Astronomy Minute: Recent Episodes
Ata Sarajedini
Learn the basics of astronomy in one-to-two minute packets of concise information about specific topics. You are a busy person with a short attention span, and you want to learn about astronomical topics in a short amount of time. Your host Professor Ata is a PhD research astronomer and astrophysicist and a noted authority on stellar and galactic astronomy. I welcome your feedback at ata.sarajedini@gmail.com. See the web site astronomyminute.org for more. The podcast logo is courtesy of Zachary Greathouse and shows a globular cluster photo taken by the author with the Hubble Space Telescope.
A brief description of what constitutes and astronomical observatory with a few examples in the real world that you have probably heard of.
A brief description of the philosophical concept known as Occam's Razor, which asserts that “the simplest explanation of a particular natural phenomenon is usually the correct one.”
A brief description of why the Webb Telescope is optimized to observe infrared light. Hint: it has to do with the four main science areas that it will be studying: “Other Worlds,” “Star Lifecycle,” “Galaxies Over Time,” and “Early Universe.”
A brief description of the four main science goals of the James Webb Space Telescope - “Other Worlds,” “Star Lifecycle,” “Galaxies Over Time,” and “Early Universe.”
A brief description of the James Webb Space Telescope and how it's different than the Hubble Space Telescope.
A brief description of the two primary reasons why we send telescopes into space to observe and study celestial objects.
A brief description of what will happen if the universe stops expanding and collapses back on itself - this is known as the Big Crunch.
A brief description of the basic properties of astronomical objects such as mass, radius, distance, luminosity, and temperature.
A brief description of the Local Group of galaxies which contains the Milky Way, the Andromeda galaxy, and dozens of dwarf galaxies all gravitationally bound to each other.
A brief description of the structure of atoms - how they are mostly empty space - and why the everyday objects you use don't collapse and fall in on themselves.
A brief description of nuclear fusion, which is the process by which stars produce light so that they can shine.
A brief description of the observational evidence we have supporting our assertion that the Milky Way galaxy is spiral in shape.
A brief description of the 21 centimeter radiation (light) that the Hydrogen atom emits and the mechanism behind this emission.
A brief description of what astronomers mean when they say that "all pulsars are neutron stars but not all neutron stars are pulsars."
A brief description of neutron stars, which are essentially the end state of massive stars some of which become pulsars.
A brief description of a white dwarf star, which is the end-state of a star that is less than 8 times the mass of Sun.
A brief description of how we use the HR Diagram and the main sequence to measure the ages of stars in groups and clusters.
A brief description of the true nature of black holes as highly localized sources of gravity and not cosmic vacuum cleaners.
A brief description of what we think was here before the Big Bang. Short answer is that we don't know since "Science" is not equipped to answer questions where no data or information is available.
A brief description of my personal point of view regarding the possibility that UFOs harbor extraterrestrial beings visiting Earth.
A brief description of the Hubble Law, now more formally known as the Hubble-Lemaitre Law.
A brief description of starburst galaxies and why they are in star formation overdrive.
A brief description of whether the findings of science are _absolutely_ true. It could also have been entitled “Are Scientific Results Absolute?” and “Is the Scientific Method Absolute?”
A brief description of what is meant by dimensional analysis. In short, the final units in a calculation must be correct for the calculation to be correct.
A brief description of Einstein’s Theories of Special Relativity and General Relativity?
A brief description of how we mathematically relate cause and effect in science. A short description of the equation of a straight line, y=m*x + b is also included.
A brief description of the different kinds of lunar and solar eclipses and how they happen.
A brief description of what makes Earth unique from the other terrestrial planets - active plate tectonics, liquid water, a significant atmosphere, and the rich diversity of life.
Some advice for anyone wanting to pursue professional astronomy/astrophysics as a career choice.
A brief description of how atoms absorb and emit particles of light known as photons based on the Bohr Model of the atom. This leads directly to the creation of absorption and emission lines in the spectra of stars.
A brief description of some deep sky objects whose names you may have heard of in popular culture.
A brief description of what is meant by retrograde motion of the planets in the Solar System.
A brief description of the professional organizations that support the work of astronomers in North America and worldwide.
A brief description of the process used to allocate telescope time to professional astronomers interested in addressing scientific questions.
