Guide to Space Archives

February 15, 2010December 24, 2015 by Jean Tate

Galaxy Names

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Galaxy names come in a bewildering range of forms; from descriptive (e.g. Whirlpool Galaxy, Black Eye Galaxy, The Eyes), to ones that seem to relate to a constellation (e.g. Andromeda Galaxy, Hydra A, Leo I), to ones named after a person (e.g. Stephan’s Quintet, Malin I, Mayall’s Object), to letter+number combinations (e.g. the Messier catalog galaxies such as M33 and M87), to letters+number combinations (e.g. NGC 3115, DDO 185), to impossible-to-remember stings-with-dashes-dots-and-pluses like MCG-06-07-001, 4C37.11, and SDSS J002240.91+143110.4!

And sometimes a galaxy has LOTS of different names, such as M87, Virgo A, NGC 4486, Arp 152, 3C274, IRAS 12282+1240, WMAP J123051+1223 (there’s, like, about another 20!).

However, of the estimated 100 billion galaxies we could observe, with current astronomical facilities, only a few million have names, and most of those are unique (i.e. only one name per galaxy). Of course, almost all the single-name galaxies are little more than faint smudges in an optical or infrared image … and that gives a clue to where the names come from!

Most galaxy names come from the catalog, or catalogs, in which they appear. The catalogs have many sources, but most recent ones have been put together as a key output of a dedicated survey or mission, and the galaxy name reflects that. So, for example, SDSS stands for Sloan Digital Sky Survey (one of the most amazing optical/NIR galaxy surveys of all time), IRAS for InfraRed Astronomy Satellite, DDO for David Dunlap Observatory (where a catalogue of dwarf galaxies was put together), and 4C for 4th Cambridge survey (a radio survey). Some of the older catalogs, or lists, were put together from previously known galaxies, or objects (the Messier list is perhaps the most famous example).

More to explore, on galaxy names. The online dedicated, searchable database NED (NASA/IPAC Extragalactic Database) is astronomers’ essential resource; SEDS’ (Students for the Exploration and Development of Space, hosted by the University of Arizona LPL) Messier galaxy section is amateurs’ favorite; and Galaxy names are identified by a group of letters and numbers. What do they stand for? (Hubblesite).

Universe Today articles on galaxy names? Sure! Here is a small sample: This Where in the Universe Challenge, Astrophoto: NGC 4631 by Bernd Wallner, and Have a Cigar! New Observations of Messier 82.

Astronomy Cast’s Milky Way episode has more on galaxy names; well worth a listen!

Sources: Hubblesite, SDSS, IRAS, DDO, NASA/IPAC

February 15, 2010December 24, 2015 by Fraser Cain

Galaxy Pics

Hubble Observes Infant Stars in Nearby Galaxy

Here are some beautiful galaxy pics. You can even use these as desktop background wallpapers if you like. Just click on an image to see a larger version and then right-click and choose “Set as Desktop Background”.

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This is a picture of a cluster of stars in the nearby satellite galaxy, the Small Magellanic Cloud. These bright young stars are blasting out a bubble of gas and dust with their powerful stellar winds.

This is a Hubble Space Telescope image of the nearby galaxy Centaurus A. The supermassive black hole at the heart of Centaurus A is currently feeding on a smaller galaxy that recently collided. Cosmic collisions like this were common in the early Universe, but they happen less frequently now with more space in between galaxies.

This is a photograph of the galaxy NGC 4526, captured by the Hubble Space Telescope. You can also see a bright star below the galaxy; it’s not a star at all, but a supernova that was imaged as part of this photograph.

This is an image of the galaxy cluster MACS J0717 captured by NASA’s Chandra X-Ray Observatory. The image from Chandra lets astronomers see where large clouds of hot gas are colliding together, heating up to millions of degrees.

This is an artist’s impression of what a galaxy might have looked like in the early Universe, just a billion years after the Big Bang. Stars formed out of the primordial hydrogen left over from the Big Bang, grew large and then detonated as supernovae, seeding the Universe with heavier elements.

We’ve written many articles about galaxies for Universe Today. Here is a story about how many galaxies there are in the Universe, and here is an article about how many galaxies we have discovered.

If you’d like more info on galaxies, check out Hubblesite’s News Releases on Galaxies, and here’s NASA’s Science Page on Galaxies.

