to replicate the movement of a fluid, such as a liquid or

inant stellar population is comprised of old K/M type stars21 and, partly, also due to the

Type I supernova: star accumulates matter from a nearby neighbour until a runaway nuclear reaction ignites.

Pulsating white dwarf stars are a special subclass of white dwarfs, and they are very useful tools for studying the interiors of stars. As the interior of the white dwarf changes and oscillates, the light signal from the star will pulsate at numerous frequencies. By determining the frequencies at which the star pulsates and using these as boundary conditions in stellar models, astronomers can determine the interior properties of white dwarfs. This summer I was involved in using data from the Whole Earth Telescope and CCD images to determine the frequencies at which two different white dwarf stars pulsate.

Neutron stars are “an incredibly object made of neutron’s, like a giant atomic nucleus.” In the year 1934 two astronomers at CIT made predictions that a collapse of a large star or sun would produce a neutron star. When a star 's mass exceeds roughly 1.4M and has a iron core. It is no longer able to support itself, the core collapse from exponential forces. This is referred to as a type ii supernova or a core-collapse supernova. These newly discovered neutron stars had notable characteristics. A smaller radius of around six miles and masses that were on average between “one and several times the sun”. Neutron stars also had capacity for how large their masses could be, at max it could be two to three solar masses. Although these neutron

Our X-ray sample consists of 124,730 objects from the combination of \textit{ROSAT} All-Sky Survey (RASS) Bright Source Catalog (rass-bsc) and RASS Faint Source Catalog (rass-fsc). RASS is the first all-sky survey in soft X-rays (0.1-2.4 keV), conducted in 1990/91 with ROSAT, a German X-ray telescope satellite~\citep{1999Voges}. The reason that we start the survey with an X-ray catalog is because all galaxy clusters are bright in X-ray from their hot ICM and a central QSO. \corr{We include the bright source catalog because distant cool cores may look like point sources. In addition, according to~\citet{2002Cruddace}, a flux limit for \textit{RASS} for clusters is $3\times10^{-12}\,\rm{erg/s}$, corresponding to $L_{x}=10^{45}\,\rm{erg/s}$ at $z=0.5$.}

The first week of counting and charting was interesting. In the first three days there was a mild dip and the behavior gradually increased in the last four days. On the