Ep. 152: Binary Stars

Astronomy, Stars | 10 comments

Artist's illustration of a cataclysmic variable

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
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    1. Steve McGee

      Actually, if Jupiter were to be 4 or 5 time larger, it would be considered a “brown dwarf” and therefore qualify our solar system as a binary system.
      If your guest is so bored with binary systems, maybe you should have chosen someone who is excited and knows a little about and studies binaries.
      Your guest is more into variables.
      There are a great many professional and amateur astronomers doing new discoveries in the binary field. The circular, The Journal of Double Star Observations, is quite up-to-date in the field. There are 101 authors contributing to this journal.
      The binary-stars-uncensored Yahoo Group is a vibrant group of amateurs contributing to the field.
      The joy of observing, and measuring binaries are a great on-going pastime for amateurs with all sizes of scopes. This podcast doesn’t inspire a budding astronomer to study binaries. It baffles the curious with wordy hypotheses requiring elaborate and sophisticated equipment to study variables.

    2. Ben

      Pamela isn’t a guest Steve, she’s the co-host!
      Like any other astronomer, Pamela has her own research interests and despite this, she manages to be entertaining and knowledgeable about the huge range of topics covered in Astronomy Cast’s back-catalogue. Many of which she probably doesn’t really engage with in her day-to-day work. To me this shows how much effort she puts in to researching the topics in her own time and for free.
      I really enjoyed this episode! I want to study X-ray binaries when I reach post-grad level and would have found this useful when I first became interested in the subject as will any budding stellar physicist now.
      Fraser and Pamela: Thanks for all your efforts and keep those catch-up shows coming!

    3. A James

      This episode is just so dismal and SO very confusing.
      I mean…
      Cygnus B? Does Pamela mean Beta Cygni?
      Wouldn’t the best initial example have been Alpha Centauri?
      Eclipsing variable, spectroscopic binaries, visual binaries are different classes of binaries – this should have been said in the very beginning.
      IMO, binary stars are not boring at all.
      Sample pages on double / binary stars, see basic summaries;
      This whole webcast is disappointing and far too flippant!

    4. Matt

      Astronomy Cast is great.
      I agree with Ben above. Pamela is the greatest. They provide a service weekly for FREE to us! Geeze! Some people…. Okay, back to listening to show…
      **headphones on**
      You all are doing great

    5. dave fernandes

      I agree with Ben as well. If you understood how hard Dr. Gay works in a week, you’d be blown away. She’s an amazing individual that works to educate the community. Check out the other episodes. She’s amazing and has inspired my daughter to think about astronomy.

    6. A James

      Actually, what is missing here in this podcast is the real importance of binary stars. Binary stars are the only means of measuring mass directly, which is gain by learning the system’s orbital elements via many measures of the changing positions over time. Of course, the other advantage is stellar parameters (density, physical sizes, etc. etc.) can be derived directly, thus improving stellar evolutionary constraints.
      Sure it might be “like watching paint dry”, but the uniqueness is observations take since in 1780s have been accumulated enough to prove gravitational relationships or change alignment by unrelated stars. Just because the astronomy discipline doesn’t give an instant result really doesn’t mean it is boring.
      Another point too. Has no-one ever heard of the important “Mass-Luminosity Relationship” – whose given slope fundament to our understanding of all the distant stars? Without it stellar evolution theory has no means of directly measuring the mass of stars throughout the galaxy.
      For studies into finding and observing visual binaries, we can summarise their importance by;
      1) Pair discovery
      2) Extensive observation of systems that showed binary motion.
      3) Determination of orbital parameters, and therefore the derivation of mass.
      4) Spectroscopic or photometric observations
      5) Photometric observations of eclipsing binaries
      6) The formulation of the mass-luminosity relationship
      7) Introduction of modern observation techniques like speckle interferometry
      As for Matt and dave ferrandes comments… It doesn’t matter if the podcast is free, given by an expert, or brilliant in presentation. The simple fact is that what is said here is very much misrepresenting the importance of binary stars in astronomy and astrophysics. It fails because it wrongly leaves the impression that the line of study is merely incidental when it is the core of stellar evolution theory and its provides the means of DIRECTLY comparing all stars.
      Really, Robert G. Aitken -author of the definitive tome “The Binary Stars”, would be now turning in his grave.
      Note: If you wish to be truly inspired, then read the following ADS on-line papers;
      Robert Aitken “On Observing Double Stars” ;
      or the inspiring words in;
      Robert Aitken “Early Work on Double Stars at the Lick Observatory”
      I’ve been interested in double and binary stars for decades, and I have never found it “boring”.
      Interview me Fraser, and I’ll turn all these doubters into raving fanatics!!

    7. Conway

      Well Steve Jupiter is not 4 or 5 times bigger and so remains a planet in our Solar System.. I think Dr Pamela is more than qualified to be speaking on this topic.. Keep up the good work guys….

    8. Greg Slick MD

      I would like to express my thoughts about what a wonderful , exciting and educational site this is. It is obvious to me the HUGE amount of work put into producing these podcast. The material is accurate and presented so well that even a novice like me can grasp and understand. Good teaching looks easy but it is NOT! Thanks for your efforts and PLEASE keep up the good work!

    9. Ahmed

      Dr. Gay is a great person. I agree with all of you guys. 🙂


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