I alluded to this event back in January, and now it's happening (again). Graze on over to Joe Rao's excellent No April Fool's: Moon to Hide the Pleiades Saturday for all the info, including charts of disappearances and reappearances. Looks like the weather is going to cooperate here in KC ...
7/8 April 2006
University of Missouri – Kansas City
Registration: 12:30 – 1:00 pm
Session I: 1:00 – 2:15 pm
Globular Clusters as Probes of the Star Formation History of the Universe
Keith Ashman, University of Missouri – Kansas City
Terrestrial Effects of a 30 pc Supernova
Brian Thomas, Washburn University
Detecting Extrasolar Planetary Transits Through Photoelectric Photometry
Violet M. Poole, Truman State University
Matthew Beaky, Truman State University
Polarization Reverberation Mapping of Active Galactic Nuclei
Masatoshi Shoji, University of Nebraska
Martin Gaskell, University of Nebraska
Rene Goosmann, Astronomical Institute, Academy of Sciences, Czech Republic
Accelerated Expansion in TeVeS
Lado Samushia, Kansas State University
Break: 2:15 – 2:30 pm
Session II: 2:30 – 3:30 pm
Chemical Abundance Patterns of the Milky Way’s Thick Disk: Clues to Formation
Maggie Brewer, William Jewell College
Break: 3:30 – 3:45 pm
Session III: 3:45 – 5:00 pm
Interferometric Parallax: A Method for Measurement of Astronomical Distances
John Ralston, University of Kansas
Under Pressure: Globular Cluster Formation in Dwarf Galaxies
Craig Masters, University of Missouri – Kansas City
Mixture Modeling Analysis of Globular Cluster System Color Distributions
Blake Miller, University of Missouri – Kansas City
The Plot Thickens: Further Observations Hint at a Second R-Process
Debra L. Burris, University of Central Arkansas
J and H Band Photometry of Variable Stars
Break for Dinner
Public Talk by John Rigden at Royall Hall: 8:00 – 9:30 pm
End of Friday Activities
Session IV: 10:00 – 11:00 am
A-Type W Ursae Majoris Binary HH95-79 in Broken Contact
Scott Austin, University of Central Arkansas
Occultation Timing from Crane Observatory
Steven Black, Washburn University
Brenda Culbertson, Washburn University
Neglected Binary Star Parameters Determined from Archival Images and Direct Observation
Chenghu Li, Truman State University
Matthew Beaky, Truman State University
Extended Stromgren Photometry of Melotte 71
B. A. Twarog, University of Kansas
B. J. Anthony-Twarog, University of Kansas
S. Corder, University of Kansas
Break: 11:00 – 11:15 am
Session V: 11:15 am – 12:15 pm
Do Extragalactic Cosmic Rays Induce Cycles in Fossil Diversity?
Mikhail Medvedev, University of Kansas
Break for Lunch: 12:15 – 1:45 pm
Session VI: 1:45 – 3:00 pm
Angular Dependence of Radiation Spectra in GRB Shocks
Sarah Reynolds, University of Kansas
A Chandra, FUSE, Hubble Space Telescope, and Optical Study of the AGN Mrk 279
Martin Gaskell, University of Nebraska
Understanding the Continuum of the Active Galaxy NGC 5548
Elizabeth Klimek, University of Nebraska
Magnetic Helicity Signatures on CMB Anisotropies
Tina Kahniashvili, Kansas State University
Musings on the Redshift of Distant Galaxies
James M. Roe, Astronomical Society of Eastern Missouri
Break: 3:00 – 3:15 pm
Session VII: 3:15 – 4:30
Charge Exchange X-Rays from the Heliosheath
Ina Robertson, University of Kansas
Development of a Littrow Spectrograph
Mary Masterman, Westmoore High School
Combining Traditional Science with Traditional Navajo Beliefs for More Effective Teaching
Paul Temple, Chinle High School
Is the Stromgren c1 Index a Good Luminosity Indicator for GK Dwarfs?
L. C. Vargas, University of Kansas
L. M. Mayer, University of Kansas
B. Twarog, University of Kansas
B. Anthony-Twarog, University of Kansas
Suitability of Caby Photometry for RV Tauri Stars
Scott R. Baird, Benedictine College
End of Meeting
Graze on over to the new Dr Weevil for a sorry tale of extortion, and beware.
