21 posts · 19,121 views
The rantings of a postgrad astrochemist. Life, lunacy, academia and the science of all things very big and very small...
Invader Xan
21 posts
Sort by: Latest Post, Most Popular
View by: Condensed, Full
- August 17, 2010
- 12:31 PM
- 414 views
Spaceballs!
by Invader Xan in Supernova Condensate
Causing quite a big stir in the astrochemical world recently is the astronomical detection of C60, more popularly known as fullerene. This is kind of a big deal. Fullerenes have been known about since the 1980s when Harry Kroto et al first5 created them by vapourising graphite with electrical discharges. Since then, it's been found that C60 molecules are very stable and readily formed molecules. Lots of people have hypothesised them existing in space, but up until now there's been no conclusive........ Read more »
Cami, J., Bernard-Salas, J., Peeters, E., & Malek, S. (2010) Detection of C60 and C70 in a Young Planetary Nebula. Science. DOI: 10.1126/science.1192035
- March 1, 2010
- 08:32 AM
- 465 views
Stars Born as Planets
by Invader Xan in Supernova Condensate
Planets are resilient things. They can survive a lot of punishment from their host stars, with some planets having survived being broiled and others even having survived being engulfed as their parent star swells into a red giant. Amazingly, the means by which planets form is no less hardy, for instance being formed in the debris left after a supernova as pulsar planets. So if the method for planet formation is so rugged, what would happen if you started out with an extremely massive star? Could........ Read more »
Amit Kashi, & Noam Soker. (2010) Forming Low Mass Stars and Brown Dwarfs in Protoplanetary Disks of Very Massive Stars. preprint. arXiv: 1002.4693v1
- November 23, 2009
- 12:13 PM
- 579 views
Looking for planets? It's all about the lithium!
by Invader Xan in Supernova Condensate
I have a lot of respect for planet hunters. It's not an easy job. Discovering and confirming the existence of a planet requires a lot of patience, and I'd imagine it must be frustrating at times. So I'm sure a few planet hunters are rejoicing at the news that knowing which stars to look at just became a lot easier. All you have to do is look for lithium.(Read more ...)... Read more »
Israelian, G., Mena, E., Santos, N., Sousa, S., Mayor, M., Udry, S., Cerdeña, C., Rebolo, R., & Randich, S. (2009) Enhanced lithium depletion in Sun-like stars with orbiting planets. Nature, 462(7270), 189-191. DOI: 10.1038/nature08483
- November 12, 2009
- 10:47 AM
- 617 views
Water on the Sun
by Invader Xan in Supernova Condensate
Water is all the rage. It gets mentioned in every single high profile space mission of late. Searching for water on Mars, water inside Europa, water in the atmospheres of exoplanets. Going to the Moon? Don't forget to check for water! All with good reason, of course. Being made of 72.8% water, it's rather important that wherever we might go in the Universe, we have a ready supply of it. But water's been found in some surprising places.(Read more ...)... Read more »
Wallace L, Bernath P, Livingston W, Hinkle K, Busler J, Guo B, & Zhang K. (1995) Water on the sun. Science (New York, N.Y.), 268(5214), 1155-8. PMID: 7761830
Polyansky, O. (1997) Water on the Sun: Line Assignments Based on Variational Calculations. Science, 277(5324), 346-348. DOI: 10.1126/science.277.5324.346
- September 9, 2009
- 01:01 PM
- 537 views
Looking for moons with Kepler's eyes...
by Invader Xan in Supernova Condensate
The idea that moons around exoplanets could be host to life is certainly not a new one. Thanks to Star Wars (and Ewoks), the idea of habitable moons is quite deeply embedded into sci fi pop culture -- and as with so many things in the wonderful world of astronomy, both serious science and science fiction have given a lot of thought to the idea ever since. Being as we have a distinct shortage of Millennium Falcons to use, however, the difficult part is actually finding these moons.(Read more ........... Read more »
David M. Kipping, Stephen J. Fossey, & Giammarco Campanella. (2009) On the detectability of habitable exomoons with Kepler-class photometry. Monthly Notices of the Royal Astronomical Society (accepted). arXiv: 0907.3909v2
- August 7, 2009
- 03:45 PM
- 658 views
Cthonian Ftargn!
