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Pluto's Long, Strange History — in Pictures : Nature News & Comment
Pluto's long, strange history — in pictures Nature marks the 85th anniversary of the dwarf planet's discovery. Alexandra Witze 18 February 2015 Even at a distance of 5 billion kilometres, Pluto has entranced scientists and the public back on Earth. Nature looks at the history of this enigmatic world, which in July will get its first close-up visit by a spacecraft. First glimpse Lowell Observatory 18 February 1930: Farmer-turned-astronomer Clyde Tombaugh (pictured), aged 24, discovers Pluto while comparing photographic plates of the night sky at Lowell Observatory in Flagstaff, Arizona. The discovery, announced on 13 March 1930, is the culmination of observatory founder Percival Lowell’s obsessive quest to find a ‘Planet X’, the existence of which was suspected based on perturbations in Neptune’s orbit. Name game Galaxy Picture Library 1 May 1930: The Lowell Observatory announces that its favoured name for the discovery is Pluto, suggested by 11-year-old Venetia Burney (pictured) from Oxford, UK, after the Roman god of the underworld. Venetia later becomes the namesake of a student-built dust counter on NASA's New Horizons spacecraft, which is currently on its way to Pluto. Pair bond US Naval Observatory 22 June 1978: James Christy and Robert Harrington, of the US Naval Observatory's Flagstaff Station, discover Pluto’s largest moon, Charon. It is visible as a bulge (at top in left image) that regularly appears and disappears in observational images as the two bodies orbit their mutual centre of gravity1. The moon is so large relative to Pluto that the two are sometimes referred to as a binary planet. -
Winter Constellations
Winter Constellations *Orion *Canis Major *Monoceros *Canis Minor *Gemini *Auriga *Taurus *Eradinus *Lepus *Monoceros *Cancer *Lynx *Ursa Major *Ursa Minor *Draco *Camelopardalis *Cassiopeia *Cepheus *Andromeda *Perseus *Lacerta *Pegasus *Triangulum *Aries *Pisces *Cetus *Leo (rising) *Hydra (rising) *Canes Venatici (rising) Orion--Myth: Orion, the great hunter. In one myth, Orion boasted he would kill all the wild animals on the earth. But, the earth goddess Gaia, who was the protector of all animals, produced a gigantic scorpion, whose body was so heavily encased that Orion was unable to pierce through the armour, and was himself stung to death. His companion Artemis was greatly saddened and arranged for Orion to be immortalised among the stars. Scorpius, the scorpion, was placed on the opposite side of the sky so that Orion would never be hurt by it again. To this day, Orion is never seen in the sky at the same time as Scorpius. DSO’s ● ***M42 “Orion Nebula” (Neb) with Trapezium A stellar nursery where new stars are being born, perhaps a thousand stars. These are immense clouds of interstellar gas and dust collapse inward to form stars, mainly of ionized hydrogen which gives off the red glow so dominant, and also ionized greenish oxygen gas. The youngest stars may be less than 300,000 years old, even as young as 10,000 years old (compared to the Sun, 4.6 billion years old). 1300 ly. 1 ● *M43--(Neb) “De Marin’s Nebula” The star-forming “comma-shaped” region connected to the Orion Nebula. ● *M78--(Neb) Hard to see. A star-forming region connected to the Orion Nebula. -
Photometrie Observations of Minor Planets at ESO (1976-1979) H
found that the S/N ratio of the MMT measurement was nearly the same as in the case of the full aperture. Example 5: Reconstruction of Actuallmages by Speckle Holography Speckle interferometry yields the high resolution autocor relation of the object. It is also possible to reconstruct actual images from speckle interferograms. For that purpose one has to record speckle interferograms of the object one wants to investigate, and simultaneously • speckle interferograms of an unresolvable star close to the • object. The speckle interferograms of the unresolvable star (point source) are used as the deconvolution keys. It is necessary that the object and the point source are in the same "isoplanatic patch". The isoplanatic patch is the field in which the atmospheric point spread function is nearly space-invariant. We found under good seeing conditions the size of the isoplanatic patch to be as large as 22 srcseconds, which was at the limit of our instrument (article in press). The technique of using as the deconvolution keys speckle interferog rams of a neighbourhood point source is called speckle holography. Speckle holography was first proposed by Liu and Lohmann (Opt. Commun. 8,372) and by Bates and co-worker (Astron. Astrophys. 22, 319). Recently, we have for the first time applied speckle holography to astronomical objects (Appl. Opt. 17, 2660). Figure 6 shows an application of speckle holography. In this experiment we reconstructed a diffraction-limited image of Zeta Cancri A-B by using as the deconvolution keys the speckle interferograms produced by Zeta CNC C, which is 6 arcseconds apart from A-B. -