We’ve also recorded an episode of Astronomy Cast about galaxies. Listen here, Episode 97: Galaxies.

February 11, 2010December 24, 2015 by Abby Cessna

Albert Einstein Quotes

Einstein and Relativity — Albert Einstein

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People know Albert Einstein as one of the world’s best physicists and a recipient of the Nobel Prize for Physics, but you may not have heard his many quotes. Here are just some of the things the famous scientist said. Unsurprisingly, many of Einstein’s quotes are about thinking for yourself and being rational.

“A person who never made a mistake never tried anything new.”

“Any intelligent fool can make things bigger and more complex… It takes a touch of genius – and a lot of courage to move in the opposite direction.”

“He who joyfully marches to music in rank and file has already earned my contempt. He has been given a large brain by mistake, since for him the spinal cord would suffice.”

“If we knew what it was we were doing, it would not be called research, would it?”

“Intellectual growth should commence at birth and cease only at death.”

“It is a miracle that curiosity survives formal education.”

“Small is the number of people who see with their eyes and think with their minds.”

Einstein did not believe in blind obedience to anybody or anything, including one’s own country. Some of his quotes on this subject include:

“Never do anything against conscience even if the state demands it.”

“Nationalism is an infantile disease. It is the measles of mankind.”

“Nothing is more destructive of respect for the government and the law of the land than passing laws which cannot be enforced.”

He also made a number of observations on the nature of the atomic bomb and gave his opinion on both traditional warfare and nuclear war.

“I am not only a pacifist but a militant pacifist. I am willing to fight for peace. Nothing will end war unless the people themselves refuse to go to war.”

“I do not believe that civilization will be wiped out in a war fought with the atomic bomb. Perhaps two-thirds of the people of the earth will be killed.”

“I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.”

Albert Einstein’s wit and observation of human nature is obvious in some of the quotes, especially the following:

“Only two things are infinite, the universe and human stupidity, and I’m not sure about the former.”

“People love chopping wood. In this activity one immediately sees results.”

“The difference between stupidity and genius is that genius has its limits.”

“The hardest thing to understand in the world is the income tax.”

If you are looking for more quotes from Albert Einstein, you should check out the top ten Einstein quotes and quotes by Albert Einstein.

Universe Today has articles on Einstein’s Theory of Relativity and Einstein still seems to be right.

For more information, take a look at Einstein’s biography and the Einstein archives.

Astronomy Cast has an episode on Einstein’s Theory of General Relativity.

Sources:
Stanford University
Quotations Book

February 7, 2010December 24, 2015 by Jerry Coffey

What Is The Atmosphere?

[/caption]What is the atmosphere? It is only the thing that keeps you from being burned to death every day, helps to bring the rain that our plants need to survive, no to mention it holds the oxygen that you need to breath. Essentially, the atmosphere is is a collection of gases that makes the Earth habitable.

The atmosphere consists of 78% nitrogen, 21% oxygen, 1% water vapor, and a minute amount of other trace gases like argon, and carbon monoxide. All of these gases combine to absorb ultraviolet radiation from the Sun and warm the planet’s surface through heat retention. The mass of the atmosphere is around 5×10¹⁸kg. 75% of the atmospheric mass is within 11 km of the surface. While the atmosphere becomes thinner the higher you go, there is no clear line demarcating the atmosphere from space; however, the Karman line , at 100 km, is often regarded as the boundary between atmosphere and outer space. The effects of reentry can be felt at 120 km.

Over the vast history of Earth there have been three different atmospheres or one that has evolved in three major stages. The first atmosphere came into being as a result of a major rainfall over the entire planet that caused the build up of a major ocean. The second atmosphere began to develop around 2.7 billion years ago. The presence oxygen began to appear apparently from being released by photosynthesizing algae. The third atmosphere came into play when the planet began to stretch its legs, so to speak. Plate tectonics began constantly rearranging the continents about 3.5 billion years ago and helped to shape long-term climate evolution by allowing the transfer of carbon dioxide to large land-based carbonate stores. Free oxygen did not exist until about 1.7 billion years ago and this can be seen with the development of the red beds and the end of the banded iron formations. This signifies a shift from a reducing atmosphere to an oxidizing atmosphere. Oxygen showed major ups and downs until reaching a steady state of more than 15%.

