DOCSLIB.ORG

The Night Sky the Newsletter of the Astronomy Club of Akron

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Night Sky the Newsletter of the Astronomy Club of Akron The Night Sky The Newsletter of The Astronomy Club of Akron www.acaoh.org Volume 36 Number 1 January 2014 Next Meeting: Friday - January 24 , 2014 - 8:00 PM - Kiwanis The President’s Column Betelgeuse were to replace the Sun in Earth with a distance of 1344 light By Gary Smith the center of the solar system, its years. M42 is so bright that colors surface would extend past the asteroid may be seen through the eyepiece of a Hello to all fellow sky watchers. belt possibly to the orbit of Jupiter. large amateur telescope (approx 24- The January sky is truly a sight-to- Due to certain physical characteristics 26inch diameter). Astrophotography behold. From the Earth-bound of Betelgeuse and stars like of M42 reveals three colors. There is perspective it would seem the winter Betelgeuse, its mass is estimated to be a distinctive greenish tint that proved sky received more than a fair share of between 5 to 30 solar masses. Its to be a mystery until the early part of celestial delights. I think it is safe to distance is likewise an estimate at 640 the twentieth century. The green color say the constellation of Orion (the light years. is caused by a low probability hunter) is the most easily recognized electron transition in doubly ionized constellation today and throughout Beta Orionis (Rigel) has an oxygen. M42 also displays a red hue. human history. apparent magnitude of 0.12 and is the This is a well understood seventh brightest star in the sky. It recombination line radiation of In days not long past, most also easily displays its blue-white Hydrogen alpha at 656.3nm. The third publications would print all color in even dismal viewing color is a blue-violet color due to astronomical photographs in black conditions. The stellar characteristics reflected radiation from massive and and white. The venerable amateur of this remarkable star are almost too very energetic O-class stars at the astronomer’s monthly publication, numerous to list. Rigel is a triple star core of the nebula. Sky & Telescope, would typically system with Rigel A as the dominant print only a color cover. All else component with an absolute The mythological drawing of printed in the magazine was black magnitude of –7.84, approximately Orion the hunter will easily show its and white. Advances in color 130,000 times the brightness of the component features. reproduction gave rise to a thriving Sun. Rigel A is a blue supergiant star 1) The Belt of Orion is composed of market for color astronomical posters. with about 18 solar masses and an three stars of very similar brightness The constellation Orion predates the approximate distance of 860 light that are evenly spaced and appear to transition of black & white years. lie on a nearly straight line. photographs giving way to color 2) The Head. Three stars compose a images. Alpha Orionis (Betelgeuse) One of the many highlights of the small triangle that marks the head of has an apparent magnitude of 0.42 constellation Orion is the Great Orion Orion. At the apex of the triangle is a and is the ninth brightest star in the Nebula (M42). It is a spectacular hot blue giant star named Meissa. The sky. Even under less than ideal diffuse nebula located south of two stars that comprise the base of the viewing conditions it is easy to see the Orion’s Belt. This bright nebula is triangle are Phi-1 and Phi-2. reddish color. Betelgeuse is not an visible to the unaided eye and is a 3) North Arrow. Together with the ordinary star. It is a red supergiant magnificent object for both binoculars three stars of Orion’s belt, Eta Orionis star and is one of the largest and most and small telescopes (larger forms the head of an arrow. M42 and luminous of the bright stars in the telescopes capable of a wide-field of M43 are at the lower end and form the observable sky. The diameter of view are ideal). M42 is the closest tail of the arrow. Betelgeuse is remarkable. If region of massive star formation to (Con’t Page 5) OFFICERS 2012 – 2014 President Gary Smith Phone: 