by Invader Xan in Supernova Condensate
Cthonian planets are an interesting little concept. I'm not talking about the planet Vhoorl, either, despite any similarities to the name of a certain "Great Old One". Instead, cthonian planets (a name coined by the authors of this paper) bear their name in reference to ancient greek gods who came from the hot infernal underground, and the origins of these worlds are no less hellish. Former gas giants which ventured too close to their star, these are planets whose atmosphere has actually boiled........ Read more »
G. Hébrard, A. Lecavelier des Étangs, A. Vidal-Madjar, J. -M. Désert, & R. Ferlet. (2003) Evaporation rate of hot Jupiters and formation of Chthonian planets. Extrasolar Planets: Today and Tomorrow, ASP Conference Proceedings. arXiv: astro-ph/0312384v1
- July 14, 2009
- 03:30 PM
- 797 views
How to spot exo-Earths...
by Invader Xan in Supernova Condensate
It seems like we're not going to stop discovering new exoplanets anytime soon. Around one sixth of all exoplanets currently known can be observed transiting their star's disk. Given that transits are precisely what NASA's Kepler mission is going to spend the next three years looking for, that number is certainly set to increase over the coming months. But with exoplanet transits comes a unique opportunity to study them...(Read more ...)... Read more »
Pallé, E., Osorio, M., Barrena, R., Montañés-Rodríguez, P., & Martín, E. (2009) Earth’s transmission spectrum from lunar eclipse observations. Nature, 459(7248), 814-816. DOI: 10.1038/nature08050
- June 25, 2009
- 03:29 PM
- 732 views
Life in the smoggy freezer?
by Invader Xan in Supernova Condensate
The twin questions of how and where life could begin from prebiotic chemistry are pretty big ones. Indeed, despite the now famous Miller-Urey experiment created amino acids by zapping simple chemicals with lightning bolts, we're not much closer to a proper answer for that question. A good place to look for answers though, is Titan. Out on Titan, methane acts like water does on Earth, and the mountains are made from ice and not silicates. Despite these outlandish differences, many believe that th........ Read more »
Pilling, S., Andrade, D., Neto, A., Rittner, R., & Naves de Brito, A. (2009) DNA Nucleobase Synthesis at Titan Atmosphere Analog by Soft X-rays . The Journal of Physical Chemistry A, 2147483647. DOI: 10.1021/jp902824v
- May 29, 2009
- 04:09 PM
- 847 views
You are now leaving the Milky Way
by Invader Xan in Supernova Condensate
It's bad luck if a black hole crosses your path. Actually it's very bad luck, particularly if you happen to be a star like SDSS J090745.0+024507. Known by some as "The Outcast Star", it had the misfortune around 80 million years ago of straying a little too close to Sagittarius A*, our galaxy's resident supermassive black hole. Subsequently it was flung outwards at a blistering speed, and it's been travelling ever since. In fact, it's in the process of leaving the galaxy!(Read more ...)... Read more »
Brown, W., Geller, M., Kenyon, S., & Kurtz, M. (2005) Discovery of an Unbound Hypervelocity Star in the Milky Way Halo. The Astrophysical Journal, 622(1). DOI: 10.1086/429378
Cesar I. Fuentes, K. Z. Stanek, B. Scott Gaudi, Brian A. McLeod, Slavko B. Bogdanov, Joel D. Hartman, Ryan C. Hickox, Matthew J. Holman. (2008) The Hypervelocity Star SDSS J090745.0 024507 is a Short-Period Variable. arXiv/astro-ph. DOI: 0507520
- April 14, 2009
- 06:27 PM
- 998 views
How different could life be under a red dwarf sun?