Graze on over to NASA's Mini-Comets Approaching Earth for the story; on the weekend of 12-14 May, the fragments of Comet 73P/Schwassmann-Wachmann 3 will pass by Earth at only 25 times the distance to the Moon and will therefore shine as bright as 3rd magnitude, making them visible even from light-polluted urban areas (though binoculars, or driving out of town a ways, will help a lot). Kind of like SL9, but without hitting anything. Like, y'know, us.
Before I get into the details, a great big hat tip to Dave Hudgins of the ASKC.
Specifically, quoting from The t Herculid meteor shower and Comet 73P/Schwassmann–Wachmann 3 (159 kB *.pdf): "On 2006 May 13, as fragment C approaches the Sun, it is expected to pass 0.0735 au from the Earth, with fragments B and E passing even closer (0.0515 and 0.0505 au, respectively)."
I should mention that a glance at the star maps reveals that this is a predawn apparition, so actual observers may be of the somewhat hard-core variety; but there may be a special night/morning or two at Powell Observatory dedicated to the event.
Furthermore, the ASKC's Scott Kranz raves: "Cool!!! On evening of May 7, the comet (at least 1 piece of it) will pass directly in front of the Ring Nebula at 22:04 CDT moving at a whopping 14' per hour at magnitude 7."
This is going to be sweet.
The 36th Annual Mid-American Regional Astrophysics Conference will take place at UMKC in another two weeks (as I type these words, unfortunately while at a venue [scary guy in middle of picture is, um, me] lacking in broadband -- yeah, Clif, I'm rubbing it in). There will be a public lecture at 8 PM on Friday the 7th in Royall Hall (800 E 52nd St), to be given by John Rigden.
For a few nights in early (Northern Hemisphere) spring, it is theoretically possible to see every object in the Messier Catalog in a single night. Weekend after next, starting Thursday evening the 30th and continuing through Sunday the 2nd, the ASKC Dark-Sky Site will be open for ASKC members and their guests to attempt just that.
ASKCer and subject-matter expert Scott Kranz notes: "The only problems I see this year is the young Moon being close to M74 Thursday night. And the Moon being right in the middle of M45 on Saturday night. The stars of M45 are all bright enough though that you should be able to pick them up."
(M74 is a ninth-magnitude, face-on spiral galaxy in Pisces; M45 is rather better known as the Pleiades.)
There are 110 M-objects. Grazing over to the US Naval Observatory's twilight table app and generating a table of astronomical twilight times for Butler, MO -- the nearest town to the dark-sky site (and hometown of RAH), we find a total of 8 hours and 25 minutes of suitably intense darkness on the night of 30/31 March.
That would be a whopping 4 minutes and 35 seconds per object. And new-fangled devices for finding stuff automatically are not allowed. No wonder even the most dedicated amateur astronomers rarely succeed. (Me, I always get lost in the Virgo-Coma Supercluster.)
Via the indispensable Joe Wright of the ASKC ...
Joe, it might be worth notifying some of the ASKC members of an attempt by the GLOBE science group to make simultaneous observations of sky brightness/light pollution around the world during the week of March 22-29. Their observations require no prior experience and can be done from one's own back yard. The results are sent in via the InterNet and will be posted with all the others on a world map.
Thanks for all your good work on behalf of ASKC.
Charles D. Geilker
WJC Physics Dept.
Graze on over and check it out.
I don't do too much of this sort of thing, and try to express more gratitude than anything else when I do -- see, for example, American Christmas. But I was sufficiently charmed by this example to want to pass it along, and it turns out there's a little something for everyone here.
Via John Derbyshire at The Corner, we find the extravagantly, if scripturally, headlined Astronomy illuminates the glory of God. Over at the Templeton Prize website it is simply the Statement by John D. Barrow.
Something for everyone? I note that at the Telegraph site, you can click on through to Wicked Lasers. Heh.
All the cool kids are doing it, so I figure I'd better knock one of these out. Readers, if any remain, of my overwrought treatment of The Substance of Style (Part I; Part II; Part III) would understandably flee this blog right now, so I'll try to be less, well, overwrought in my treatment of An Army of Davids.
American polymath Glenn Reynolds -- there, I said it! He's a polymath! If that isn't good for an Instalanche, nothing is! -- has produced a book whose content should be almost entirely familiar to his regular readers. The challenge for me, as a reviewer, is to add anything of value to what those readers already know. So, a brief list:
But, hey, these are quibbles. I've enlisted. The
Albertian Arcturian Order of Leibowitz, or perhaps the Leibowitzian Order of Arcturus, is a unit of the Reynoldsian Army of Davids.
(Written from Homer's and cross-posted to Chicago Boyz and A Voyage to Arcturus.)