330-633-9873 E-mail: [email protected] Vice President Anthony Scarpitti E-mail: [email protected] Treasurer Glenn Cameron E-mail: [email protected] Secretary Juan Contreras E-mail: [email protected] Assistant Secretary/Treasurer Ann Ferrell E-mail: [email protected] Observatory Director Ron Kalinoski Phone: 330-837-5848 ACA Webmaster Dave Jessie E-mail: [email protected] Publications Secretary - Editor, Night Sky Newsletter Jason Shinn Phone: 330-685-5382 E-mail: [email protected] Trustee Lewis Snodgrass E-mail: [email protected] Trustee John Shulan Phone: 330-836-0800 E-mail: [email protected] Statutory Agent Mark Kochheiser Phone: 330-882-3713 E-mail: [email protected] OTAA Representative Lou Poda 2 November Treasurer’s Report December Treasurer’s Report By Glenn Cameron By Glenn Cameron 11/1/2013 Through 11/30/2013 12/1/2013 Through 12/31/2013 Checking Beginning Balance $2,231.84 Checking Beginning Balance $2,231.84 Income Income 0.00 Dues 120.75 Magazine Subscriptions 32.95 Total Income $0.00 Total Income $153.70 Expenses Expenses 0.00 Newsletter Expenses -15.80 Magazine Subscriptions -32.95 Total Expenses $0.00 Total Expenses -$48.75 Income Less Expenses $0.00 Income Less Expenses $104.95 Checking Ending Balance $2,231.84 Checking Ending Balance $2,336.79 Savings Beginning Balance $2,500.67 Savings Beginning Balance $2,500.77 Earned Interest 0.10 Earned Interest 0.11 Savings Ending Balance $2,500.77 Savings Ending Balance $2,500.88 Petty Cash Beginning Balance $59.55 Petty Cash Beginning Balance $59.55 0.00 0.00 Petty Cash Ending Balance $59.55 Petty Cash Ending Balance $59.55 Petty Cash 59.55 Petty Cash 59.55 Savings 2,500.77 Savings 2,500.88 Checking 2,231.84 Checking 2,336.79 Grand Total $4,792.16 Grand Total $4,897.22 Article by Glenn Cameron Article by Glenn Cameron ACA Treasurer. ACA Treasurer. 3 SWAP & SHOP For sale: 15mm Ultra-Wide Angle Eyepiece Asking: $40 Contact: Lew Snodgrass Phone: 330-819-4886 Phone: 330-867-4800 Ask for Lew. Email: [email protected] For Sale: Pentax XW 20mm Eyepiece Excellent condition. Small mark on 1.25” barrel. Always used in a compression clamp. Asking: $220 (cash) Contact: Fred Fry Email: [email protected] For Sale: Meade LXD75 mount, tripod, and one counterweight. For sale: Includes Autostar and battery box power supply. Also Teleview Radian 12 mm includes cigarette lighter power cable. Works fine. I’m Eyepiece selling because I upgraded to an LX80 mount. Excellent condition. I don’t want to ship this thing so local pickup is necessary. Asking: $180 (cash) Contact: Fred Fry Asking: $400 Email: [email protected] Contact: Glenn R. Cameron Phone: 330-737-1472 Email: [email protected] For Sale: For Sale: Teleview Radian 18 mm Eyepiece 22mm Orion Epic ED-2 ED Eyepiece Excellent condition. 25mm Orion Epic ED-2 ED Eyepiece Asking: $180 (cash) Asking: $35 each or $65 for both Contact: Fred Fry Contact: Glenn Cameron Email: [email protected] Phone: 330-737-1472 Email: [email protected] Advertize in the Swap n Shop! Send a picture of your item and relevant information to the newsletter editor: [email protected] 4 President’s Column Con’t a six sided figure that has six well neighbors. For northern hemisphere known stars at its vertices. Rigel (beta observers between latitudes 30 and 73 4) Orion’s Club. Stretching northward Orionis), Aldebaran (alpha Tauri), degrees, it is the closest star (after the from Betelgeuse are the stars that Capella (alpha Aurigae), Pollux (beta Sun) that can be seen with the unaided comprise Orion’s Club. Mu Orionis Geminorum), Procyon (alpha Canis eye. marks the elbow, Nu and Xi mark the Minoris),and Sirius (alpha Canis handle of the club and Chi-1 and Chi- Majoris). The asterism connects the Procyon is another prominent star 2 mark the end of the club. six brightest stars in six prominent in the winter sky that is both very 5) Orion’s Shield. West from winter constellations. It provides an bright and very close. It is the eighth Bellatrix lie six stars that are all astronomical version of “connect the brightest star in the sky with an designated Pi Orionis (pi-1, pi-2, pi-3, dots (stars)” and provides a useful apparent magnitude of 0.34. It is pi-4, pi-5, and pi-6) that