DOCSLIB.ORG

Fall Sp Target Information

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Fall Sp Target Information FALL SP TARGET INFORMATION MESSIER 13 BASIC INFORMATION OBJECT TYPE: Globular Cluster CONSTELLATION: Hercules BEST VIEW: Late July DISCOVERY: Edmond Halley, 1714 DISTANCE: 25,100 ly DIAMETER: 145 ly APPARENT MAGNITUDE: +5.8 APPARENT DIMENSIONS: 20’ DISTANCE DETERMINATION Globular clusters contain many RR Lyrae stars, which are a type of standard candle. These stars vary in brightness, and the period of variation relates to the star’s luminosity. Comparison of luminosity to apparent magnitude yields the distance. AGE DETERMINATION Astronomers plot the colors and magnitudes of cluster stars on an H-R diagram to get an oVerall picture of the eVolutionary states of the cluster stars. This, in turn, allows astronomers to constrain the age of the cluster. NOTABLE FEATURES/FACTS • M13 contains seVeral hundred thousand stars. Some estimates eVen go as high as one million. • The cluster is estimated to be 12 to 13 billion years old, making it one of the oldest structures in our Galaxy. • M13 contains at least two distinct populations of stars, indicating that the stars formed during multiple episodes. • Many “blue straggler” stars haVe been obserVed in M13. These are stars that appear much younger than the other stars in the cluster, largely due to their blue color. The outer layers of these stars may haVe been stripped away during interactions with other cluster stars, resulting in their blue color. • In 1974, the Arecibo radio telescope was used to send a signal to M13. The signal contained information including descriptions of DNA, human physiology, and our Solar System. If anyone is in M13 to receiVe it, we can expect a reply in about 50,000 years. • Messier added this object to his catalog on 1 June 1764. FALL SP TARGET INFORMATION MESSIER 6 (The Butterfly Cluster) BASIC INFORMATION OBJECT TYPE: Open Cluster CONSTELLATION: Scorpius BEST VIEW: August DISCOVERY: GioVanni Batista Hodierna, c. 1654 DISTANCE: 1600 ly DIAMETER: 12 – 25 ly APPARENT MAGNITUDE: +4.2 APPARENT DIMENSIONS: 25’ – 54’ AGE: 50 – 100 million years DISTANCE DETERMINATION The colors and magnitudes of cluster members are plotted on an H-R diagram. Specific features, such as the location of the main sequence, haVe known theoretical positions on the plot. Comparison of the obserVed position of these features to the theoretical position can yield the distance. AGE DETERMINATION Astronomers plot the colors and magnitudes of cluster stars on an H-R diagram to get an oVerall picture of the eVolutionary states of the cluster stars. This, in turn, allows astronomers to constrain the age of the cluster. NOTABLE FEATURES/FACTS • There is some speculation that Ptolemy obserVed this cluster as early as the 2nd Century A.D. • The “Butterfly Cluster” nickname is attributed to Robert Burnham, Jr., who described the cluster as a “charming group whose arrangement suggests the outline of a butterfly with open wings.” This arrangement is best seen in binoculars. • M6 contains about 80 stars, but some estimate go as high as seVeral hundred. • The brightest star in M6 is an orange supergiant known as BM Scorpii. It is a semi-regular variable whose brightness varies oVer about 1.5 magnitudes. • Charles Messier cataloged this object on the night of 23 May 1764. FALL SP TARGET INFORMATION MESSIER 7 (Ptolemy’s Cluster) BASIC INFORMATION OBJECT TYPE: Open Cluster CONSTELLATION: Scorpius BEST VIEW: August DISCOVERY: Claudius Ptolemy, 130 A.D. DISTANCE: 900 – 1000 ly DIAMETER: 20 – 25 ly APPARENT MAGNITUDE: +3.3 APPARENT DIMENSIONS: 80’ AGE: ~220 million years DISTANCE DETERMINATION The colors and magnitudes of cluster members are plotted on an H-R diagram. Specific features, such as the location of the main sequence, haVe known theoretical positions on the plot. Comparison of