Podcast Summary
Exploring the Wonders of the Universe Through Astronomy and Fashion: Astronomy expert Emily Rice turned her passion for the cosmos into a successful business, Star Torialist, which combines cosmic fashion with scientific knowledge.
The universe is full of wonders beyond our immediate understanding, from the vast expanses of galaxies to the intricacies of newborn stars and exoplanets. My friend and colleague, Emily Rice, is a leading expert in this field and has even turned her passion for astronomy into a successful business, Star Torialist, which brings cosmic fashion to the public. Started as a blog to share the stories behind astronomical-themed clothing and accessories, Star Torialist has grown into an online shop where they create their own unique items. Emily's journey began as a way to share her love of astronomy with others, but it has continued to thrive as people's interest in the cosmos remains strong. And while the mysteries of the universe, such as dark energy, may still be largely unknown, the excitement and curiosity they inspire never fade. Emily's work in studying newborn stars, exoplanets, and brown dwarfs pushes the boundaries of our knowledge and adds to the rich tapestry of discoveries in the field of astronomy.
The Origin of the Term 'Brown Dwarf': The term 'brown dwarf' was coined in the 1970s for celestial objects that emit radiation and have a definite structure, replacing the term 'black dwarf' which was used for theoretical objects lacking enough mass to fuse hydrogen and helium.
The term "brown dwarf" was coined in the 1970s for celestial objects that were once called black dwarfs. The change in name came about due to the discovery that these objects, which form between stars and planets, are not fully unexplained by normal physics as previously thought. Jill Tarter, a renowned astronomer and a friend of StarTalk, first proposed the term brown dwarfs in her thesis in 1975. The term "black dwarf" was used initially for theoretical objects that lacked enough mass to fuse hydrogen and helium, resulting in a steady source of power. However, as research progressed, it was discovered that these objects do emit some radiation and have a definite structure. The term "black dwarf" was then replaced with "brown dwarf" to better reflect their true nature. This shift in understanding took place around the same time when black holes were gaining significant attention in the scientific community. It's fascinating to note that the term "brown dwarf" was coined over 45 years ago, but they were not discovered until the 1990s. This conversation serves as a reminder of the incredible advancements in science and technology that have taken place in just a few decades.
Rapid Dissemination of Scientific Discoveries: Scientific discoveries spread quickly today, contrasting past methods like teletype, and the naming of spectral types for stars continues to evolve, causing confusion but also job security.
We are currently living in an era where groundbreaking scientific discoveries are being shared with the public at an unprecedented speed. This was exemplified by the quick dissemination of the new polarized image of the black hole at the center of the Milky Way galaxy. This rapid sharing of information was reminiscent of the past when significant discoveries had to be communicated through teletype, but now, it's as simple as showing an image in a classroom or putting it on a t-shirt. The speaker, a research associate and associate professor of astrophysics, shared his experiences of bringing students to the American Museum of Natural History and being a founding member of BDNYC, which has its own unique story behind the letters in its name. The naming of spectral types for stars, including the addition of brown dwarves and their subsequent subcategories, has caused confusion but also job security for scientists as they continue to discover and categorize new phenomena in the universe.
Similarities between Brown Dwarfs and Exoplanets: Recent discoveries reveal that brown dwarfs and large exoplanets share similarities in size, temperature, and evolution, challenging the traditional distinction between the two.
Brown dwarfs and exoplanets share more similarities than differences, particularly in terms of their structure and evolution. This discovery came about as a result of the discovery of white dwarfs and the realization that the distinction between brown dwarfs and planets is not as clear-cut as once thought. The mass threshold that separates brown dwarfs from stars was once set at 13 Jupiter masses, but it has since been recognized that this demarcation doesn't make a significant difference in the long term. Brown dwarfs, which are unable to sustain nuclear fusion, are similar in size and temperature to large exoplanets. The BD NYC community, founded over a decade ago by women in astronomy, has been at the forefront of this research, publishing papers and leading campaigns to expand our understanding of these celestial bodies. The discovery of the similarities between brown dwarfs and exoplanets has opened up new avenues for research and exploration in the field of astronomy.
Exploring the similarities between hot Jupiters and brown dwarfs: The discovery of massive exoplanets, or hot Jupiters, has led to increased collaboration between different areas of astronomy, particularly in understanding their similarities and differences with brown dwarfs, and the formation and heating mechanisms of these celestial bodies.
The discovery of massive exoplanets, such as those five to ten times the mass of Jupiter, has led to increased collaboration between different areas of astronomy, including the study of brown dwarfs and planetary science. These exoplanets, known as hot Jupiters, are similar to brown dwarfs in terms of mass and temperature, but differ in the source of their heat. While brown dwarfs radiate from the inside, hot Jupiters are heated from the outside by their host stars. Additionally, the formation and creation of low-mass stars, including those with low densities, is still not fully understood. The ongoing discovery and study of these celestial bodies continue to reveal new insights and collaborations in the field of astronomy.
Uncertainty in Astronomy: Age-Mass Degeneracy of Dwarf Stars: Scientific discovery involves uncertainty, as astronomers face challenges in distinguishing between young, low-mass brown dwarfs and old, high-mass ones due to age-mass degeneracy.