A brief description of how astronomers disseminate their research results to other scientists.
A brief description of how we quantify the amount of metals in a star, i.e. how much of the star is composed of elements heavier than Helium, using a logarithmic quantity designated as Fe over H, or simply [Fe/H].
A brief description of light pollution and why astronomers are so concerned about its effects on the brightness of the night sky.
A brief treatment of the limitations of science as pertains to seeking the truth in other areas outside of the natural world.
A brief description of the notable celestial objects located in the constellation of Virgo.
A brief description of the notable celestial objects located in the constellation of Ursa Major.
A brief description of the notable celestial objects located in the constellation of Tucana.
A brief description of the notable celestial objects located in the constellation of Triangulum.
A brief description of the notable celestial objects located in the constellation of Scorpius.
A brief description of the notable celestial objects located in the constellation of Ophiuchus.
A brief description of the notable celestial objects located in the constellation of Monoceros.
A brief description of the notable celestial objects located in the constellation of Leo.
A brief description of the many facets of astronomy and what attracts us to study and gaze upon the night sky.
A not-so-brief description of the relation between Local Sidereal Time and Local Time. For the purposes of this podcast, Local Time, Local Apparent Time, and Standard Time are largely interchangeable.
A brief description of the notable celestial objects located in the constellation of Dorado.
A brief description of what is meant by Local Sidereal Time. In a nutshell, Local Sidereal Time or LST is the Right Ascension of the Meridian.
A brief description of the way astronomers identify the locations of stars and other celestial objects relative to the plane of the Milky Way galaxy known as the Galactic Coordinate System.
A brief description of one of the ways astronomers identify the locations of stars and other celestial objects in the sky known as the Altazimuth Coordinate System..
A brief description of altitude and azimuth and how they are used to located objects in the sky.
A brief description of one of the ways astronomers identify the locations of stars and other celestial objects in the sky known as the Equatorial Coordinate System.
A brief description of what quantum mechanics is and how it relates to other areas of physics.
A simplified description of one method we can use to calculate the age of the universe using the Hubble Constant.
A brief description of the notable celestial objects located in the constellation of Crux.
A brief description of the notable celestial objects located in the constellation of Coma Berenices.
A brief description of the notable celestial objects located in the constellation of Cetus.
A brief description of the notable celestial objects located in the constellation of Cassiopeia.
A brief description of the notable celestial objects located in the constellation of Canis Major.
A brief description of the notable celestial objects located in the constellation of Cancer.
A brief description of the notable celestial objects located in the constellation of Canes Venatici.
A brief description of the notable celestial objects located in the constellation of Centaurus.
A brief description of the notable celestial objects located in the constellation of Taurus.
A brief description of the notable celestial objects located in the constellation of Sagittarius.
A brief description of the notable celestial objects located in the constellation of Orion.
A brief description of the notable celestial objects located in the constellation of Lyra.
A brief description of the notable celestial objects located in the constellation of Hercules.
A brief description of the notable celestial objects located in the constellation of Cygnus, the Swan.
A brief description of the notable celestial objects located in the constellation of Andromeda.
A brief description of what is meant when astronomers refer to something as a deep sky object?
A brief description of how we define an asterism in the sky as distinct from a constellation.
A brief description of why we study the nature of the Universe. We are mainly interested in gaining knowledge about the universe for the sake of the knowledge itself.
A brief description of how the finite speed of light can be used to our advantage - allowing us to look back in time to see the history of the Universe.
A brief description of how old the universe is as compared with the ages of the Sun, the Earth, and how long Homo Sapiens have lived on the Earth.
A brief description of a light year - a unit of distance based on how far light travels in one Earth year.
A brief description of electromagnetic radiation - that is to say light - and how its wavelength, frequency, and energy are related.
A brief description of the term Hubble Flow in astronomy. The universe is expanding on the largest scales, and this large-scale expansion of the Universe is known as the Hubble Flow.
A brief description of Blackbody or Planck curves. In short, these curves tell us the brightness of stars of a certain temperature.
A brief explanation of the zodiac and how it relates to the other constellations in the sky.
A brief order-of-magnitude description of the probability of life elsewhere in the universe beyond earth.
A brief description of two independent methods that give an age of 4.5 billion years old for the Solar System.