the obserVed position of these features to the theoretical position can yield the distance. AGE DETERMINATION Astronomers plot the colors and magnitudes of cluster stars on an H-R diagram to get an oVerall picture of the eVolutionary states of the cluster stars. This, in turn, allows astronomers to constrain the age of the cluster. NOTABLE FEATURES/FACTS • Claudius Ptolemy was first to catalog this cluster, listing it as a “nebula following the sting of Scorpius” in his Almagest. • M7 contains about 80 stars. • The brightest star in M7 is a type G8 yellow giant of magnitude 5.6. • Charles Messier cataloged this object on the night of 23 May 1764. FALL SP TARGET INFORMATION MESSIER 8 (THE LAGOON NEBULA) BASIC INFORMATION OBJECT TYPE: Star Forming Region CONSTELLATION: Sagittarius BEST VIEW: August DISCOVERY: Hodierna, 1654 (nebula) Le Gentil, 1747 (nebula & cluster) DISTANCE: 4000 – 6000 ly DIAMETER: Approximately 130 ly x 60 ly APPARENT MAGNITUDE: +6.0 APPARENT DIMENSIONS: 90’x40’ DISTANCE DETERMINATION Astronomers can identify clusters of stars associated with the nebula, and then plot their colors and magnitudes on an H-R Diagram. Comparing the apparent magnitudes of cluster stars with known absolute magnitudes for giVen points on the diagram can yield the distance. This is very difficult because many stars haVe some leVel of obscuration by the nebula. Thus, the distance to M8 is uncertain. AGE DETERMINATION The presence of features associated with pre-main-sequence stars proVides an upper limit to the age. Astronomers can also plot the colors and magnitudes of nebula stars on an H-R Diagram to get an oVerall picture of the eVolutionary states of those stars and further constrain the age. NOTABLE FEATURES/FACTS • M8 is embedded in a large molecular cloud, a huge complex of cool gas that has the potential to produce thousands of stars. • The energy emitted by the young stars within M8 is responsible for the Visibility of the nebula. Starlight triggers emission in gaseous regions, giVing the nebula its distinctiVe glow. • Most obserVers will see the nebula as mostly gray in color, but some may pick out a green tint. This is due to OIII emission (doubly-ionized oxygen). • The open cluster NGC 6530 is part of the same molecular cloud as M8. The stars of the cluster appear slightly in front of the nebula from our perspectiVe. NGC 6530 contains seVeral hunded stars and is about two million years old. • SeVeral Bok Globules are present in M8. These are collapsing protostellar clouds that appear as dark spots within the nebula. • At the center of M8 lies the Hourglass Nebula. This is the brightest part of M8 and is an actiVe site of star formation. • The Hubble Space Telescope has detected seVeral large, funnel-shaped clouds associated with strong stellar winds in M8. The clouds are 0.5 ly long. • Messier added this object to his catalog on 23 May 1764. FALL SP TARGET INFORMATION MESSIER 20 (THE TRIFID NEBULA) BASIC INFORMATION OBJECT TYPE: Star Forming Region CONSTELLATION: Sagittarius BEST VIEW: August DISCOVERY: Messier, 1764 DISTANCE: ~5200 ly DIAMETER: 42 ly APPARENT MAGNITUDE: +9.0 APPARENT DIMENSIONS: 11’ DISTANCE DETERMINATION Astronomers can identify clusters of stars associated with the nebula, and then plot their colors and magnitudes on an H-R Diagram. Comparing the apparent magnitudes of cluster stars with known absolute magnitudes for giVen points on the diagram can yield the distance. This is very difficult because many stars haVe some leVel of obscuration by the nebula. Thus, there is some discrepancy in quoted distances, but the most frequently adopted value is listed aboVe. AGE DETERMINATION The presence of features associated with pre-main-sequence stars proVides an upper limit to the age. Astronomers can also plot the colors and magnitudes of nebula stars on an H-R Diagram to get an oVerall picture of the eVolutionary