The Earth’s atmosphere performs a couple of cool optical tricks. The blue color of the sky is due to Rayleigh scattering which means as light moves through the atmosphere, most of the longer wavelengths pass straight through. Very little of the red, orange and yellow light is affected by the air; however, much of the shorter wavelength light(blue) is absorbed by the gas molecules. The absorbed blue light is then radiated in every direction. So, no matter where you look, you see the scattered blue light. The atmosphere is also responsible for the aurora borealis. Auroras are caused by the bombardment of solar electrons on oxygen and nitrogen atoms in the atmosphere. The electrons literally excite the oxygen and nitrogen atoms high in the atmosphere to create the beautiful light show we know as an aurora.

The atmosphere is divided into 5 major zones. The troposphere begins at the surface and extends to between 7 km at the poles and 17 km at the equator, with some variation due to weather. The stratosphere extends to about 51 km. The mesosphere extends to about 85 km. Most meteors burn up in this zone of the atmosphere. The thermosphere extends up to between 320 and 380 km. This is where the International Space Station orbits. The temperature here can rise to 1,500 °C. The exosphere is the last bastion of the atmosphere. Here the particles are so far apart that they can travel hundreds of km without colliding with one another. The exosphere is mainly composed of hydrogen and helium.

Check out the NASA page about the Earth’s atmosphere. Here on Universe Today we have a great article about an alternative idea about the atmosphere’s origin. Astronomy Cast offers a good episode about atmospheres around the Universe.

February 7, 2010January 15, 2017 by Abby Cessna

Information About Volcanoes

An active volcano on Io, taken by the New Horizons spacecraft. Credit: NASA

Volcanoes are ruptures or fissures in the earth’s crust which leak lava. Although people think of a typical volcano as a cone-shaped one, volcanoes come in many different forms. Ancient civilizations used to associate volcanic eruptions with the actions of gods or other supernatural incidents.

Volcanoes occur most often in particular areas – where tectonic plates converge and diverge – due to the way that volcanoes form. However, they can also be found where the Earth’s crust is thinner, which makes it easier for an opening to form in the crust. The Ring of Fire in the Pacific Ocean is a good example of an area of converging tectonic plates where many volcanoes have formed.

There are a number of different types of volcanoes including fissure vents, shield volcanoes, composite volcanoes, supervolcanoes, and lava domes. Volcanoes erupt in different ways and have various types of lava. A supervolcano, a term coined to refer to a very large volcano, is defined as a volcano that ejects material more than 1,000 cubic kilometers around it. There has not been a supervolcano eruption for over 70,000 years, and the erup53tion of one would cause damage on a massive scale affecting a large region.

Volcanoes can be found both under the ocean – submarine volcanoes – and underneath icecaps – subglacial volcanoes. Submarine volcanoes can become so large that they break the surface and become islands. The Hawaiian Islands started out as submarine volcanoes. The lava that flows underneath the icecaps ends up flowing horizontally, which creates a flat mountain.

Volcanoes are not simply considered active or extinct. If a volcano has erupted recently it is active; some scientists define recently as within a period of thousands of years. If a volcano has not erupted in a while it is dormant. Dormant volcanoes are sometimes mistaken for extinct volcanoes because they can go such a long time without erupting. Normally, scientists do not consider a volcano extinct until it no longer has a lava supply.

There are also volcanoes on other planets and satellites, although most of them are not active. The only celestial bodies with active volcanoes are the Earth, Jupiter’s moon Io, Neptune’s satellite Triton, and Saturn’s moon Enceladus. Io is the most volcanically active place in the Solar System. Scientists believe that there are currently more than 400 active volcanoes on the satellite. The large amount of volcanic activity on the moon is due to the satellite’s eccentric orbit which causes tidal heating. Tidal heating is where one celestial object is heated by the effect of the gravitational pull of another celestial body.

Universe Today has articles on Ring of Fire volcanoes and 10 interesting facts about volcanoes.

You should also check out how volcanoes work and all about volcanoes.

Astronomy Cast has an episode on volcanoes.

February 5, 2010December 24, 2015 by Jean Tate

What is Schrodinger’s Cat?

Schrodinger’s cat is named after Erwin Schrödinger, a physicist from Austria who made substantial contributions to the development of quantum mechanics in the 1930s (he won a Nobel Prize for some of this work, in 1933). Apart from the poor cat (more later), his name is forever associated with quantum mechanics via the Schrödinger equation, which every physics student has to grapple with.