make up the means to locate each of the individual 11.46 light years distant. Procyon’s shield of Orion. stars and constellations and their brightness is more due to its closeness 6) Orion’s Sword. Hanging southward relative positions in the winter sky. and not so much due to an intrinsic from Orion’s belt is his sword. It brightness. Procyon is 1.4 times the consists of the Trapezium and the In more recent years I have noticed mass, twice the radius, and 6.9 times Great Orion Nebula (M42). Using a trend of folks asking, “What is the more luminous than the Sun. binoculars M42 demonstrates clouds distance of this star?” or the distance of nascent stars, luminous gas, and to other astronomical objects. The These are but a few of the dust. winter sky prominently displays two highlights of our January night sky. of the brightest and closest stars in the Our celestial canopy holds treasures The Trapezium is a young tight entire sky.
Load more

Recommended publications
  • Standing on the Shoulders of Giants: New Mass and Distance Estimates
    Draft version October 15, 2020 Typeset using LATEX twocolumn style in AASTeX63 Standing on the shoulders of giants: New mass and distance estimates for Betelgeuse through combined evolutionary, asteroseismic, and hydrodynamical simulations with MESA Meridith Joyce,1, 2 Shing-Chi Leung,3 Laszl´ o´ Molnar,´ 4, 5, 6 Michael Ireland,1 Chiaki Kobayashi,7, 8, 2 and Ken'ichi Nomoto8 1Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia 2ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australia 3TAPIR, Walter Burke Institute for Theoretical Physics, Mailcode 350-17, Caltech, Pasadena, CA 91125, USA 4Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Konkoly-Thege ´ut15-17, H-1121 Budapest, Hungary 5MTA CSFK Lendulet¨ Near-Field Cosmology Research Group, Konkoly-Thege ´ut15-17, H-1121 Budapest, Hungary 6ELTE E¨otv¨os Lor´and University, Institute of Physics, Budapest, 1117, P´azm´any P´eter s´et´any 1/A 7Centre for Astrophysics Research, Department of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK 8Kavli Institute for the Physics and Mathematics of the Universe (WPI),The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Kashiwa, Chiba 277-8583, Japan (Dated: Accepted XXX. Received YYY; in original form ZZZ) ABSTRACT We conduct a rigorous examination of the nearby red supergiant Betelgeuse by drawing on the synthesis of new observational data and three different modeling techniques. Our observational results include the release of new, processed photometric measurements collected with the space-based SMEI instrument prior to Betelgeuse's recent, unprecedented dimming event.
    [Show full text]
  • Thanet Astronomy Group Astronomy for Everyone in Plain English
    Thanet Astronomy Group Astronomy for Everyone in Plain English What to see December 29th Constellation (Orion) Stars (Betelguese, Bellatrix, Alnitak, Alnilam, Mintaka, Rigel, Saiph,) Asterism (The Winter Triangle) Stars (Betelguese, Sirius, Procyon) November to March the constellation Orion the Hunter is at its best. There are some 20 prominent stars in this constellation. The brightest and more easily observed stars are the 8 in the main body. The other stars form Orion's right arm with club, and a slain animal in his left hand. These stars are dimmer and difficult to see due to light pollution. At 8:00pm Looking South East at 119° up to 30° you see the star Betelguese, the top left corner of Orion, a red super giant, more than 1½ billion kms in diameter. Look at 127° up to 33° you see the star Bellatrix, the top right corner of Orion, at 8½ million kms in diameter. Look at 128° down to 24° you see Alnitak, the first of three stars side by side, forming Orion's belt. Alnitak, Alnilam (at 128° 25°) and Mintaka (at 129° 26°). Probably one of the more easily recognised groups of stars in this area of sky. Look at 137° down to 21° you see the star Rigel, the bottom right corner of Orion. A blue/white super giant, 108 million kms in diameter. Look at 130° down to 16° you see the star Saiph the bottom left corner of Orion, nearly 31 million kms in diameter. Orion Stars Orion the Hunter In August I wrote about The Summer Triangle.