states of those stars and further constrain the age. NOTABLE FEATURES/FACTS • The name “Trifid” refers to the three-lobed appearance of the nebula. The lobes are diVided by a dark nebula, known as Barnard 85. • A cluster of young stars is embedded in the central region of the nebula. These stars are estimated to be as young as 300,000 years old. • Most of the emission in the heart of the nebula is attributed to a single O- class star. • M20 contains both an emission and a reflection nebula. The central star has sufficient energy to excite atoms in the gas nearby, but it lacks the energy to prompt emission in the outskirts of the nebula. The outer portion of the nebula glows instead by reflected light. • Messier added this object to his catalog on the night of 5 June 1764. FALL SP TARGET INFORMATION MESSIER 17 (THE SWAN NEBULA) BASIC INFORMATION OBJECT TYPE: Star Forming Region CONSTELLATION: Sagittarius BEST VIEW: Late August DISCOVERY: Philippe Loys deCheseaux, 1745 DISTANCE: 5200 – 6800 ly DIAMETER: 15 – 20 ly APPARENT MAGNITUDE: +6.0 APPARENT DIMENSIONS: 11’ DISTANCE DETERMINATION Astronomers can identify clusters of stars associated with the nebula, and then plot their colors and magnitudes on an H-R Diagram. Comparing the apparent magnitudes of cluster stars with known absolute magnitudes for giVen points on the diagram can yield the distance. ObserVations are made in infrared light because the nebula obscures the cluster stars. This heaVy obscuration makes the distance to M17 uncertain. AGE DETERMINATION Astronomers plot the colors and magnitudes of nebula stars on an H-R Diagram to get an oVerall picture of the eVolutionary states of the nebula stars and constrain the age. As with distance measurements, the dense nebular material makes these obserVations difficult and creates some uncertainty in the age value. NOTABLE FEATURES/FACTS • M17 is known by many names: the Swan Nebula, the Omega Nebula, the Checkmark Nebula, the Lobster Nebula, and the Horseshoe Nebula. • The brightest part of M17 is lit from within by about a dozen O-class stars. These stars are part of a larger cluster of up to 800 stars embedded in the heart of the nebula.
Load more

Recommended publications
  • Eclipse Newsletter
    ECLIPSE NEWSLETTER The Eclipse Newsletter is dedicated to increasing the knowledge of Astronomy, Astrophysics, Cosmology and related subjects. VOLUMN 2 NUMBER 1 JANUARY – FEBRUARY 2018 PLEASE SEND ALL PHOTOS, QUESTIONS AND REQUST FOR ARTICLES TO [email protected] 1 MCAO PUBLIC NIGHTS AND FAMILY NIGHTS. The general public and MCAO members are invited to visit the Observatory on select Monday evenings at 8PM for Public Night programs. These programs include discussions and illustrated talks on astronomy, planetarium programs and offer the opportunity to view the planets, moon and other objects through the telescope, weather permitting. Due to limited parking and seating at the observatory, admission is by reservation only. Public Night attendance is limited to adults and students 5th grade and above. If you are interested in making reservations for a public night, you can contact us by calling 302-654- 6407 between the hours of 9 am and 1 pm Monday through Friday. Or you can email us any time at [email protected] or [email protected]. The public nights will be presented even if the weather does not permit observation through the telescope. The admission fees are $3 for adults and $2 for children. There is no admission cost for MCAO members, but reservations are still required. If you are interested in becoming a MCAO member, please see the link for membership. We also offer family memberships. Family Nights are scheduled from late spring to early fall on Friday nights at 8:30PM. These programs are opportunities for families with younger children to see and learn about astronomy by looking at and enjoying the sky and its wonders.