Schrodinger’s cat is actually a thought experiment (Gedankenexperiment) – and the cat may not have been Erwin’s, but his wife’s, or one of his lovers’ (Erwin had an unconventional lifestyle) – designed to test a really weird implication of the physics he and other physicists was developing at the time. It was motivated by a 1935 paper by Einstein, Podolsky, and Rosen; this paper is the source of the famous EPR paradox.

In the thought experiment, Schrodinger’s cat is placed inside a box containing a piece of radioactive material, and a Geiger counter wired to a flask of poison in such a way that if the Geiger counter detects a decay, then the flask is smashed, the poison gas released, and the cat dies (fun piece of trivia: an animal rights group accused physicists of cruelty to animals, based on a distorted version of this thought experiment! though maybe that’s just an urban legend). The half-life of the radioactive material is an hour, so after an hour, there is a 50% probability that the cat is dead, and an equal probability that it is alive. In quantum mechanics, these two states are superposed (a technical term), and the cat is neither dead nor alive, or half-dead and half-alive, or … which is really, really weird.

Now the theory – quantum mechanics – has been tested perhaps more thoroughly than any other theory in physics, and it seems to describe how the universe behaves with extraordinary accuracy. And the theory says that when the box is opened – to see if the cat is dead, alive, half-dead and half-alive, or anything else – the wavefunction (describing the cat, Geiger counter, etc) collapses, or decoheres, or that the states are no longer entangled (all technical terms), and we see only a dead cat or cat very much alive.

There are several ways to get your mind around what’s going on – or several interpretations (you guessed it, yet another technical term!) – with names like Copenhagen interpretation, many worlds interpretation, etc, but the key thing is that the theory is mute on the interpretations … it simply says you can calculate stuff using the equations, and what your calculations show is what you’ll see, in any experiment.

Fast forward to some time after Schrödinger – and Einstein, Podolsky, and Rosen – had died, and we find that tests of the EPR paradox were proposed, then conducted, and the universe does indeed seem to behave just like schrodinger’s cat! In fact, the results from these experimental tests are used for a kind of uncrackable cryptography, and the basis for a revolutionary kind of computer.

Keen to learn more? Try these: Schrödinger’s Rainbow is a slideshow review of the general topic (California Institute of Technology; caution, 3MB PDF file!); Schrodinger’s cat comes into view, a news story on a macroscopic demonstration; and Schrödinger’s Cat (University of Houston).

Schrodinger’s cat is indirectly referenced in several Astronomy Cast episodes, among them Quantum Mechanics, and Entanglement; check them out!

Sources: Cornell University, Wikipedia

January 25, 2010December 24, 2015 by Tammy Plotner

Online Telescopes

Have you ever wondered what it would be like to look through a telescope, but don’t have one? Are you curious if there is such a thing as an online telescope? The answer is yes. If you have a computer, you can use it to virtually look through the eyepiece of a telescope… and even aim it at the objects of your choice!

One of the most exciting concepts to come about in a long time is the SLOOH Space Camera. Here’s an opportunity to look through a variety of online telescopes located around the world and take a look at space from the comfort of your home. It’s not difficult and you don’t need complicated instructions to use it. SLOOH’s patented instant-imaging technology and user-friendly interface let’s astronomers of all ages and skill levels remotely control a real telescope!All you need is a Mac or PC computer and Internet browser to explore the deepest reaches of space. To use the Slooh online telescope you must become a member of the Club, which includes mission cards, activity books, and online gift certificates. Once enrolled, you can articipate in group missions or control the online telescopes yourself. Says PC Magazine: “Would-be astronomers can gaze at live images of the night sky, but in the comfort of their homes. Kids – even big ones will marvel when they see the Andromeda Galaxy and other distant objects slowly materialize on their computer screens.”

If you’re a bit more advanced and would like to try your hand at astrophotograpy with an online telescope, then check out iTelescope.Net. iTelescope.Net also has a variety of telescopes positioned in observatories around the world, and you can view live images as they are being created by remote astrophographers. Because taking images of the sky can involve very costly equipment and years of practice, how cool would it be just to tap into an on-line telescope and begin imaging? Now it’s as easy as taking lessons and renting the equipment – and you don’t even need clear skies or a special place to go. It’s as close as your PC!