    [Show full text]
  • C. Mintaka, Alnitak, Alnilam
    Post-18.1: This graph shows the functional form of the dependence of the parallax angle on the distance an object is from Earth. If the minimum parallax angle we could measure were 0.5 arcsec, what is the maximum distance of a star that we could measure? a. ~ 1.00 arcsec b. ~ 2.2 pc c. ~ 10 pc ©2014 W. W. Norton & Company, Inc. 8 Post-18.1: This graph shows the functional form of the dependence of the parallax angle on the distance an object is from Earth. If the minimum parallax angle we could measure were 0.5 arcsec, what is the maximum distance of a star that we could measure? a. ~ 1.00 arcsec b. ~ 2.2 pc c. ~ 10 pc ©2014 W. W. Norton & Company, Inc. 9 Post-18.2: The Moon never stops in its orbit; however, it is possible to get an exact measurement of its parallax and thus its distance at any given moment. How would we get the parallax shift of the Moon? a. Take simultaneous measurements from two locations. b. Take two measurements at different times from one location. c. Take two measurements from the same location at the same phase of the Moon. ©2014 W. W. Norton & Company, Inc. 10 Post-18.2: The Moon never stops in its orbit; however, it is possible to get an exact measurement of its parallax and thus its distance at any given moment. How would we get the parallax shift of the Moon? a. Take simultaneous measurements from two locations. b. Take two measurements at different times from one location.
    [Show full text]
  • 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.
    [Show full text]
  • The Hypergiants VY Canis Majoris, Eta Carinae, V766 Centauri and The
    Sixteenth Marcel Grossmann Meeting Contribution ID: 967 Type: Talk in the parallel session The hypergiants VY Canis Majoris, Eta Carinae, V766 Centauri and the red supergiants Betelgeuse, Antares and Aldebaran in the 2.5K SGQ AAVSO database Thursday, 8 July 2021 16:35 (7 minutes) I observe variable stars since 1997. The “candidacy” of Mira Ceti as Betlehem Star because close to Jupiter- Saturn triple conjunction of 6-7 b.C. started at Pontifical University of Lateran and continued in Yale (2001- 2004). Maxima correlation function ruled out Mira for having two consecutive bright maxima, but this prop- erty was confirmed in the “oldest” Myra-type: R Leonis, R Hydrae and Chi Cygni, from their almostfour- century-long lightcurves. To a bright maximum normally a dim one follows, as the correlation function of their consecutive maxima shows. These studies were supported by historical and personal visual observations. Since 2011 I observe firstmag- nitude variable stars, with airmass correction to reach 0.01 magnitudes accuracy with naked eye. AAVSO observer Sebastian Otero first claimed this accuracy, as for NovaCentauri 2013, observed by me fromPorto Alegre and Rio de Janeiro. Betelgeuse’s 801 observations in 10 years, include the deep minimum of 2020. My SGQ contributions to AAVSO-database, paralleled with Betelgeuse’s V-band measurements, help to define the “personal equations” present in all 25M visual observations before CCD era (1911-on) going back to 1893 for Betelgeuse. The temporal extension of lightcurves is crucial to understand the stellar behaviour. More complicate cases are Antares and Aldebaran, less variable and with distant comparison stars.