List of Easy Double Stars for Winter and Spring = Easy = Not Too Difficult = Difficult but Possible
List of Easy Double Stars for Winter and Spring = easy = not too difficult = difficult but possible 1. Sigma Cassiopeiae (STF 3049). 23 hr 59.0 min +55 deg 45 min This system is tight but very beautiful. Use a high magnification (150x or more). Primary: 5.2, yellow or white Seconary: 7.2 (3.0″), blue 2. Eta Cassiopeiae (Achird, STF 60). 00 hr 49.1 min +57 deg 49 min This is a multiple system with many stars, but I will restrict myself to the brightest one here. Primary: 3.5, yellow. Secondary: 7.4 (13.2″), purple or brown 3. 65 Piscium (STF 61). 00 hr 49.9 min +27 deg 43 min Primary: 6.3, yellow Secondary: 6.3 (4.1″), yellow 4. Psi-1 Piscium (STF 88). 01 hr 05.7 min +21 deg 28 min This double forms a T-shaped asterism with Psi-2, Psi-3 and Chi Piscium. Psi-1 is the uppermost of the four. Primary: 5.3, yellow or white Secondary: 5.5 (29.7), yellow or white 5. Zeta Piscium (STF 100). 01 hr 13.7 min +07 deg 35 min Primary: 5.2, white or yellow Secondary: 6.3, white or lilac (or blue) 6. Gamma Arietis (Mesarthim, STF 180). 01 hr 53.5 min +19 deg 18 min “The Ram’s Eyes” Primary: 4.5, white Secondary: 4.6 (7.5″), white 7. Lambda Arietis (H 5 12). 01 hr 57.9 min +23 deg 36 min Primary: 4.8, white or yellow Secondary: 6.7 (37.1″), silver-white or blue 8. -
Objects We Observe
Double/Multiple Stars Culpeper Astronomy Club June 18, 2018 Overview • Introductions • Some Telescope Basics • Double Stars • Constellations • Observing Session Aperture Magnification • Magnification for a specific telescope changes with the eyepiece used • Calculated by dividing the focal length (FL) of the telescope (usually marked on the optical tube) by the focal length (fl) of the eyepiece • Mag = FL / fl • For example: • My Stellarvue SV110ED with a 770mm focal length using a 10mm eyepiece produces 77x magnification (770/10=77x) • My 102mm Unitron with a 1500mm focal length using a 10mm eyepiece produces 150x magnification (1500/10=150x) • 30 inch Obsession, f4.5, about 3500mm focal length using 31mm eyepiece produces 112x (3500/31=112x) • Higher the magnification smaller the field of view (FOV) Resolving Power • Resolving power is the ability of an optical instrument to produce separate images of closely placed objects…a double star • In 1867, William Dawes determined the practical limit on resolving power for a telescope, known as the Dawes limit…the closest that two stars could be together and still be seen as two stars • The Dawes Limit is 4.56 seconds of arc, divided by the telescope aperture in inches; converted to metric (approx): PR = 120/DO) • For example, my SV110ED with 110mm aperture (120/110) has a resolving power of 1.09 arc seconds • My 102mm Unitron has a resolving power nearly the same at (120/102) 1.18 arc seconds • The 30 inch Obsession, theoretically, yields 0.16 arc seconds Binary/Multiple Stars – The Motivation -
LOWELL OBSERVATORY in Flagstaff Embodies the Legacy of Arizona's VISIONARY ASTRONOMER
dby eSALLY BsENFORtD /iphontographsaby DAVItD Hi. SMoITH n PERCIVAL LOWELL NEVER CONSIDERED 1966, Lowell Observatory was registered as a LOWELL himself a dreamer. A stargazer, perhaps, but National Historic Landmark. Today, professional OBSERVATORY never a dreamer. and amateur stargazers go to the observatory, In the summer of 1894, Lowell thought he one of the world’s largest, privately operated, in Flagstaff had proof that intelligent life existed on Mars. nonprofit astronomical research observatories. The Harvard-educated mathematician, who Lowell’s 24-inch Clark refractor telescope, Embodies hailed from Boston blue-blooded society, spent which he used for his Mars observations, now the Legacy of night after night perched on a lonely serves as an instrument for public viewing. ponderosa pine-studded mesa above Flagstaff, Even in the 21st century, Lowell seems to Arizona’s gazing through a telescope at Mars, taking oversee the operation as he peers from a large notes and making calculations. By the end of painting that hangs in the observatory’s Steele VISIONARY summer, Lowell decided he had enough Visitor Center lobby. Hand on hip and staring ASTRONOMER information to publish his findings. straight into the future, Lowell stands amid Lowell never proved his theory of life on modern-day and historical space observational Mars, but such theories sparked a firestorm devices. The center serves as the entry point of controversy about Martians, adding a for all observatory programs, telescopes and fascination with space to the developing literary exhibits. People come to learn the observatory’s genre of science fiction. Author H.G. Wells history and for a chance to look through published his novel War of the Worlds in 1898 Lowell’s telescopes. -
Double and Multiple Star Measurements in the Northern Sky with a 10” Newtonian and a Fast CCD Camera in 2006 Through 2009