Another type of opportunity to enjoy an online telescope in a different format is the WorldWide Telescope. While this online telescope doesn’t offer “live” views, the WorldWide Telescope (WWT) will allow your computer to act as a virtual telescope by displaying images from the foremost ground and space-based telescopes. You can even take a tour of all the most incredible places in space narrated by a real astronomer! This online telescope can provide views in multiple wavelength. Imagine seeing an x-ray view of a supernova and fading into visible light! Now you can take a look with H-alpha to view star-forming regions and examine high energy radiation coming from nearby stars in the Milky Way. Are you skies clouded out? No more. With the WorldWide Telescope you can view the Moon and planets anytime, from any location on Earth and any time in the past or future!

Would you like to use an online telescope to look at our nearest star? Then take a look at Eyes On The Skies. This simple and easy to use website offers “live” views of our Sun with an online telescope. This is the home of the internet-accessible robotic solar telescope, built by Tri-Valley Stargazers member Mike Rushford. Of course, you can only control the online solar telescope if the skies are sunny in Livermore California, USA!

January 25, 2010December 24, 2015 by Abby Cessna

Niels Bohr

[/caption]Niels Bohr was a Nobel Prize winner. He was born Niels Henrik David Bohr on October 7, 1855, in Copenhagen. His home atmosphere growing up aided his intellect and skill in physics, since he was the son of a university professor. Niels Bohr enrolled at the University of Copenhagen. At first he began to study mathematics and philosophy, but after he won a prize for examining the property of surface tension, he switched to studying physics. While there, he got both his Master’s and doctorate degrees in physics.

In 1911, in Cambridge, England, he studied with the man who had discovered the atom a decade and a half earlier. Soon after, he discovered, along with colleagues, the structure of the atom He created the Bohr atomic model in 1913, which says that electrons travel around the nucleus in a discrete orbit. He said that electrons traveled in set orbits around the nucleus. The electrons moved between these set orbits depending on whether they gained or lost energy. The Bohr model was a revision of the Rutherford model of the atom. In 1922, Niels Bohr was awarded the Nobel Prize in Physics for his work regarding the structure of atoms. He was only 37 when he won the Nobel Prize.

In 1920, Copenhagen University formed the Institute for Theoretical Physics for Bohr to head. He was in charge of the institute until his death. Following him, one of his sons who was a physicist, Aage Bohr, took over the institute. Niehls Bohr continued to study the structure of the atom’s nuclei (the Bohr atom)while he was in charge of the Institute, creating the liquid drop model of the nucleus.

He also lectured at Victoria University. In 1916, he was given the job of Professor of Theoretical Physics at Copenhagen University. He continued working in Copenhagen the rest of his life, except for when he left during the war. During World War II, Bohr fled Copenhagen and moved to Sweden and also spent time in England and America. While in the United States, he worked on the Manhattan Project. For security measures, he assumed the name Nicholas Baker while he was working on Manhattan Project. Bohr was in favor of sharing nuclear knowledge with the scientific community which was very much opposed by world leaders, such as Winston Churchill. Bohr continued to advocate sharing nuclear technology.

In addition to Bohr’s other contributions and extensive writings, he had a chemical element, Bohrium, named after him. One of Bohr’s sons, Aage Bohr, shared the Nobel Peace Prize in Physics with two others. Niels Bohr died in 1962 as a result of a stroke.

Universe Today has articles on Bohr’s atomic model and the Bohr model.

For more information, check out a biography of Niels Bohr and Niels Bohr.

Astronomy Cast has an episode on inside the atom.

Source:
Nobel Prize

January 20, 2010December 24, 2015 by Jerry Coffey

Causes Of Ozone Depletion

There are two different types of ozone depletion, both are very similar. The first one has been a slow, but steady ozone depletion of 4% per decade of the Earth’s stratosphere(ozone layer). This has been happening constantly since the 1970’s. The other is a much larger, although seasonal loss of ozone over the polar regions. This yearly occurrence is called the ozone hole. There are many causes for ozone depletion, but the most important process in both trends is catalytic destruction of ozone by atomic chlorine and bromine. Both come from the breaking down of chloroflourocarbons(freons) by photons in the atmosphere.

