by Paul Gilster | Jan 4, 2011 | Culture and Society |
It’s an interactive morning here in the eastern US, one in which partial solar eclipses can be viewed from more or less anywhere on the planet, asteroids can be chased by school children using data from automatic telescopes in Hawaii, and exoplanet discoveries can be made by gas workers in South Yorkshire. Let’s start with the eclipse, as seen in the image at left that was fed into the Twitterstream by space journalist extraordinaire Daniel Fischer. The accompanying tweet tells us that Fischer was in Aachen with a German TV crew when the photo was made.
Those with unlimited cash can chase eclipses physically, and there is a certain romance in the act, but the real world is made up mostly of those of us who can’t be in the right place at the right time, which is why webcasts from Barcelona to Lahore were worth watching as they covered the event, or tried to. This eclipse was visible to those in Europe, northern Africa and western Asia whose local skies cleared in time to make it viewable, doubly entertaining for those in western Europe for being a sunrise eclipse.
Unfortunately, clouds were widespread over much of northern Europe (though check here for some spectacular shots, including a beauty from Britain’s south coast). But if the average British citizen had little chance to see the eclipse, he or she can still take a certain astronomical satisfaction in the tale of gas worker Peter Jalowiczor, who was recently named as the co-discoverer of four planets: HD31253b, HD218566b, HD177830c and HD99492c. Jalowiczor, an astronomy buff with no telescope of his own, was able to use data supplied by the Lick-Carnegie team, two home computers and plenty of late-night time to make the finds.
You can see the results here, in “The Lick-Carnegie Survey: Four New Exoplanet Candidates,” accepted for publication in The Astrophysical Journal (preprint). It turns out that one of these planets, HD177830c, is usefully located within a binary star system. From the paper:
The RV data we collected for HD 177830 support the existence of an additional inner planet, presenting an interesting case. The planets in this system are within a binary with a separation of approximately 97 AU… Simulations of the formation and stability of planets in binary star systems imply that the perturbative e?ect of the secondary star will be negligible in binaries with separation larger than 100 AU. The binary system of HD 177830 is slightly below this limit. This system is also the ?rst binary with a moderate separation in which multiple planets have been discovered. Although it is unlikely that the low-mass secondary star of this system has had signi?cant e?ects on the formation of planets around the primary, it would still be interesting to study how planets in this system formed and migrated to their current stable orbits.
And in the thick of all this is Jalowiczor, whose name now appears among a distinguished list of planet hunters in a prestigious journal. No wonder he’s overwhelmed, quoted by the Daily Mail as saying: “I’ve always been interested in astronomy and I have two science degrees but to be one of the officially recognised finders of these planets is just… I get lost for words.”
Concurrently, the Pan-STARRS 1 telescope on Haleakala, Hawaii has been the enabler for an eight week asteroid search conducted by school children from the US and Germany that has culminated in the confirmation of four Near-Earth objects and the discovery of more than 170 main belt asteroid candidates. The 60-inch Pan-STARRS 1 uses a 1400 megapixel camera to make more than 500 exposures nightly. Participating schools received Pan-STARRS data over the Internet and examined the imagery for signs of position change among the numerous celestial objects recorded. Four of the NEOs were being observed for the second time, necessary for a confirmation, while 64 more were being studied for the third or fourth time.
Patrick Miller (Hardin-Simmons University, Abilene) is director of the International Astronomical Search Collaboration, which coordinated the recent project:
“Pan-STARRS images contain an amazing amount of data, providing students with opportunities for literally hundreds of new discoveries. With this amount of data, we could expand our campaign to a thousand schools a year, and tens of thousands of students, which is very exciting, and is an unbelievable opportunity for high schools and colleges!”
The 170 main belt asteroid candidates will need to be observed again to be confirmed and some are likely to be previously known objects. But the principle seems clear enough, even beyond the obvious educational value of a search like this. As with the recently discussed Planet Hunters project, the more eyes we get on data, the better.
by Paul Gilster | Jan 3, 2011 | Culture and Society |
If you charted the appearance of certain stars in books through the last two centuries, which ones would get the most hits? It’s an interesting question that Greg Laughlin (UC-Santa Cruz) ponders on his systemic site, using Google’s Ngram viewer as his tool. Ngram lets you plug in the terms of your choice and chart their appearance, using the vast collection scanned into Google Books. When Laughlin plugged in Alpha Centauri, it seemed a safe term to use. The closest star(s) to our own are always going to get a fair amount of attention. He added Proxima Centauri, Beta Pictoris, 51 Pegasi and 61 Cygni.
The chart (shown below) is a bit startling when you realize that the blue spike at its left represents not Alpha Centauri but 61 Cygni, but everything becomes clear when you add in the fact that 61 Cygni was the first star other than the Sun to have its distance measured, making it a major player in 19th Century astronomical references. Greg also reminds us of the Scottish polymath Thomas Henderson, a lawyer and cartoonist who wound up putting his interest in science to good use when his work on measuring longitudes caught the eye of the Royal Navy. He would soon find himself at the Cape of Good Hope, working on parallax measurements of Alpha Centauri.