    [Show full text]
  • On Massive Dust Clumps in the Envelope of the Red Supergiant VY Canis Majoris
    Astronomy & Astrophysics manuscript no. VYCMAclumps_CONTI_May2019 c ESO 2019 July 2, 2019 On massive dust clumps in the envelope of the red supergiant VY Canis Majoris ? T. Kaminski´ Center for Astrophysics | Harvard & Smithsonian, Smithsonian Astrophysical Observatory, e-mail: [email protected] Received; accepted ABSTRACT The envelope of the red supergiant VY CMa has long been considered an extreme example of episodic mass loss that is possibly taking place in other cool and massive evolved stars. Recent (sub-)millimeter observations of the envelope revealed the presence of massive dusty clumps within 800 mas from the star which reinforce the picture of drastic mass-loss phenomena in VY CMa. We present new ALMA observations at an angular resolution of 0.100and at an unprecedented sensitivity that reveal further details about the dusty clumps. We resolve more discrete features and identify a submillimeter counterpart of a more distant Clump SW known from visual observations. The brightest clump, named C, is marginally resolved in the observations. Gas seen against the resolved continuum emission of clump C produces a molecular spectrum in absorption, in lines of mainly sulfur-bearing species. Except for SW Clump, no molecular emission is found to be associated with the dusty clumps and we propose that the dusty structures have an atypically low gas content. We attempt to reproduce the properties of the dusty clumps through three-dimensional radiative-transfer modeling. Although a clump configuration explaining the observations is found, it is not unique. A very high optical depth of all clumps to the stellar radiation make the modeling very challenging and requires unrealistically high dust masses for one of them.
    [Show full text]
  • Winter Observing Notes
    Wynyard Planetarium & Observatory Winter Observing Notes Wynyard Planetarium & Observatory PUBLIC OBSERVING – Winter Tour of the Sky with the Naked Eye NGC 457 CASSIOPEIA eta Cas Look for Notice how the constellations 5 the ‘W’ swing around Polaris during shape the night Is Dubhe yellowish compared 2 Polaris to Merak? Dubhe 3 Merak URSA MINOR Kochab 1 Is Kochab orange Pherkad compared to Polaris? THE PLOUGH 4 Mizar Alcor Figure 1: Sketch of the northern sky in winter. North 1. On leaving the planetarium, turn around and look northwards over the roof of the building. To your right is a group of stars like the outline of a saucepan standing up on it’s handle. This is the Plough (also called the Big Dipper) and is part of the constellation Ursa Major, the Great Bear. The top two stars are called the Pointers. 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 to the left, 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 right 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. Check with binoculars. © Rob Peeling, CaDAS, 2007 version 2.0 Wynyard Planetarium & Observatory PUBLIC OBSERVING – Winter Polaris, Kochab and Pherkad mark the constellation Ursa Minor, the Little Bear.
    [Show full text]
  • TAAS Monthly Observing Challenge December 2015 Deep Sky Object
    TAAS Monthly Observing Challenge December 2015 Deep Sky Object NGC 772 (GX) Aries ra: 01h 59m 20.1s dec: +19° 00’ 26” Magnitude (visual) = 10.3 Size = 7.2’ x 4.3’ Position angle = 130° Description: NGC 772 (also known as Arp 78) is an unbarred spiral galaxy approximately 130 million light-years away in the constellation Aries. Around 200,000 light years in diameter, NGC 772 is twice the size of the Milky Way Galaxy, and is surrounded by several satellite galaxies – including the dwarf elliptical, NGC 770 – whose tidal forces on the larger galaxy have likely caused the emergence of a single elongated outer spiral arm that is much more developed than the others arms. Halton Arp includes NGC 772 in his Atlas of Peculiar Galaxies as Arp 78, where it is described as a "Spiral galaxy with a small high-surface brightness companion". Two supernovae (SN 2003 hl & SN 2003 iq) have been observed in NGC 772. Source: https://www.wikipedia.org/wiki/NGC_772 AL: Herschel 400 Challenge Object NGC 2371 / 2372 (PN) Gemini ra: 07h 25m 34.8s dec: +29° 29’ 22” Magnitude (visual) = 11.2 Size = 62” Description: NGC 2371-2 is a dual lobed planetary nebula located in the constellation Gemini. Visually, it appears like it could be two separate objects; therefore, two entries were given to the planetary nebula by William Herschel in the "New General Catalogue", so it may be referred to as NGC 2371, NGC 2372, or variations on this name. Source: https://www.wikipedia.org/wiki/NGC_2371-2 AL: Herschel 400, Planetary Nebula Binocular Object NGC 1807 (OC) Taurus ra: 05h 10m 46.0s dec: +16° 31’ 00” Magnitude (visual) = 7.0 Size = 12’ Description: NGC 1807 is an open cluster at the border of the constellations Taurus and Orion near the open cluster NGC 1817.