    [Show full text]
  • MESSIER 13 RA(2000) : 16H 41M 42S DEC(2000): +36° 27'
    MESSIER 13 RA(2000) : 16h 41m 42s DEC(2000): +36° 27’ 41” BASIC INFORMATION OBJECT TYPE: Globular Cluster CONSTELLATION: Hercules BEST VIEW: Late July DISCOVERY: Edmond Halley, 1714 DISTANCE: 25,100 ly DIAMETER: 145 ly APPARENT MAGNITUDE: +5.8 APPARENT DIMENSIONS: 20’ Starry Night FOV: 1.00 Lyra FOV: 60.00 Libra MESSIER 6 (Butterfly Cluster) RA(2000) : 17Ophiuchus h 40m 20s DEC(2000): -32° 15’ 12” M6 Sagitta Serpens Cauda Vulpecula Scutum Scorpius Aquila M6 FOV: 5.00 Telrad Delphinus Norma Sagittarius Corona Australis Ara Equuleus M6 Triangulum Australe BASIC INFORMATION OBJECT TYPE: Open Cluster Telescopium CONSTELLATION: Scorpius Capricornus BEST VIEW: August DISCOVERY: Giovanni Batista Hodierna, c. 1654 DISTANCE: 1600 ly MicroscopiumDIAMETER: 12 – 25 ly Pavo APPARENT MAGNITUDE: +4.2 APPARENT DIMENSIONS: 25’ – 54’ AGE: 50 – 100 million years Telrad Indus MESSIER 7 (Ptolemy’s Cluster) RA(2000) : 17h 53m 51s DEC(2000): -34° 47’ 36” BASIC INFORMATION OBJECT TYPE: Open Cluster CONSTELLATION: Scorpius BEST VIEW: August DISCOVERY: Claudius Ptolemy, 130 A.D. DISTANCE: 900 – 1000 ly DIAMETER: 20 – 25 ly APPARENT MAGNITUDE: +3.3 APPARENT DIMENSIONS: 80’ AGE: ~220 million years FOV:Starry 1.00Night FOV: 60.00 Hercules Libra MESSIER 8 (THE LAGOON NEBULA) RA(2000) : 18h 03m 37s DEC(2000): -24° 23’ 12” Lyra M8 Ophiuchus Serpens Cauda Cygnus Scorpius Sagitta M8 FOV: 5.00 Scutum Telrad Vulpecula Aquila Ara Corona Australis Sagittarius Delphinus M8 BASIC INFORMATION Telescopium OBJECT TYPE: Star Forming Region CONSTELLATION: Sagittarius Equuleus BEST
    [Show full text]
  • Messier Objects
    Messier Objects From the Stocker Astroscience Center at Florida International University Miami Florida The Messier Project Main contributors: • Daniel Puentes • Steven Revesz • Bobby Martinez Charles Messier • Gabriel Salazar • Riya Gandhi • Dr. James Webb – Director, Stocker Astroscience center • All images reduced and combined using MIRA image processing software. (Mirametrics) What are Messier Objects? • Messier objects are a list of astronomical sources compiled by Charles Messier, an 18th and early 19th century astronomer. He created a list of distracting objects to avoid while comet hunting. This list now contains over 110 objects, many of which are the most famous astronomical bodies known. The list contains planetary nebula, star clusters, and other galaxies. - Bobby Martinez The Telescope The telescope used to take these images is an Astronomical Consultants and Equipment (ACE) 24- inch (0.61-meter) Ritchey-Chretien reflecting telescope. It has a focal ratio of F6.2 and is supported on a structure independent of the building that houses it. It is equipped with a Finger Lakes 1kx1k CCD camera cooled to -30o C at the Cassegrain focus. It is equipped with dual filter wheels, the first containing UBVRI scientific filters and the second RGBL color filters. Messier 1 Found 6,500 light years away in the constellation of Taurus, the Crab Nebula (known as M1) is a supernova remnant. The original supernova that formed the crab nebula was observed by Chinese, Japanese and Arab astronomers in 1054 AD as an incredibly bright “Guest star” which was visible for over twenty-two months. The supernova that produced the Crab Nebula is thought to have been an evolved star roughly ten times more massive than the Sun.