Vol. 6 No. 3 July 1, 2010 Journal of Double Star Observations Page 180 Double and Multiple Star Measurements in the Northern Sky with a 10” Newtonian and a Fast CCD Camera in 2006 through 2009 Rainer Anton Altenholz/Kiel, Germany e-mail: rainer.anton”at”ki.comcity.de Abstract: Using a 10” Newtonian and a fast CCD camera, recordings of double and multiple stars were made at high frame rates with a notebook computer. From superpositions of “lucky images”, measurements of 139 systems were obtained and compared with literature data. B/w and color images of some noteworthy systems are also presented. mented double stars, as will be described in the next Introduction section. Generally, I used a red filter to cope with By using the technique of “lucky imaging”, seeing chromatic aberration of the Barlow lens, as well as to effects can strongly be reduced, and not only the reso- reduce the atmospheric spectrum. For systems with lution of a given telescope can be pushed to its limits, pronounced color contrast, I also made recordings but also the accuracy of position measurements can be with near-IR, green and blue filters in order to pro- better than this by about one order of magnitude. This duce composite images. This setup was the same as I has already been demonstrated in earlier papers in used with telescopes under the southern sky, and as I this journal [1-3]. Standard deviations of separation have described previously [1-3]. Exposure times varied measurements of less than +/- 0.05 msec were rou- between 0.5 msec and 100 msec, depending on the tinely obtained with telescopes of 40 or 50 cm aper- star brightness, and on the seeing. -
Arizona-Based Astronomers Characterize One of the Smallest Known Asteroids
PRESS RELEASE FOR IMMEDIATE RELEASE: 30 November 2016 ***Contact details appear below*** Arizona-based Astronomers Characterize One of the Smallest Known Asteroids A team of astronomers have obtained observations of the smallest asteroid –with a diameter of only two meters (six feet)—ever characterized in detail. The asteroid, named 2015 TC25, is also one of the brightest near-Earth asteroids ever discovered, reflecting 60 percent of the sunlight that falls on it. Discovered by the University of Arizona’s Catalina Sky Survey last October, 2015 TC25 was studied extensively by a team led by Vishnu Reddy, an assistant professor at the University of Arizona's Lunar and Planetary Laboratory. Other participating institutions include Lowell Observatory and Northern Arizona University. The team used four Earth-based telescopes for the study, published this month in The Astronomical Journal. Reddy argues that new observations from the NASA Infrared Telescope Facility and Arecibo Planetary Radar show that 2015 TC25's surface is similar to a rare type of highly reflective meteorite called aubrites. Aubrites consist of very bright minerals, mostly silicates, that formed in an oxygen-free, basaltic environment at very high temperatures. Only one out of every 1,000 meteorites that fall to Earth belong to this class. "This is the first time we have optical, infrared, and radar data on such a small asteroid, which is essentially a meteoroid," said Reddy. "You can think of it as a meteorite floating in space that hasn't hit the atmosphere and made it to the ground—yet." “2015 TC25 is one of the five smallest Near-Earth Objects ever observed to measure rotation rate” says Audrey Thirouin from Lowell Observatory. -
Percival Lowell Society: Joe Sims Wanted to Be an Astronomer, Maybe Even Belt Asteroids, and Neos
THE LOWELL EXPANDING OUR UNIVERSE OBSERVER The quarterly newsletter of Lowell Observatory Issue 98 Fall 2013 (Right) Nick Moskovitz poses in front Nick Moskovitz of the SOAR 4-m telescope on Cerro Pachon in Chile, where he was Coming to Lowell observing near-Earth asteroids. The by Tom Vitron figure below illustrates the sheer size of various NEOs. The meteor from the Chelyabinsk event was only slightly smaller than the DCT dome, On February 15th, Earth and more than three times as large witnessed two close-up Near-Earth Object as “Big Red”, Percival Lowell’s 1911 (NEO) events, a predicted nearby pass and Model Y Stevens-Duryea touring the Chelyabinsk, Siberia event. Questions car. The Barringer Meteor created Meteor Crater in Arizona, whereas arose immediately: were the two events the Tunguska Comet explosion was related? What kind of meteor was seen the largest impact event on or near brilliantly exploding in the numerous car Earth in recorded history, occurring dashboard videos from Siberia? When the in 1908 near the Podkamennaya world went looking for answers, one of the Tunguska River in Siberia. leading experts quoted was astronomer Nick Moskovitz of MIT, who will be joining Lowell in 2014. “I was at Kitt Peak [National Observatory near Tucson] to see the flyby as we had one chance to try to see it well,” recounts Dr. Moskovitz. “We had some interviews that night about the flyby and [the interviewers] started asking about Chelyabinsk. I hadn’t heard much yet. We were able to see news about the event more 100m 56.3m 50m 18.9m 17m 12.8m 4.9m closely in the night. -
