Greenbrier Invitational — Astronomy

True or False: Each of the seven major stellar classes in the Morgan-Keenan system have ten subdivisions, allowing for more specific classification.

Which set of stellar classes refers to brown dwarfs?

Which class of main-sequence star has the strongest balmer lines?

Which luminosity class refers to only the brightest and largest stars?

Please explain the difference between the characters "/" and "-" as it refers to stellar classification.

What does the spectral peculiarity designation "z" denote?

The majority of radiation produced by O-type stars falls under what wavelength?

Which star is commonly used as a "standard star" for the stellar class A1V?

The spectra of M-type stars typically contain strong lines of what compound?

Which class of Wolf-Rayet star is the rarest and least populated?

What type of star does the spectral class C refer to, and how do stars obtain this spectral classification?

White dwarfs are commonly given the spectral classification D, which is derived from what term?

What chart is commonly used to find the color of a blackbody given its temperature?

What is the primary source of fusion energy in brown dwarfs?

The proton-proton chain reaction is found mainly in what kind of star?

A helium flash marks the shift of a star from the main sequence to what?

What is the primary composition of population III stars?

What is the major reason behind the lack of stellar formation observed within elliptical galaxies?

The majority of star formation occurs in dense nebulae, which are given the name molecular clouds due to what characteristic?

True or False: Both hot and cold molecular clouds can form stars of all sizes.

Roughly how many molecular clouds are thought to reside within the milky way?

What is the closest area of active star formation to the Solar System?

When a protostar stops accreting gas, it enters what phase of stellar evolution?

T Tauri stars contract to the main sequence along what?

What are the two major sources behind the variability observed in T Tauri stars?

Which of these T Tauri stars is notable for having two actively forming exoplanets?

What is not a source of energy generation for red giants?

What compact object is left behind by a red giant when it dies?

What term refers to the convection of heavier fused elements to the surface of a star?

True or False: Stars of any mass can undergo a red giant phase.

What is the upper mass limit of a white dwarf known as?

What was the first white dwarf to be discovered?

Roughly a third of all known white dwarfs have unusual metal lines within their spectra. Please explain the most likely source of these metal lines.

Planetary nebulas can only form from stars in what mass range?

Approximately what percentage of planetary nebulas are spherically symmetric?

Which of the below is not a current issue plaguing planetary nebula research?

What is the "Mass Gap" as it refers to compact objects?

While the majority of pulsars are mainly visible in radio wavelengths, pulsars powered by accretion are notably bright in what other wavelength?

Over long periods of time, neutron stars can shed rotational energy, a process known as what?

The collision of two neutron stars produces what kind of explosion?

What was the last supernova visible to the naked eye?

The "P" in the supernova typing II-P stands for what?

A supernova caused by thermal runaway includes what type of supernova?

Please describe the term pair instability and describe how it relates to supernova formation.

Cassiopeia A: Give two possible reasons for this significant delay in observation, and explain how they caused it.

Cassiopeia A: What object is the brightest extrasolar emission source in the lower frequencies of the wavelength you provided above?

Ophion Star Family: The researchers behind the discovery developed a unique model to search for young stars relatively close to the Solar System. What is the name of the model they created, and what data catalogue did they apply it to?

Ophion Star Family: What is a possible reason behind this erratic behavior? Please explain how the stars were affected by this.

Helix Nebula — Roughly how many of these can be found within the nebula, and what is their individual mass in solar masses?

Helix Nebula — This star has three commonly used designations. Please list two of them.

Helix Nebula — This central star has a notable excess of mid-infrared emissions. What is the likely source of this emission excess, and what is the composition of this source?

Helix Nebula — This star is an object known as a white dwarf. What is this star's stellar classification, and what does it indicate about the star's properties?

G359.13 — What type of object is this DSO known as?

G359.13 — What objects can be found to the west of each of the kinks, and what are their respective designations?

ZTF J203349.8+322901.1 — There are three possible explanations for this property. Please explain each of them.

Mira — This system is what is known as a symbiotic system, and is actually the closest example of one to the Solar System. Please explain what a symbiotic system is.

Mira — The primary component of this system is the prototype for what type of variable star?

Mira — What is the general behavior exhibited by this type of variable star?

Messier 1 — What is the commonly used name of this central object, and what is its diameter in kilometers?

Messier 1 — This central object will occasionally demonstrate sudden changes in its rotational period, before then returning to normal. What are these sudden changes called, and what are they likely caused by?

Orion Molecular Cloud Complex — True or False: This DSO contains the most active star-forming region within the Milky Way.

Supernova Remnant Shenanigans — Find the distance in parsecs of a supernova remnant with an apparent magnitude of 9, an absolute magnitude of -4.2, and 0.7 magnitudes of light extinction.

Supernova Remnant Shenanigans — Calculate the approximate angular size in arcseconds of this supernova remnant, assuming a physical radius of 2 light years.

Supernova Remnant Shenanigans — A black hole with a mass of 15 solar masses lies at the center of this supernova remnant. Find its Schwarzchild radius in kilometers.

Stellar Characteristics — Calculate the temperature in kelvin of a star with a peak wavelength of 3,267 angstroms.

Stellar Characteristics — What stellar class does this star belong to?

Stellar Characteristics — Assuming a radius of 2 solar radii, find this star's mass in solar masses.

Stellar Characteristics — Calculate the stellar lifetime of this star in years.

Orbital Mechanics — Given an object with an emitted wavelength of 623.2 nm, calculate its approximate velocity in meters per second if its observed wavelength is 619.7 nm.

Orbital Mechanics — Is this object moving towards or away from the observer?

Orbital Mechanics — If this velocity represents the circular velocity of this object's orbit around a 5 solar mass star, calculate its orbital radius in AU. Assume the mass of the orbiting object is negligible.

Orbital Mechanics — Calculate the the orbital period of the object in years.

Orbital Mechanics — Over a 6-month period, this object was observed to change in position by 0.029 arcseconds. Find the distance to this object in light years.