Buffer Me

Wednesday, March 20, 2013


The rogue planet: a short science "crime" story 
(written in Eng?ish)  

Listen to the podcast episode
on Itunes
on Podcast Machine

The place: Sheriff Cosmo's office. 
The characters: cop1 (Sheriff Cosmo); cop2 (Agent McSpace); cop3 (Agent 'CSI' Stern); the rogue planet (CFBDSIRJ214947.2-040308.9); the gang (AB Doradus moving group). 
The background: a group of concerned good citizens – a bunch of astronomers from France and Canada - has reported to the authorities the presence of a suspicious planet which is roaming alone in the interstellar space something like 80-160 light years from Earth. The international group of geeks has snitched last september when its members published a research paper on the journal 'Astronomy&Astrophysics'.
After a long chase, Scheriff Cosmo's men have apprehended the rogue planet, the charge being vagrancy and possession of a false ID card. 
The scene: Agent McSpace and Agent 'CSI' Stern are reporting to Sheriff Cosmo.

A cartoon: the rogue planet lost in space complaining about the bad quality of Apple maps (by sciencemug)
The rogue planet (by sciencemug)
[The picture is adapted from a Public Domain image by sciencemug (source: Wikimedia Commons)]

Agent McSpace- ... It was wandering as reported, besides the suspect had an ID card which stated that it is a brown dwarf, but that's false... 
Sheriff Cosmo- If it's not a brown little cosmic body – I think they prefer to be called like this, McRude – what is it our prisoner? 
Agent 'CSI' Stern- It is probably a 4−7 Jupiter mass free-floating planet with a temperature of about 700 K and a log g of about 4.0, Sheriff. 
SC- Translate for the non-brains, please... 
CSI- Essentially it's not a brown dw... little cosmic body, Sir, but a ball of gass 4 to 7 times more massive than Jupiter, thus 1300 to 2200 times more massive than the Earth, but anyway 4200 to 7300 times less massive than the Sun. 
SC- Ok, in short a big guy among planets and a loser among stars. 
CSI- More or less Sir. 
SC- Go on, what about all those strange parameters you mentioned. 
CSI- What, the temperature and the log g? 
SC- Yeah, that stuff. 
CSI- Well, Sir, the surface temperature of the prisoner is about 700 Kelvin... 
SC- Hey CSI, I'm a Fahrenheit guy... 
CSI- Sorry Sir, it means a bit more than 800 °F. 
McS- Ahem... 
SC- Yes Agent McSpace? 
McS- I'm european on my mother's side, Sir... 
SC- So? 
McS- Well, Sir, I was born and raised according to the SI system... 
SC- Oh for Newton's sake... ok, Stern, convert that Kelvin thing into... what is it McSI? 
McS- Celsius Sir, thank you Sir. 
Stern looks at McSpace and, with a hint of condescension, says- It's a bit less than 430 °C, McEuropean. This means that our prisoner's surface temperature is 8 times lower than our Sun's one, while it's similar to that of Mercury and about 5 times higher then the Jupiter's one. 
SC- What about the log g 4 matter? 
CSI- Oh, right Sir. Log g 4 means that the prisoner's surface gravity is about 10 times higher than Earth's gravity, Sir. 
SC- Gotcha. Anyway, how come that we made acquaintance with this hobo full of gas?
McS- We were 'introduced' each other by Doc Delorme...
SC- Who?
McS- You know him Sir, remember? He's the guy who organized the surveillance initiative we authorized a while ago, the 'Canada-France Brown Dwarfs Survey which searches the sky also in the infra-red wavelenght (CFBDIR)'. He and his pals full of good will contacted us because, during one of the patrols in their space-block, they spotted a cosmic body that was floating alone.
SC- Aah right, right... So our prisoner was, is that body. I see... Well, nothing like a fistful of zealous astronomers to keep our asses informed about the sky, don't you think?
McSpace and Stern smile while nodding.
SC- Anything else gentlemen?
McS- Yes Sir. The prisoner could be affiliated with a gang, the 'AB Doradus moving group'.
CSI- Actually there's an 87% probability of such an affiliation, Sir – points out Stern pretending not to notice McSpace's eye-rolling.