    [Show full text]
  • Naming the Extrasolar Planets
    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
    [Show full text]
  • Observer Page 2 of 14
    AAAssstttrrrooonnnooomyyy CCCllluuubbb ooofff TTTuuulllsssaaa OOOOOObbbbbbsssssseeeeeerrrrrrvvvvvveeeeeerrrrrr October 2009 Messier 15 Jean-Dominique Maraldi discovered M15 on September 7, 1746. He described it as 'A nebulous star, fairly bright and composed of many stars'. Charles Messier, who cataloged it on June 3, 1764, and Johann Bode couldn't make this out and described it as 'nebula without stars,' so that it remained to William Herschel in 1783 to resolve this fine star cluster. M15 was the first globular cluster in which a planetary nebula, Pease 1 or K 648 ("K" for "Kuster"), could be identified (Pease 1928, on photographic plates taken at Mt. Wilson in 1927). M15 can be found extremely easily: First find the 2nd magnitude star Epsilon Pegasi, and Theta Pegasi SE of it. Follow the line from Theta over Epsilon and find M15 3 1/2 deg W and 2 1/4 deg N of Epsilon. A 6th magnitude star is about 20' away to the East; another one of magnitude 7.5 is about 5' to the NNE. With its apparent visual brightness of magnitude 6.2, M15 is about at the limit of visibility for the naked eye under very good conditions. The slightest optical aid, opera glass or small binoculars, reveals it as a round nebulous object. It appears as a round mottled nebula in 4-inch telescopes, with at best the very brightest stars visible, but otherwise unresolved in a fine star field. Be sure to catch & log M15 this month! Inside This Issue: Important ACT Upcoming Dates: October Calendar - - - - - - p2 Misc. News - - - - - - - - - - p6 ACT Monthly Meeting @ Bass Pro - Fri, Oct.
    [Show full text]
  • CONSTELLATION VULPECULA, the (LITTLE) FOX Vulpecula Is a Faint Constellation in the Northern Sky
    CONSTELLATION VULPECULA, THE (LITTLE) FOX Vulpecula is a faint constellation in the northern sky. Its name is Latin for "little fox", although it is commonly known simply as the fox. It was identified in the seventeenth century, and is located in the middle of the northern Summer Triangle (an asterism consisting of the bright stars Deneb in Cygnus (the Swan), Vega in Lyra (the Lyre) and Altair in Aquila (the Eagle). Vulpecula was introduced by the Polish astronomer Johannes Hevelius in the late 17th century. It is not associated with any figure in mythology. Hevelius originally named the constellation Vulpecula cum ansere, or Vulpecula et Anser, which means the little fox with the goose. The constellation was depicted as a fox holding a goose in its jaws. The stars were later separated to form two constellations, Anser and Vulpecula, and then merged back together into the present-day Vulpecula constellation. The goose was left out of the constellation’s name, but instead the brightest star, Alpha Vulpeculae, carries the name Anser. It is one of the seven constellations created by Hevelius. The fox and the goose shown as ‘Vulpec. & Anser’ on the Atlas Coelestis of John Flamsteed (1729). The Fox and Goose is a traditional pub name in Britain. STARS There are no stars brighter than 4th magnitude in this constellation. The brightest star is: Alpha Vulpeculae, a magnitude 4.44m red giant at a distance of 297 light-years. The star is an optical binary (separation of 413.7") that can be split using binoculars. The star also carries the traditional name Anser, which refers to the goose the little fox holds in its jaws.