-- is the title of my latest post on Chicago Boyz. Have at it!
-- or, anyway, how to find its possible venues.
An unexpected candidate for extraterrestrial life has appeared in our backyard: it seems that Saturn's moon Enceladus has the highest albedo in the Solar System because "icy geysers at the south pole, erupting from a series of cracks, are pumping a continuous flow of water particles into the area above the moon. Much of the material falls back to the surface as snow."
All other bodies in the Solar System known or believed to have oceans, besides Earth, are large satellites of the outer planets, much larger than our own Moon; but Enceladus is less than 500 kilometers across. Its diameter would fit between KC and Oklahoma City, and its surface area is a bit larger than Texas. Enceladus is not only relatively small, but has a bulk density of only 1.1 g/cm³, so it lacks the radioactive isotopes of heavy metals like those that provide geothermal heat on Earth. And its surface temperature, as derived from the formula in Step 4 of the Energy Balance of the Surface of Early Planets, Radiative Equilibrium Temperature, and Natural Greenhouse Gases page (inputs: Sun's radius, 700,000 km; Sun-Enceladus distance, 1.4 billion km; Sun's surface temperature, 5800 °K), works out to a whopping 92 °K (-181 °C; -293 °F).
So where's the heat source to make liquid water? The obvious candidate is tides. The NinePlanets.org page linked above mentions that Enceladus is in a 1:2 resonance with Dione, and is less than two-thirds the distance from Saturn, whose mass is 95 times Earth's, than the Moon is from Earth. Using the formula given here, namely F ∝ d/R³, however, we find that the tidal force between Saturn and Enceladus is only about four-sevenths that between Earth and the Moon -- but the maximum tidal force between Dione and Enceladus is nearly seven times the Earth-Moon tidal force.
OK, enough fiddling around with the numbers -- want to see it? Graze on over to the Saturn's Moons applet from Sky&Tel. Enter the date and time you'd like to try finding it, keeping in mind that UTC is 6 hours ahead of (for example) CST, then hit "Recalculate using entered date & time."
Print (or sketch) the result. Now you need to find Saturn itself. Unless you already know where it is, I recommend YourSky -- click on "Set for nearby city," choose an appropriate location, and after the map generates, scroll down to "Date and Time." Enter the same time (again in UTC) that you used to generate the Enceladus plot, keeping in mind that the time difference may cause the date to increment as well, and hit "Update." At the moment, Saturn is in Cancer, about 15° southeast of Castor and Pollux in Gemini, which are reasonably obvious by virtue of being two of the brightest stars in the winter sky, and close together. In any case, Saturn itself is brighter than all but a handful of other celestial objects, and being a planet, it doesn't twinkle.
Now you're all set, except for needing 1) a telescope and 2) at least moderately dark skies. Be forewarned that Enceladus isn't the easiest target -- of Saturn's moons, Titan is easy, and Tethys, Rhea, and Dione aren't too difficult, but none of the others make reliable appearances. In the particular case of Enceladus, it's because it's only magnitude +11.8 and is never more than about half of one minute of arc from the planet, which is nearly 30,000 times brighter. In my experience, not only distance from city lights, but good sky transparency and averted vision -- plus a telescope of 6" aperture or more -- are all needed; I've only seen it a few times.
And when you do see Enceladus, it will be a faint little speck you're barely sure is even there. Ponder that in two generations, we've gone from that to this. And be grateful for living in our time.
The far candidate: via Ken Croswell, news of a star that so closely resembles the Sun as to immediately invite speculation:
HD 98618 is 126 light-years from Earth, almost exactly the same distance as Dubhe, the bright star in the Big Dipper that is nearest the North Star.
By comparing HD 98618's spectrum with the Sun's, Meléndez and his colleagues find a near-perfect match. HD 98618's mass is only 2 ± 3 percent greater than the Sun's, its luminosity is only 6 ± 5 percent greater, its temperature is only 66 ± 30 Kelvin greater, and it is 4.3 ± 0.9 billion years old--within the errors, the same as the Sun's age of 4.6 billion years. Furthermore, HD 98618's abundance of heavy, life-giving elements matches the Sun's: its abundance of oxygen is identical, and its abundance of iron is only 11 percent greater.