The universe may not make sense to us, and uncertainty is a natural part of scientific exploration. Scientists confidently admit what they don't know, and this uncertainty drives the scientific process. Unlike science, religion often claims to have answers, even when they contradict each other. In astronomy, the discovery of dwarf stars presents a challenge. Stars and brown dwarfs have similar temperatures, luminosities, and masses for long periods, making it difficult to determine their ages and masses. This ambiguity is known as the age-mass degeneracy. Astronomers cannot definitively tell if they are observing a young, low-mass brown dwarf or an old, high-mass brown dwarf based on their current data. This ambiguity highlights the complexity and uncertainty inherent in scientific discovery.
Ambiguity in Determining Mass and Age of High-Mass Brown Dwarfs: Degeneracy pressure and age-mass ambiguity complicate the study of high-mass brown dwarfs, making it difficult to precisely determine their mass and age due to quantum states filling up and ambiguous age-mass relationships.
The term "degeneracy" in astrophysics is used in two distinct ways, leading to ambiguity and complexity in understanding astronomical phenomena. Degeneracy pressure, a quantum mechanical concept, arises when electrons in atoms get so close together that they fill up quantum states, providing pressure against the mass. Age-mass degeneracy, on the other hand, refers to the ambiguity in determining the age and mass of astronomical objects without constraining one with the other. These concepts make it challenging to precisely determine the mass and age of high-mass brown dwarfs, which can be difficult to distinguish from stars. Additionally, magnetic fields in brown dwarfs are not well understood, adding another layer of complexity to studying these objects.
Understanding Magnetic Fields in Stars and Brown Dwarfs: Magnetic fields in stars, including brown dwarfs, are crucial for various phenomena but their origin and nature in brown dwarfs are less clear. Ongoing research explores the interplay of convection, radiation, and dynamo effects to uncover new insights.
The formation and behavior of magnetic fields in stars, including brown dwarfs, is still an area of active research and understanding. Stars, like our Sun, exhibit magnetic fields that are crucial for various phenomena such as solar wind and sunspot activity. However, in brown dwarfs, the origin and nature of magnetic fields are less clear due to their unique properties. The magnetic fields in these objects are believed to result from the interplay of convection, radiation, and dynamo effects. While we don't have definitive answers yet, ongoing research continues to uncover new insights and discoveries. Atticus, a 9-year-old from Soddy Daisy, Tennessee, asked an intriguing question about what would happen if two brown dwarfs collided. The answer remains uncertain, but it underscores the importance of continued exploration and investigation in this fascinating field of astrophysics.
Star Collisions and Stellar Evolution: Stellar mergers can ignite hydrogen fusion, resulting in a reorganized star with a prolonged life. This phenomenon is more common in higher mass stars and creates more energy. Blue stragglers, hotter and bluer stars in a cluster, may result from stellar mergers, but evidence for brown dwarf mergers is rare.
When two stars, including brown dwarfs, collide, it's possible for hydrogen fusion to ignite, resulting in a reorganized star with a prolonged life expectancy. This phenomenon, known as stellar mergers, creates more energy and is more commonly observed in higher mass stars due to the greater energy loss from their orbits. Blue stragglers, which are hotter and bluer than other stars in a cluster, are believed to be the result of stellar mergers. While it's theoretically possible for a brown dwarf to be ignited through mergers, it's not a common occurrence and evidence for it is hard to find. Atticus, a 9-year-old with a deep interest in the universe, asked about this topic, leading to a fascinating discussion about the possibilities of star collisions and their implications on stellar evolution.
Older low mass stars hold secrets of the universe's past: Older low mass stars, like brown dwarfs, have longer lifespans and contain less heavy elements, making them valuable for studying the early universe through 'galactic archaeology'.
The lifespan of low mass stars, such as brown dwarfs, is significantly longer than that of other stars like our sun. This makes them valuable for "galactic archaeology," as some of the oldest low mass stars could have been present since the early stages of the universe. The difference between older and newer low mass stars can be determined by analyzing their spectra and the amount of heavy elements they contain. Direct imaging of exoplanets, while currently limited to a handful of pixels and planets, is an area of ongoing research and improvement in space telescope technology. The ability to capture detailed images of exoplanets, revealing their unique features, is an exciting prospect for the future of astronomy.
Exploring Exoplanets Around Small Stars: Small stars offer better targets for finding Earth-sized planets due to their smaller size and lower luminosity, making it easier to detect smaller planets closer to the star. The TRAPPIST-1 system, with seven Earth-sized planets, is a notable discovery in this area.
Small stars, particularly low mass stars and brown dwarfs, could be better targets for finding Earth-sized planets due to their smaller size and lower luminosity. This makes it easier to detect smaller planets orbiting closer to the star using indirect methods. The TRAPPIST-1 system, which hosts seven Earth-sized planets, is a prime example of this discovery. Although there are still unknowns regarding the atmospheric conditions of these planets, the potential for finding planets with liquid water in the habitable zone around small stars is exciting. The Hubble Space Telescope and ground-based telescopes have made significant discoveries in this area, including the HR 8799 system with its large planets orbiting a brighter, bigger star. Overall, the exploration of exoplanets around small stars is an intriguing and promising area of research.
Exploring the universe broadens our horizons: The universe's exploration expands our knowledge and perspective, potentially leading to significant discoveries and advancements, despite Earthly problems.
The exploration and understanding of the universe, despite the existence of Earthly problems, expands our perspective and knowledge, potentially leading to significant discoveries and advancements. This was emphasized in the discussion, where Neil deGrasse Tyson reflected on the importance of astrophysics and the discovery of new fields, such as the study of stellar evolution, which could help us find life beyond Earth. Although it may not directly solve Earthly issues, the value of the universe and its exploration is immeasurable, as it broadens our horizons and deepens our connection to the cosmos.