    [Show full text]
  • Wynyard Planetarium & Observatory a Autumn Observing Notes
    Wynyard Planetarium & Observatory A Autumn Observing Notes Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn Tour of the Sky with the Naked Eye CASSIOPEIA Look for the ‘W’ 4 shape 3 Polaris URSA MINOR Notice how the constellations swing around Polaris during the night Pherkad Kochab Is Kochab orange compared 2 to Polaris? Pointers Is Dubhe Dubhe yellowish compared to Merak? 1 Merak THE PLOUGH Figure 1: Sketch of the northern sky in autumn. © Rob Peeling, CaDAS, 2007 version 1.2 Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn North 1. On leaving the planetarium, turn around and look northwards over the roof of the building. Close to the horizon is a group of stars like the outline of a saucepan with the handle stretching to your left. This is the Plough (also called the Big Dipper) and is part of the constellation Ursa Major, the Great Bear. The two right-hand stars are called the Pointers. Can you tell that the higher of the two, Dubhe is slightly yellowish compared to the lower, Merak? Check with binoculars. Not all stars are white. The colour shows that Dubhe is cooler than Merak in the same way that red-hot is cooler than white- hot. 2. Use the Pointers to guide you upwards to the next bright star. This is Polaris, the Pole (or North) Star. Note that it is not the brightest star in the sky, a common misconception. Below and to the left are two prominent but fainter stars. These are Kochab and Pherkad, the Guardians of the Pole. Look carefully and you will notice that Kochab is slightly orange when compared to Polaris.
    [Show full text]
  • Variable Star Section Circular No
    The British Astronomical Association Variable Star Section Circular No. 176 June 2018 Office: Burlington House, Piccadilly, London W1J 0DU Contents Joint BAA-AAVSO meeting 3 From the Director 4 V392 Per (Nova Per 2018) - Gary Poyner & Robin Leadbeater 7 High-Cadence measurements of the symbiotic star V648 Car using a CMOS camera - Steve Fleming, Terry Moon and David Hoxley 9 Analysis of two semi-regular variables in Draco – Shaun Albrighton 13 V720 Cas and its close companions – David Boyd 16 Introduction to AstroImageJ photometry software – Richard Lee 20 Project Melvyn, May 2018 update – Alex Pratt 25 Eclipsing Binary news – Des Loughney 27 Summer Eclipsing Binaries – Christopher Lloyd 29 68u Herculis – David Conner 36 The BAAVSS Eclipsing Binary Programme lists – Christopher Lloyd 39 Section Publications 42 Contributing to the VSSC 42 Section Officers 43 Cover image V392 Per (Nova Per 2018) May 6.129UT iTelescope T11 120s. Martin Mobberley 2 Back to contents Joint BAA/AAVSO Meeting on Variable Stars Warwick University Saturday 7th & Sunday 8th July 2018 Following the last very successful joint meeting between the BAAVSS and the AAVSO at Cambridge in 2008, we are holding another joint meeting at Warwick University in the UK on 7-8 July 2018. This two-day meeting will include talks by Prof Giovanna Tinetti (University College London) Chemical composition of planets in our Galaxy Prof Boris Gaensicke (University of Warwick) Gaia: Transforming Stellar Astronomy Prof Tom Marsh (University of Warwick) AR Scorpii: a remarkable highly variable
    [Show full text]
  • Badw · 003197966
    Abhandlungen der Königlich Bayerischen Akademie der Wissenschaften Philosophisch - philologische und historische Klasse XXX. Band, 1. Abhandlung Antike Beobachtungen farbiger Sterne von Franz Boll Mit einem Beitrag von Carl Bezold , Vorgelegt am 1. Juli 1916 München 1916 Verlag der Königlich Bayerischen Akademie der Wissenschaften in Kommission des G. Franz'schen Verlags (J. Roth) ,. j / Einleitung. Die Geschichte der antiken Astronomie beruhte bis gegen den Ausgang des vorigen Jahrhunderts auf einer Anzahl von griechischen und einigen römischen Schriftstellern, unter denen Claudius Ptolemäus mit seiner "GroElen Syntaxis" als der letzten und um- fassendsten Kodifizierung des antiken Wissens vom Sternhimmel den ersten Platz einnimmt. Auf dem Almagest fuElten einst Delambre und fast drei Menschenalter später Tannery bei ihren Gesamtdarstellungen 1). Es ist klar, daEl mit diesen Quellen auch eine ganz bestimmte Auswahl und Abgrenzung des Stoffes notwendig gegeben war. Nur neues Material konnte aus diesem Bann herausführen. Das hat sich in den letzten zwei Jahrzehnten aus zwei verschiedenen Quellen unerwartet reich eingestellt. Die babylonischen 'rafein, so sporadisch sie immer noch geblieben sind, und so schwierig oft ihre Verwertung ist, geben gute Hoffnung, einmal zu einer von vorgefaElter Meinung nach beiden Seiten unabhängigen Vorstellung von den sachlichen Unterlagen des ionischen Weltbildes im 6. und 5. Jahr- hundert zu gelangen; und die Erforschung der griechischen astrologischen Handschriften, deren überwiegender Teil zum Glück vor