Lowellobserver
THE ISSUE 105 FALL 2015 LOWELL OBSERVER THE QUARTERLY NEWSLETTER OF LOWELL OBSERVATORY HOME OF PLUTO Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the Sun and captured a near- sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon. (NASA/JHUAPL/SwRI) IN THIS SPECIAL EXTENDED ISSUE 2 Director’s Update 2 Trustee’s Update 3 Bound for Chile! New Horizons Unveils Pluto’s Secrets By Will Grundy Astronomers can normally study memes. Importantly, the focus remained distant objects only through their light, so almost entirely on the science, not hare- a unique appeal of solar system science is brained conspiracy theories or umbrage the possibility to send spacecraft to study at off-the-cuff remarks of team members. bodies in ways that could only be done Pluto, the real star of the show, up-close. Such spacecraft exploration isn’t certainly rose to the occasion, revealing 4 Education On Board SOFIA cheap, and competition is fierce over which incredible complexities and stark beauty. missions should be flown. The opportunity But much about the encounter was 5 Pluto Occultation Team to participate in one is a rare and cherished attributable to the hard-working team 6 Lowell Hosts Pluto Palooza opportunity for a planetary scientist like who delivered Pluto to the world. How myself. That’s especially so for a first-ever was this done, and what was it like being encounter with a previously unexplored involved? The key was practice. -
Arxiv:1301.7656V1 [Physics.Hist-Ph]
Origins of the Expanding Universe: 1912-1932 ASP Conference Series, Vol. 471 Michael J. Way and Deidre Hunter, eds. c 2013 Astronomical Society of the Pacific What Else Did V. M. Slipher Do? Joseph S. Tenn Department of Physics & Astronomy, Sonoma State University, Rohnert Park, CA, 94928, USA Abstract. When V. M. Slipher gave the 1933 George Darwin lecture to the Royal Astronomical Society, it was natural that he spoke on spectrographic studies of planets. Less than one–sixth of his published work deals with globular clusters and the objects we now call galaxies. In his most productive years, when he had Percival Lowell to give him direction, Slipher made major discoveries regarding stars, galactic nebulae, and solar system objects. These included the first spectroscopic measurement of the rotation period of Uranus, evidence that Venus’s rotation is very slow, the existence of reflection nebulae and hence interstellar dust, and the stationary lines that prove the existence of interstellar calcium and sodium. After Lowell’s death in 1916 Slipher con- tinued making spectroscopic observations of planets, comets, and the aurora and night sky. He directed the Lowell Observatoryfrom 1916 to 1954, where his greatest achieve- ments were keeping the observatory running despite very limited staff and budget, and initiating and supervising the “successful” search for Lowell’s Planet X. However, he did little science in his last decades, spending most of his time and energy on business endeavors. 1. Introduction Vesto Melvin Slipher, always referred to and addressed as “V. M.” (Giclas 2007; Hoyt 1980b) came to Flagstaff in August 1901, two months after completing his B.A. -
Journey to the Edge of the Solar System
Home / Space/ Special Reports Journey to the edge of the solar system History of a space discovery The existence of a planet beyond the orbit of Neptune had been predicted since the 1840s. Astronomers of the time, in fact, thought there was another large planet as yet unknown, situated on the edge of the Solar System, responsible for the disturbances and changes to the orbits of Uranus and Neptune. Complex mathematical calculations based on the known mass of Neptune showed, in fact, that its orbit, as well as that of nearby Uranus, did not perfectly correspond to the predictions on the motion of bodies in the Solar System. The search for the ninth planet started seriously in the twentieth century. Percival Lowell, founder astronomer (1894) and director of the Observatory in Flagstaff (Lowell Observatory), Arizona, dedicated the last eight years of his life to the search for Planet X, a phrase used to indicate a planet beyond Neptune. Lowell died in 1916, without being able to prove the existence of the missing planet. We had to wait another 14 years and more precisely 18 February 1930 to demonstrate the existence of Planet X. On that day, the twenty four year old Clyde Tombaugh was intent on observing celestial bodies with a blink comparator, an instrument that allows images of the sky obtained at different times to be compared. Clyde Tombaugh, a Kansas farmer with a great passion for astronomy, while never having carried out any formal studies on the subject, had got a job at the Lowell Observatory, thanks to drawings of Mars and Jupiter, which he had made using a telescope he had built with pieces of old farm machinery.