Artist's illustration of a pulsar

Imagine an object with the mass of the Sun, crushed down to the size of Manhattan. Now set that object spinning hundreds of times a second, blasting out powerful beams of radiation like a lighthouse. That's a pulsar, one of the most exotic objects in the Universe.

VY Canis Majoris

This week we're going to talk about famous stars. But not those boring human ones you read about in People magazine. No, we're talking about those hot balls of plasma across the distant Universe. The close ones, the bright ones, the massive ones, the giant ones. Let's get to know some famous stars.

Artist illustration of a red dwarf star.

We think we live near an average star, but that's not the case at all. Compared to most stars in the Universe, the Sun is a giant! Let's look at the small end of the stellar spectrum, to stars with a fraction of the size and mass of our own Sun. There are many ways that a star can get small, and they lead dramatically different lives and deaths.

Ep. 155: Dwarf Stars

• How big (or little) is our Sun?  Sun's Mass: 1.9891 ×1030 KG
• A red dwarf is a small, cool, very faint, main sequence star whose surface temperature is under about 4,000 K. Red dwarfs are the most common type of star. Proxima Centauri is a red dwarf. (via Enchanted Learning)

• Red Dwarf Stars -- Universe Today
• Red Dwarf Stars — Wiki
• How long do stars last? — Universe Today
• Paper:  Habitability of Planets Around Red Dwarf Stars – University of Texas
• Gliese 581 — Wiki
• Hydrogen Burning — Cornell
• Brown Dwarf Stars – Cool Cosmos
• Research on Brown Dwarfs — UC Berkeley
• Red Dwarf Stars – Universe Today
• Red Dwarfs — Wiki
• Electron Degeneracy Pressure — Wolfram
• White Dwarf -- GSU
• White Dwarf – Goddard SFC
• Background radiation of the Universe (CMB) — UBC
• Black dwarf stars – Universe Today
• Black dwarfs – Wiki
• How are black dwarf stars and neutron stars similar? Goddard SFC
• Blue stragglers in globular clusters — SolStation
• Looking for Planets Around White Dwarf Stars -- Professor Astronomy
• Ep. 86 End of Everything Pt. 1
• Ep. 87 End of Everything Pt. 2

Artist's illustration of a cataclysmic variable

Did you know that our Solar System is a rarity with its single star. Astronomers believe that most star systems out there actually contain 2 or more stars – imagine seeing a sky with 4 suns. These binary and multiple star systems are a great target for new astronomers, and the dynamics of multiple stars keep astrophysicists busy too. Let's take a look at what it would be like to live on Tatooine.

Ep. 152: Binary Stars

• Tatooine – Wookipedia
• Binary Stars — Universe Today
• Cygnus binary system
• Binary stars that merge — COSMOS
• Algol, the most famous eclipsing binary system — UTK
• Visual Binary Stars – UTK
• Mizar in the Big Dipper — Astropix
• Astrometry
• Spectroscopic Binary Stars — UTK
• Blue Stragglers — Cornell U.
• Accretion Disks — NASA
• White Dwarfs
• Electron Degenerate gas — University of Texas
• Pauli Exclusion Principle
• Alpha Centauri System

Betelgeuse. Image credit: Hubble

This week we find out the distance between Betelgeuse and Bellatrex, how astronomers measure distance between objects, the possibility that an object could mess up the orbit of Earth, and the reason for different sizes of stars. If you've got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.

Distance in Space, Changing Earth's Orbit, and Different Sized Stars

Distance between Betelgeuse and Bellatrex

• Betelgeuse is 640 lightyears from Earth (see bottom of linked article to see updated distance)
• Bellatrex is 240 lightyears from Earth
• Parallax: brightness and distance – UIUC
• Measuring angular distances — Vanderbilt U
• How Can We Measure Distances to Stars? — Cornell U
• Hipparcos Space Astrometry Mission
• Recent article on Belegeuse's bow shock — Universe Today
• AC Episode 22:  Variable Stars

Could an object coming through our solar system change Earth's orbit?

• Discussion of changing Earth's orbit – Physics Forums
• Moving the Earth: A Planetary Survival Guide – New Scientist
• Planet X is Not Nibiru – Universe Today
• No Planet X – Universe Today

Why are there different sizes of stars?

• Dr. Marc Rayman of JPL answers the question on The Space Place (transcript)
• Space Place podcast of Rayman's answer

What are Pamela and Fraser most excited about in outstanding questions in astronomy?

• Pamela:  Dark Energy, Dark Matter
• Fraser:  Higgs Boson

Is is possible there isn't dark energy?

• What is dark energy? – NASA
• Chandra observations confirm dark energy – Universe Today
• The Expanding Universe — SDSS

What are the surface of gas planets like?

• If Saturn and Jupiter are gas giants, could you fly through them? – NASA's Space Place
• Gas Giants

How did Astronomy Cast get started?

• Slacker Astronomy
• Slacker Astronomy Council of Doom
• Phil Plait
• About Us link (or see above)