Chloroflourocarbons(CFC) are the ”big dog” as far as causes of ozone depletion are concerned. CFC’s are man made chemicals that are very stable in the atmosphere. They take from 20 to 120 years to break down. All the while they are destroying ozone molecules. This is what happens: CFCs do not fall back to Earth with rain, nor are they destroyed by other chemicals. Because of their relative stability, CFCs rise into the stratosphere where they are eventually broken down by ultraviolet (UV) rays from the Sun. This causes them to release free chlorine. The chlorine reacts with oxygen which leads to the chemical process of destroying ozone molecules. The net result is that two molecules of ozone are replaced by three of molecular oxygen leaving. The chlorine then reacts again with the oxygen molecules to destroy the ozone and the process repeats 100,000 times per molecule. While naturally occurring chlorine has the same effect on the ozone layer, it has a shorter life span in the atmosphere.

Of all of the causes of ozone depletion, the release of CFCs is thought to have accounted for 80% of all stratospheric ozone depletion. With great forethought, the developed world has phased out the use of CFCs in response to international agreements, like the Montreal Protocol, to protect the ozone layer. On the downside though, because CFCs remain in the atmosphere so long, the ozone layer will not fully repair itself until at least the middle of the 21st century.

The Montreal Protocol is an international agreement to address the causes of ozone depletion. While several substances were addressed, CHCs and HCFCs were the main ones that the international community agreed to phase out of production. The protocol also developed a fund to help underdeveloped countries to find other methods of production so that they could stop using CFCs and HCFCs, also.

There is a good article about the causes of ozone depletion and the Montreal Protocol at this link. Here on Universe Today we have a great article about what the ozone is and means to us. Astronomy Cast offers a good episode that describes what could happen if we lose enough of our ozone.

January 20, 2010December 24, 2015 by Jean Tate

What is the Boltzmann Constant?

There are actually two Boltzmann constants, the Boltzmann constant and the Stefan-Boltzmann constant; both play key roles in astrophysics … the first bridges the macroscopic and microscopic worlds, and provides the basis for the zero-th law of thermodynamics; the second is in the equation for blackbody radiation.

The zero-th law of thermodynamics is, in essence, what allows us to define temperature; if you could ‘look inside’ an isolated system (in equilibrium), the proportion of constituents making up the system with energy E is a function of E, and the Boltzmann constant (k or k_B). Specifically, the probability is proportional to:

e^-E/kT

where T is the temperature. In SI units, k is 1.38 x 10^-23 J/K (that’s joules per Kelvin). How Boltzmann’s constant links the macroscopic and microscopic worlds may perhaps be easiest seen like this: k is the gas constant R (remember the ideal gas law, pV = nRT) divided by Avogadro’s number.

Among the many places k appears in physics is in the Maxwell-Boltzmann distribution, which describes the distribution of speeds of molecules in a gas … and thus why the Earth’s (and Venus’) atmosphere has lost all its hydrogen (and only keeps its helium because what is lost gets replaced by helium from radioactive decay, in rocks), and why the gas giants (and stars) can keep theirs.

The Stefan-Boltzmann constant (?), ties the amount of energy radiated by a black body (per unit of area of its surface) to the blackbody temperature (this is the Stefan-Boltzmann law). ? is made up of other constants: pi, a couple of integers, the speed of light, Planck’s constant, … and the Boltzmann constant! As astronomers rely almost entirely on detection of photons (electromagnetic radiation) to observe the universe, it will surely come as no surprise to learn that astrophysics students become very familiar with the Stefan-Boltzmann law, very early in their studies! After all, absolute luminosity (energy radiated per unit of time) is one of the key things astronomers try to estimate.

Why does the Boltzmann constant pop up so often? Because the large-scale behavior of systems follows from what’s happening to the individual components of those systems, and the study of how to get from the small to the big (in classical physics) is statistical mechanics … which Boltzmann did most of the original heavy lifting in (along with Maxwell, Planck, and others); indeed, it was Planck who gave k its name, after Boltzmann’s death (and Planck who had Boltzmann’s entropy equation – with k – engraved on his tombstone).

Want to learn more? Here are some resources, at different levels: Ideal Gas Law (from Hyperphysics), Radiation Laws (from an introductory astronomy course), and University of Texas (Austin)’s Richard Fitzpatrick’s course (intended for upper level undergrad students) Thermodynamics & Statistical Mechanics.

Sources:
Hyperphysics
Wikipedia