Henderson pegged the distance to the bright southern star at 3.25 light years, not bad for an early parallax measurement, but he was concerned about the accuracy of his finding and held back long enough for Friedrich Wilhelm Bessel to publish his own parallax measurements of 61 Cygni, which Bessel worked out to be 10.4 light years away (about ten percent less than the true figure). Henderson would publish his work in 1839 but forever lost his chance to be the first to measure the distance to another star. Laughlin’s graph shows the continuing prominence of 61 Cygni in the 19th Century, but Alpha Centauri then moves past it to claim first place.
As to the others, it’s obvious from the chart that 51 Pegasi is a late player, and just as obvious why: It was in 1995, when 51 Pegasi begins to turn up in these references, that Michel Mayor and Didier Queloz announced the discovery of a planet orbiting the star. The duo were working with radial velocity methods at the Observatoire de Haute-Provence, and they had found the first exoplanet around a main sequence star. You can see how useful Google’s Ngram can be at measuring the currency of ideas (and for those of us interested in literary studies, you can see how helpful it is to bring a quantitative analysis tool to the field — see the reference at the end for more on this).
Now 61 Cygni has been on my mind in recent days because one of the books I’m reading is Alastair Reynolds’ Chasm City, a novel in which the planetary system around this star figures as a destination in one of the sub-plots of the book. Reynolds is much taken with ‘generation ships,’ the enormous vessels Les Shepherd talked about in his famous 1952 paper on getting humans to the stars. But the novel also includes later technologies called ‘lighthuggers’ that close to within a small percentage of the speed of light. Here his protagonist looks out on a cluster of starships gathered in the Epsilon Eridani system:
There was something heartbreakingly beautiful about the lights of distant ships… It was something that touched both on human achievement and the vastness against which those achievements seemed so frail. It was the same thing whether the lights belonged to caravels battling the swell on a stormy horizon or a diamond-hulled starship which had just sliced its way through interstellar space.
Caravels? The reference to the technology of Henry the Navigator confirms my suspicion that Reynolds had been reading that wonderful volume Interstellar Migration and the Human Experience before he wrote the book. This collection of essays is the proceedings of the Conference on Interstellar Migration that was held at Los Alamos in 1983, a gathering that was unusually multidisciplinary — biologists came, as did physicists, humanists, philosophers. It remains a classic text that should be on the shelf of anyone following interstellar studies.
Henry, although he did no navigating himself, was obsessed with extending the early journeys of Portuguese sailors further and further down the African coast, financing expeditions and bringing astronomers and cartographers together to work out ways to further the explorations. After Henry’s death in 1460, his successors sponsored still more journeys, using a technology that combined sturdy, ocean-going hulls with lateen sails and a sternpost rudder, a mixture of ship design that drew on northern Europe as well as the methods of Mediterranean sailors. Thus the caravela, which offered a way to beat back home against predominately northerly winds.
Anthropologist Ben Finney presented his thoughts on the caravel at the conference, and went on to speak about the motivational factors that drove visionary explorers in that era:
Without the contributions from the developing scientific and technological movement of the day, Europe could never have resolved its crises through overseas expansion. Exploration and science were intimately linked from the beginning. In fact, the recruitment by Portugal of mathematicians, astronomers and other scientists to help seamen navigate uncharted waters was one of the first, if not the first, major instance in which science was applied systematically to solve a practical problem. Clearly, the technological attitude then developing in the West, with its extreme readiness to apply scientific findings to anything from navigation to gunnery, combined with the search for new sources of wealth to produce European overseas expansion. (p. 204)
Reynolds, whose science fiction offers up star-faring cultures enmeshed in the vast tapestry of space opera, is relating a still medieval technology, one that fed into a renaissance of exploration, to a far future scenario in which humans have crossed gulfs immeasurably greater than those that faced Henry. The question of how to get the thinking of society from here to there is what propels Finney’s analysis. How do we motivate and tune technology to open up such opportunities? Will we be able to make it happen in space?
Having a desirable destination is part of all this. On that score, it’s interesting to return to Laughlin’s analysis. After finishing with Ngram, he goes on to use Google Trends to look at the things we search for online and the volume of news references to those terms. Alpha Centauri shows steady traffic, but Gliese 581 continues to spike. It’s done so three times in the last three years, its spikes aligned with the various claims for habitable planets around the star. The question will face us soon: Exactly how will the public react to the confirmed discovery of a truly Earth-like planet? Will it awaken a new era in exploration that pushes our technologies into interstellar space?
On Ngram and its possibilities, see Michel et al., “Quantitative Analysis of Culture Using Millions of Digitized Books,” published online in Science, 16 December 2010 (abstract). Adrian Berry tells Thomas Henderson’s story in The Giant Leap: Mankind Heads for the Stars (Tor, 2002). For the conference proceedings, see Finney and Jones, Interstellar Migration and the Human Experience, University of California Press, 1985.