    [Show full text]
  • On the Polar Distances of the Greenwich Transit Circle
    fi 1260-1263. l'he prominence, which iR due in many astronoiiiicsl re- ortlcr to restore this uniforiiiify , which is otiviously of the searches to the long and excellent series of the Greenwich iiiost esseritial iiriporhiicbe, 1 have rel'errctl all the otiser- mericliorial oliservations, gives to any changes of the instrri- vatioiis to the Circle reatlirigs. which corresporrtl to the Naclir nients, by means of which these ohservatioiis are procurecl, observations of the wire. It iiiight have heen tlcsirahle to a higher and more general importance, than they woulcl other- get rid, as much as pnssilile, of' pere~nalecpitions in the wise possess. Hence the interest, with which astrononicrs reading of iiiicroscope - iiiicronieters etc. hy iisiclg for each are wont to regRrtl the construction and cfhiency of any new observer his own Zenithpoints. A closer inspec:tiori sjiotv,, instrunient of superior pretensions, is greatly enhanced in however, that, owing to several ciiwes, this (:nurse is for the case of the powerful Greenwich Transit Circle, and the the past observations inipracticable. I have 'coiiserperitly asiral question, concerning the degree of correctness, which considered it best to adopt the same periods of uri;iltered the results of a new apparatus have attained, acquires addi- Zenithpoints, as have Iieerl used in the Greenwiclr rechictioris. tional claims to be answered. As I an1 not aware, that a The values of the corrections, which it was accordingly seces- strict determination of this point has yet been attempted, 1 sary to apply to the single ohservations, fluctuate I)ct\veeri shall here niake it the suhject of inquiry with reepect to -fO"45 and TO"71.
    [Show full text]
  • Fy10 Budget by Program
    AURA/NOAO FISCAL YEAR ANNUAL REPORT FY 2010 Revised Submitted to the National Science Foundation March 16, 2011 This image, aimed toward the southern celestial pole atop the CTIO Blanco 4-m telescope, shows the Large and Small Magellanic Clouds, the Milky Way (Carinae Region) and the Coal Sack (dark area, close to the Southern Crux). The 33 “written” on the Schmidt Telescope dome using a green laser pointer during the two-minute exposure commemorates the rescue effort of 33 miners trapped for 69 days almost 700 m underground in the San Jose mine in northern Chile. The image was taken while the rescue was in progress on 13 October 2010, at 3:30 am Chilean Daylight Saving time. Image Credit: Arturo Gomez/CTIO/NOAO/AURA/NSF National Optical Astronomy Observatory Fiscal Year Annual Report for FY 2010 Revised (October 1, 2009 – September 30, 2010) Submitted to the National Science Foundation Pursuant to Cooperative Support Agreement No. AST-0950945 March 16, 2011 Table of Contents MISSION SYNOPSIS ............................................................................................................ IV 1 EXECUTIVE SUMMARY ................................................................................................ 1 2 NOAO ACCOMPLISHMENTS ....................................................................................... 2 2.1 Achievements ..................................................................................................... 2 2.2 Status of Vision and Goals ................................................................................
    [Show full text]
  • A Basic Requirement for Studying the Heavens Is Determining Where In
    Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun­ damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short).
    [Show full text]