    [Show full text]
  • Educator's Guide: Orion
    Legends of the Night Sky Orion Educator’s Guide Grades K - 8 Written By: Dr. Phil Wymer, Ph.D. & Art Klinger Legends of the Night Sky: Orion Educator’s Guide Table of Contents Introduction………………………………………………………………....3 Constellations; General Overview……………………………………..4 Orion…………………………………………………………………………..22 Scorpius……………………………………………………………………….36 Canis Major…………………………………………………………………..45 Canis Minor…………………………………………………………………..52 Lesson Plans………………………………………………………………….56 Coloring Book…………………………………………………………………….….57 Hand Angles……………………………………………………………………….…64 Constellation Research..…………………………………………………….……71 When and Where to View Orion…………………………………….……..…77 Angles For Locating Orion..…………………………………………...……….78 Overhead Projector Punch Out of Orion……………………………………82 Where on Earth is: Thrace, Lemnos, and Crete?.............................83 Appendix………………………………………………………………………86 Copyright©2003, Audio Visual Imagineering, Inc. 2 Legends of the Night Sky: Orion Educator’s Guide Introduction It is our belief that “Legends of the Night sky: Orion” is the best multi-grade (K – 8), multi-disciplinary education package on the market today. It consists of a humorous 24-minute show and educator’s package. The Orion Educator’s Guide is designed for Planetarians, Teachers, and parents. The information is researched, organized, and laid out so that the educator need not spend hours coming up with lesson plans or labs. This has already been accomplished by certified educators. The guide is written to alleviate the fear of space and the night sky (that many elementary and middle school teachers have) when it comes to that section of the science lesson plan. It is an excellent tool that allows the parents to be a part of the learning experience. The guide is devised in such a way that there are plenty of visuals to assist the educator and student in finding the Winter constellations.
    [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]
  • 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.
    [Show full text]
  • Ioptron CEM40 Center-Balanced Equatorial Mount
    iOptron®CEM40 Center-Balanced Equatorial Mount Instruction Manual Product CEM40 (#7400A series) and CEM40EC (#7400ECA series, as shown) Please read the included CEM40 Quick Setup Guide (QSG) BEFORE taking the mount out of the case! This product is a precision instrument. Please read the included QSG before assembling the mount. Please read the entire Instruction Manual before operating the mount. You must hold the mount firmly when disengaging the gear switches. Otherwise personal injury and/or equipment damage may occur. Any worm system damage due to improper operation will not be covered by iOptron’s limited warranty. If you have any questions please contact us at [email protected] WARNING! NEVER USE A TELESCOPE TO LOOK AT THE SUN WITHOUT A PROPER FILTER! Looking at or near the Sun will cause instant and irreversible damage to your eye. Children should always have adult supervision while using a telescope. 2 Table of Contents Table of Contents ........................................................................................................................................ 3 1. CEM40 Introduction ............................................................................................................................... 5 2. CEM40 Overview ................................................................................................................................... 6 2.1. Parts List .........................................................................................................................................
    [Show full text]