by Invader Xan in Supernova Condensate
I've been mulling over this paper for a few days now. Last week, NASA JPL put out a press release about cool stars having a different mix of life forming chemicals to sun-like stars. The release was immediately picked up by news sites and bloggers alike. With good reason too -- the findings could have a lot of implications for future astrobiology searches. With my interest piqued, I thought I'd get hold of a copy of the paper and find out more...(Read more ...)... Read more »
I. Pascucci, D. Apai, K. Luhman, Th. Hemming, J. Bouwman, M. R. Meyer, F. Lahuis, A. Natta. (2009) The Different Evolution of Gas and Dust in Disks around Sun-like and Cool Stars. Astrophysical Journal (submitted). DOI: http://arxiv.org/abs/0810.2552v2
- April 8, 2009
- 07:56 PM
- 1,080 views
The Thermodynamics of Life
by Invader Xan in Supernova Condensate
Now I'm a big fan of alternative biochemistry theories in the search for extraterrestrial life. It seems logical to think that given the size of the universe and the number of possible environments out there, life might have found more than one way to organise itself. However, thanks to some clever thermodynamics, it looks quite likely that at least some alien life out there might not be so "alien" after all...(Read more ...)... Read more »
Paul G. Higgs, Ralph E. Pudritz. (2009) A thermodynamic basis for prebiotic amino acid synthesis and the nature of the first genetic code. Astrobiology (accepted). DOI: 0904.0402v1
- February 28, 2009
- 03:46 PM
- 1,085 views
α's always welcome at the helium party!
by Invader Xan in Supernova Condensate
I stumbled upon a fascinating paper on arXiv the other day. Anyone who works with lasers should be familiar with the concept of stimulated emission - the means by which photons excite electrons which, in turn, emit more photons (identical, in phase, energy and velocity, to the original photon). But could you elicit a similar effect with nuclear decay? Specifically, can you make α decay happen?(Read more ...)... Read more »
A. L. Barabanov. (2009) Is it possible to stimulate nuclear alpha decay by superfluid helium?. preprint. DOI: 0902.4628
- February 25, 2009
- 12:00 AM
- 1,089 views
Life in the clouds?
by Invader Xan in Supernova Condensate
As a lot of people will know by now, the human race is officially going back to Jupiter and its moons. It's currently scheduled to get there by about 2026. I'm seriously looking forward to it, myself. There's an awful lot about our friendly neighbourhood giant that we still don't really understand. In honour of this, I decided to take a look at a classic paper written by Carl Sagan and Edwin Salpeter on the fascinating possibility of life and possible ecologies on a hulking gas giant like Jupite........ Read more »
C. Sagan, & E. E. Salpeter. (1976) Particles, environments, and possible ecologies in the Jovian atmosphere. The Astrophysical Journal Supplement Series, 737. DOI: 10.1086/190414
- January 18, 2009
- 05:47 PM
- 1,081 views
How chemists can help astrobiologists...
by Invader Xan in Supernova Condensate
Quite a puzzler in astrochemistry and astrobiology is where exactly prebiotic amino acids form. We know they can form in interstellar space. We've found them inside chondritic meteorites. All the ingredients exist in the interstellar medium. There have even been reports of glycine detected in interstellar space. On the other hand, those reports are still unverified. But are we really looking for the right thing...?(Read more ...)... Read more »
M. Lattelais, Y. Ellinger, & B. Zanda. (2007) Theoretical study of prebiotic precursors-2: about glycine, its N-carboxyanhydride and their protonated ions. International Journal of Astrobiology, 6(01), 37. DOI: 10.1017/S1473550406003521
- January 10, 2009
- 12:00 AM
- 1,112 views
Extragalactic molecules!
by Invader Xan in Supernova Condensate
When I saw this paper's title I was intrigued. When I realised what this paper was actually about, I was genuinely enthralled! A couple of months ago, I was wondering whether it would be possible to take a gamma ray burst spectrum and look for interstellar chemicals. Well, now someone has! And they've got the first concrete observations of molecules in a redshifted GRB host galaxy!(Read more ...)... Read more »
J. X. Prochaska, Y. Sheffer, D.A. Perley, J. S. Bloom, L. A. Lopez, M. Dessauges-Zavadsky, H.-W. Chen, A. V. Filippenko, M. Ganeshalingam, W. Li.... (2009) The First Positive Detection of Molecular Gas in a GRB Host Galaxy. Astrophysical Journal Letters (accepted). DOI: arXiv:0901.0556v1
- December 30, 2008
- 12:00 AM
- 1,165 views
Could we help The Sun cheat death?
