Ep. 642: Is the Sun… Normal?
Description
We’ve always assumed that we lived in a perfectly normal system with a normal star and normal planets. It’s all… normal. But with our modern understanding of billions of stars, just how normal is our Sun, anyway?
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Show Notes
Patreon: Universe Today
Patreon: CosmoQuest
Sun (NASA)
The Fermi Paradox (SETI Institute)
What’s a neutrino? (Fermilab)
White Dwarf (Swinburne University)
Planetary Nebulae (Swinburne University)
Red Dwarf (Swinburne University)
Brown Dwarf (Swinburne University)
WISE (Caltech)
JWST (NASA)
Rubin Observatory’s Legacy Survey of Space and Time (LSST) (SLAC)
Roman Space Telescope (NASA)
Main Sequence Stars (CSIRO)
Hertzsprung-Russell Diagram (Swinburne University)
What are red giants? (EarthSky)
Subramanyan Chandrasekhar (The Nobel Prize)
Spectroscopy (Swinburne University)
Metallicities and Stellar Populations (Case Western Reserve University)
Abundance Ratio (Swinburne University)
Gaia (ESA)
Uncovering the birth of the Milky Way through accurate stellar ages with Gaia (Nature Astronomy)
TESS – Transiting Exoplanet Survey Satellite (NASA)
Transcript
Transcriptions provided by GMR Transcription Services
Fraser: Astronomy Cast, episode 642: Is the sun normal? Welcome to Astronomy Cast, your weekly facts-based journey through the cosmos, where we help you understand not only what we know, but how we know what we know. I’m Professor Cain, publisher of Universe Today. With me, as always, is Dr. Pamela Gay, a senior scientist for the Planetary Science Institute, and the director of CosmoQuest. Hey, Pamela, how are you doing?
Dr. Gay: I am doing well. It is exciting times around here. My hair and my camera have both decided it is time to celebrate the 80s and glitch in proper Max Headroom and frizzy, curly style –and I think this works. So, we’re gonna go with it.
Fraser: You have hot humidity working on both of them at the same time.
Dr. Gay: It’s true.
Fraser: Just recking cameras in here.
Dr. Gay: Yes.
Fraser: So, before we get into this week’s episode, I just wanna do a rare, shameless self-promotion for something that we’re doing on Universe Today. So, as you probably know – well, maybe people don’t know this, but –
Dr. Gay: No, tell them.
Fraser: – when you support the Patreon for Astronomy Cast, you’re not actually supporting me or Pamela. You are supporting the team that maintains Astronomy Cast week after week after week. Our editors, our produces, everybody, the server hosting fees, all of that. But actually, we don’t take a salary from this. It’s a nonprofit. But we both have Patreons.
So, for the Universe Today Patreon, which support the work I do with all of the –with all of the –giant team of writers that we have on Universe Today, all of that, the video editors, auto-editing, and so on, we’ve been hovering under the sort of 800 and 900-mark, and people have been asking me to do some kind of book club. And so, we decided we’ll do that if we can reach 1,000 patrons for Universe Today.
So, if you go to patreon.com/universetoday, join as a patron, help us reach that 1,000-mark. And it’s a bit of a race. We’ve mentioned this on our channel. We’re gonna try and hit 1,000 patrons before either Space Launch System or the SpaceX Starship launch. Can you help us? Just show that we’re the real rocket ship here. Pamela?
Dr. Gay: That is amazing. And I – yeah. We, over at CosmoQuest, we are in the process of doing our final push, just like Astronomy Cast, through to mid-July, and that hiatus, and we’re in the process, right now, of planning out this year’s CosmoQuest-a-Con. Normally, we do CosmoQuest-a-Con in July, but no lies, I have no air conditioning in my house, and I like my team. So, we are not going to do CosmoQuest-a-Con in July because I like my team.
So, instead, we’re doing in October, but our goal is to have everything planned out by July and to sell enough tickets that we don’t have to do a Hangout-a-Thon this year. So, we’re selling tickets. Links are over at CosmoQuest.O-R-G for our October event. It’s themed, Rockets and Robots, and we have an amazing slate of people. So, go get your tickets today.
Fraser: Awesome. All right. So, we’ve always assumed that we lived in a perfectly normal start system with a normal star, normal planets. It’s all normal. But with our modern understanding of billions of stars, just how normal is our sun anyway? All right. Are we normal?
Dr. Gay: No.
Fraser: What?
Dr. Gay: But would we want to be?
Fraser: Yeah –I guess it doesn’t –Yes. You know what? I’ve decided that, yes, we would want to be normal because then that would mean that all of the other yellow dwarf stars that we see out there probably have planets. All the planets probably have the same distribution as we have in our solar system. Probably a rocky world orbiting in the habitable zone, and that means that there’s gonna life everywhere. Yes, please. Yes. We wanna be normal. This should be the template for what the universe should be like. Everywhere you go, it’s just solar systems everywhere.
Dr. Gay: All right.
Fraser: But that’s not real.
Dr. Gay: No. No. And I suspect the Fermi Paradox wouldn’t be a thing if your version of normal was a thing.
Fraser: That’s true. True. True. All right. So, I guess, do you wanna start with –what’s some of the interesting characteristics about our sun and then start to compare that and how we know? So, I guess –let’s define our sun, for a second.
Dr. Gay: All right. So, our sun is –a 10 to the 33-gram star. I don’t know why we measure these things in grams. We do.
Fraser: Well, you can do 10 to the 33 kilograms, if you like.
Dr. Gay: It’s true. It’s true.
Fraser: Yeah.
Dr. Gay: It –glows a yellowy-white color. If we were seeing it without our atmosphere, our eyeballs would see it as much more white than it sees it as yellow, simply because our atmosphere is scattering out some of that blue light. So, our sky lies to us. Temperature-wise, it’s more of a yellowy hue, so those old incandescent bulbs that we should no longer have in our house – houses, those were more solar temperature than the blue LEDs that we’re dealing with. Our sun is about 1.3 percent metals which is anything other than hydrogen and helium, and it’s just out there combining atoms to end up with light shining our way and a variety of neutrinos coming out of those reactions.
It’s only in comparison that our sun get interesting. Really. It’s kinda boring to just look at it by itself.
Fraser: But boring says normal, but you’re gonna tell us that it’s not normal, theref
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