Of course, many, many other things have to go right for life to be present; see Long Distance Voyager for an attempt at quantifying the likelihood of its appearance. What's neat about this star is that you can see it with relatively little optical aid:
HD 98618 shines so brightly that you don't need a telescope to see it. Instead, binoculars suffice, because its visual magnitude is 7.66. Furthermore, from most of the United States, all of Canada, all of Europe, and most of Japan, HD 98618 is circumpolar--it never sets, so it's visible any time the sky is dark and clear. Its epoch 2000 coordinates are right ascension 11 hours, 21 minutes, 29 seconds; declination +58 degrees, 29 minutes, 4 seconds.
Need a map? Here you go. Looks like it's halfway between Dubhe and Merak -- the "pointer stars" comprising the outer edge of the Dipper -- and a couple of degrees inside the Dipper itself.
Incidentally, if I'm interpreting all this information correctly, HD 98618 is only about 6 light-years from Dubhe, which would shine at magnitude -5, brighter than Venus, in the sky of a hypothetical planet (Dubhe is actually a four-sun system, but would look like two from that distance).
Related post: I blogged about the other best-known solar twin, 18 Scorpii, in The Best Candidate.
Yet another underreported crisis. Hat tip: horseperson of the Arcturcalypse, Troy Funk.
Graze on across the virtual steppe and munch on this.
This is likely to be a continuing series, because I've got a million of 'em.
I actually thought this one up quite a few years ago, but was reminded of it again last Saturday night while looking at Sirius through the main 'scope at Powell Observatory in a vain attempt -- due to the lack of an occulting bar (described here) -- to see Sirius B.
The stated aperture of the Ruisinger (named for the man who did much of the fabrication of the telescope assembly in the mid-'80s) is 30", or about 750 mm. Ignoring the obstruction caused by the spider and secondary mirror, assuming the diameter of the pupil of the human eye to be 7 mm, and also assuming the use of an eyepiece with a similar exit pupil, then the amount of light being gathered is (750/7)² ≈ 11,000 times more than what the unaided eye can gather.
In less technical terms, it's really, really bright. Bright enough to hurt to look at, and piercingly blue-white, thanks to the surface temperature of Sirius, which is 70% hotter than the Sun.
So what would it take to use that illumination, or that of any other bright star, if only for a night light?
First of all, is it reasonable to expect to be able to gather enough light? Let's do the math on that ...
Suppose we want our amplified starlight to be as bright as the Full Moon -- not bright enough to interfere with sleep, but bright enough to read by if you've got good eyes. According to this source, that's ~0.1 lux, or about one-millionth the intensity of direct Sunlight.
-- which, in combination with the inverse-square law, a table of bright stars, and the type of calculation I did above regarding light-gathering power, gives us all the information we need.
Sirius is 8.6 light-years away. The distance from the Sun to Earth is very close to 500 light-seconds, and there are roughly 30 million seconds in a year. That puts Sirius just over half a million times as far away as the Sun. If it were the same brightness as the Sun, we would be getting around 1/260,000,000,000th as much light from it, but it's actually 26 times brighter, so we get one ten-billionth as much. We need that to be one-millionth, that is, amplified by ten thousand. In other words, one hundred times the aperture of the pupil of our eye should do it.
Since that's only 700 mm, and plenty of telescope mirrors are bigger than that, this is clearly at least a theoretically feasible notion.
The problems with it, of course, include 1) making this device affordable for someone other than Bill Gates, since properly-shaped mirrors on the order of a meter in diameter are not cheap; and 2) justifying the use of this capability for something so trivial, lest we end up with the violent wasters.
Fortunately, there is no reason to form an image, so the mirror doesn't need to be a near-perfect paraboloid; it can be mass-produced by spin-casting.
And at the focal point, instead of a secondary mirror or an expensive eyepiece, there is nothing more than a bundle of optical fibers, which pipe the amplified light inside (on clear nights) for use as a conversation piece, night light, etc.
Of course, it would have to be suitably mounted and need a tracking mechanism, but that stuff's getting easier all the time.
So what are you waiting for? Build your own! Or hire me to manage the project and create the next gotta-have accoutrement for people with too much money. Like I say, I've got a million of 'em.
This question came up in a class of 4th-graders to whom ASKCer Neta Apple (previously mentioned in Space, Twenty Years On) gave a presentation earlier today. So, OK, I Googled up a list of first-magnitude stars, from which I eliminated Acrux, b Centauri, and Shaula, and to which I added Polaris. Then I Googled each star name in turn. Ranked from most hits to fewest hits:
The next step, of course, is to do the same thing with the constellations, but there's 88 of those, so it will take rather longer.
Rotation of Earth Plunges Entire North American Continent Into Darkness, reports America's finest news source.
But will the inhabitants burn their cities down just to have light?