by Invader Xan in Supernova Condensate
Since they were first discovered in 1952, blue stragglers have baffled astronomers. Appearing strangely youthful amid their ageing brethren, many now believe blue stragglers are formed when two smaller stars merge. There is, however, one theory which is rather more... outlandish. In a fascinating paper dating back to 1990, Martin Beech suggests an alternative explanation. What if an advanced civilization, having invested so much time and effort into their home star system, decided to artificiall........ Read more »
Martin Beech. (1990) Blue stragglers as indicators of extraterrestrial civilisations?. Earth, Moon and Planets, 49(2), 177-186. DOI: 10.1007/BF00053979
- December 24, 2008
- 07:01 AM
- 1,216 views
A Simple Kind of Life
by Invader Xan in Supernova Condensate
As any astrochemist will tell you without hesitation, polycyclic aromatic hydrocarbons are important molecules to study, because they're directly relevant to the origins of life. We tend to repeat this like a mantra, and perhaps we don't always fully appreciate the ramifications of what we're saying. Contentious, hotly debated and under researched, the origin of life is a difficult and heavily transdisciplinary subject. It's also a long standing fascination of mine, and the main reason I went in........ Read more »
Pascale Ehrenfreund, Steen Rasmussen, James Cleaves, & Liaohai Chen. (2006) Experimentally Tracing the Key Steps in the Origin of Life: The Aromatic World. Astrobiology, 6(3), 490-520. DOI: 10.1089/ast.2006.6.490
- December 22, 2008
- 12:00 AM
- 1,211 views
Protonation's what you need
by Invader Xan in Supernova Condensate
Ah, the humble proton. Simple, stable, and able to drastically affect the chemistry of other molecules -- and nowhere more so than in the Interstellar Medium (ISM). H2 molecules, for instance are readily protonated in dense interstellar clouds, forming H3+, and playing a key role in the formation of hydrides like ammonia and methane. CO forms HCO+, N2 forms HN2+ and so on. So what about those PAH molecules I keep talking about...?(Read more ...)... Read more »
A. Pathak, & P. J. Sarre. (2008) Protonated PAHs as carriers of diffuse interstellar bands. Monthly Notices of the Royal Astronomical Society: Letters. DOI: 10.1111/j.1745-3933.2008.00544.x
- December 4, 2008
- 12:00 AM
- 1,136 views
Could life have evolved closer than we thought?
by Invader Xan in Supernova Condensate
Traditionally, anyone seriously researching extraterrestrial life has tended to ignore red dwarfs. Typically a disproportionately low number have been included in SETI searches, for instance. They're troublesome, ill-tempered little things which like to randomly flare up for seemingly no reason. Small, cool and difficult to spot, relatively few red dwarfs can even be seen from Earth because they're so faint. Their violent tantrums cause huge flares far more powerful than anything the Sun could p........ Read more »
Jill C. Tarter, Peter R. Backus, Rocco L. Mancinelli, Jonathan M. Aurnou, Dana E. Backman, Gibor S. Basri, Alan P. Boss, Andrew Clarke, Drake Deming, Laurance R. Doyle.... (2007) A Reappraisal of The Habitability of Planets around M Dwarf Stars. Astrobiology, 7(1), 30-65. DOI: 10.1089/ast.2006.0124
- November 26, 2008
- 12:00 AM
- 1,242 views
Why Space Should Taste Like Strawberries...
by Invader Xan in Supernova Condensate
Glycolaldehyde is what everyone's talking about. And when I say everyone, what I really mean is some astrochemists.... Read more »
M.T. Beltran, C. Codella, S. Viti, R. Neri, R. Cesaroni. (2008) First detection of glycolaldehyde outside the Galactic Center. Astrophysical Journal Letters (preprint). DOI: 0811.3821v1
topics
join us!
Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.
If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.