McS- The gang is formed by about thirty co-moving stars. Its leader's a physco, it's been diagnosed with a personality disorder, it's infact a trinary star* (1)... Full name's 'AB Doranus' but everybody calls it 'AB Dor'. It and its other fellas have been spotted for the first time in 2004.
SC- By who, still nosy civilians?
McS- Yes Sir, three space-voyeurs from USA and Australia... They gave us the information in exchange of a one-year free supply of donuts, a pile of autographed pictures of Stephen Hawking and a paper published on 'The Astrophysical Journal'**.
SC- Uhm, fair deal, I'd say... Ok then, these gangsta-moving stars, where do they usually hang out?
CSI- Many of the AB Dor's group members can be found in the northern hemisphere. They are about 15-20 parsec (48-65 light years) away from us, Sir, partially surrounding our Sun (1-2).
SC- Do you think they can become a problem?
McS- No Sir, they're just some random 50-120 million years old youngsters (1). Basically it's only a small flock of star-kids who waste their time loitering around together in the universe.
SC- And our prisoner, how old is it?
CSI- Well, its ID card says it's 20-200 million years old. Anyway it must be 50-120 million years old too, since it's most probably one of the AB Dor's affiliates and they accept only people of their age. 
Sheriff Cosmo stops swinging on his chair and stands up- Alright gentlemen, take the spectral fingerprints of this spherical cosmic little fart, take its mugshot too and file it as 'CFBDSIRJ214947.2-040308.9'. Once the paper work's done, kick the tramp out of here with a warning, there's no point in keeping it in at the expense of the state.
McS- Yes Sir.
CSI- Indeed Sir...
SC- What is it Stern? 
CSI- Well Sir, it would be important for us to collect as much information as possible about our guest. We could use it as a benchmark for understanding the physics of the similar [..] type of exoplanets. 
SC- Go on CSI.
CSI- Astronomers are planning and building a new generation of instruments to look for exoplanets and the universe seems to be plentiful of isolated planetary mass objects (IPMOs) like our prisoner. We know now that IPMOs can be the result of stellar formation processes and/or planets ejection from their host star, moreover young IPMOs of a few Jupiter masses -again, like our prisoner- would be interesting analogues of the exoplanets these instruments*** will be build up to detect.
SC- In other words the more we know about the prisoner, the better chance we have to fine tune our state-of-the-art tools, the easier hunting exoplanets is going to be.
CSI- Right, Sir.
McS- I respectfully disagree by your enthusiasm. Hunting is a cruel activity... 
At this point Sherif Cosmo and Stern slowly turn toward McSpace, they curl their eybrows as if to say 'Did you really just said that, McDumbass?!' and then, just as slowly, they start talking again.
SC- Ok Stern, you have till sunset, then we let it go back to the sky. 
CSI- Yes sheriff, thank you Sir.
SC- Now go, both of you, I have a meeting with the Mayor in 5 minutes, we have to discuss about the organization of the incoming Carnival Parade. This year the theme is: "The bonobos meet the spread while the honeybooboos introduce themselves to the fiscal cliff".

The underlined sentences are quotations from the paper by Delorme et al.

* I.e. a triple star system, that consists of three stars orbiting each other and that are bound by gravitational attraction.
** Of course only the story about the donuts is true...

- Delorme, P., Gagné, J., Malo, L., Reylé, C., Artigau,E., Albert, L., Forveille, T., Delfosse, X., Allard, F., and D. Homeier (2012). CFBDSIR2149-0403: a 4–7 Jupiter-mass free-floating planet in the young moving group AB Doradus? Astronomy & Astrophysics 548. (PDF version here)

1- Ortega, V. G., Jilinski, E., De La Reza,R., and Bazzanella, B. (2007). On the common origin of the AB Doradus moving group and the Pleiades cluster. Monthly Notices of the Royal Astronomical Society 377, 441-445.
2- Zuckerman, B., Song I., and Bessell, M.S. (2004). The AB Doradus Moving Group. The Astrophysical Journal Letters 613.

No comments:

Post a Comment

Thanks for your comment dear reader!