A brief description of how we think the Milky Way galaxy formed. Basically, it's a process whereby hundreds to thousands of low-mass dwarf galaxies collided and coalesced to form our our galaxy.
A brief description of taxonomy in science and how it is used to classify objects that are similar to each other.
A brief description of two dwarf galaxies known as the Large and Small Magellanic Clouds that are in orbit around own Milky Way galaxy .
A brief description of Isaac Newton's contributions to science and mathematics. More information is available in the podcasts entitled “What are Newton’s Laws of Motion?” and “What is Newton’s Law of Universal Gravitation?”
A brief description of how the motion of the Moon around the Earth, the Earth around the Sun, the Sun around the center of our galaxy, and the motion of the galaxy itself are like clockwork.
A brief description of the basic contributions Nicolaus Copernicus made to the science of astronomy.
A brief description of the techniques we use to detect the presence of planets orbiting around other stars besides the Sun. These techniques are known as Transit Photometry and Doppler Spectroscopy.
A brief description of the definition of a Bell Curve - also known as a Normal Distribution and a Gaussian Distribution; it is very important in the fields of statistics and probability.
A brief description of Right Ascension and Declination and how they are used to locate objects in the sky.
A brief description of what causes the phases of the Earth's Moon. An animation/movie linked off of the web page helps to explain the podcast.
A brief description of what doesn't cause the seasons and what we actually believe does cause them. There is also a graphic linked off the web page that helps explain this episode.
A brief description of what we mean when we say that two numbers differ by an order to magnitude. This includes a summary of what a Logarithmic is.
A brief description of why we expect the Sun to have been formed in a multiple star system and how we are searching for the other stars formed with it.
A brief description of the difference between random errors and systematic errors in science.
A brief description of the magnitude system in astronomy including the difference between apparent magnitude and absolute magnitude.
A brief description of the Kelvin temperature scale as compared with Fahrenheit and Celsius.
A brief description of what comets are and how they are responsible for meteor showers on the Earth.
A brief description of the Cosmic Microwave Background (CMB) also known as the Primordial Background Radiation.
A brief description of the main components of the interstellar medium, which is the stuff in space between the stars.
A brief description of what tidal forces refer to and why they are important in astronomy.
A brief description of the different types of telescopes and the most important characteristic to consider when comparing them.
A brief explanation of why the sky is blue within the context of the Scientific Method as described in the episode "What is Science?"
A brief explanation of interstellar reddening and extinction and why understanding their effects is important in astronomy.
A very brief description of the Giant Impact Hypothesis that describes how the moon formed.
A brief description of angular momentum and how it is conserved in rotating systems that we encounter in astronomy.
A brief description of the Hertzsprung Russell (HR) Diagram and its primary feature known as the main sequence.
A brief description of the Doppler Effect and how it can be used to measure the motion of celestial objects toward (via blueshift) and away (via redshift) from us.
A brief description of the inverse square law of light and how we use it to determine the distances of celestial objects.
A brief description of how science does not prove things but rather provides evidence in favor of or against a particular theory.
A description of the main piece of evidence supporting the hypothesis that there is a black hole at the center of our galaxy.
A basic description of an active galaxy and how it produces the energy that we observe from it.
A brief description of the Nebular Hypothesis which is believed to describe how the Solar System formed.
A description of Precession of the Equinoxes which determines what the north star will be.
A description of one of the main reasons why Pluto is no longer classified as a planet.
A brief description of the two very broad categories into which variable stars are classified.
A description of what helioseismology is and how we can use it to determine the various properties of the Sun.
A brief explanation of what professional astronomers actually do in their role of applying the scientific method to better understanding the Universe.
A brief description of the ways in which we analyze light to help us better understand the Universe.
A basic description of what cosmology is and the assumption we need to make in order to apply it to the universe.
A basic explanation of our theory for how light, a.k.a. electromagnetic radiation, behaves.
A very brief description of how we measure distances of celestial objects. This is truly a 30,000 foot view of a very complicated subject.
A brief description of the celestial sphere and how astronomers precisely locate objects in the sky.
A description of how stars live their lives and evolve with a little about how they end their lives.
A description of how astronomers use everyday language to refer to the objects they are studying.