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Planet Positions: 1 Planet Positions
Planet Positions: 1 Planet Positions As the planets orbit the Sun, they move around the celestial sphere, staying close to the plane of the ecliptic. As seen from the Earth, the angle between the Sun and a planet -- called the elongation -- constantly changes. We can identify a few special configurations of the planets -- those positions where the elongation is particularly noteworthy. The inferior planets -- those which orbit closer INFERIOR PLANETS to the Sun than Earth does -- have configurations as shown: SC At both superior conjunction (SC) and inferior conjunction (IC), the planet is in line with the Earth and Sun and has an elongation of 0°. At greatest elongation, the planet reaches its IC maximum separation from the Sun, a value GEE GWE dependent on the size of the planet's orbit. At greatest eastern elongation (GEE), the planet lies east of the Sun and trails it across the sky, while at greatest western elongation (GWE), the planet lies west of the Sun, leading it across the sky. Best viewing for inferior planets is generally at greatest elongation, when the planet is as far from SUPERIOR PLANETS the Sun as it can get and thus in the darkest sky possible. C The superior planets -- those orbiting outside of Earth's orbit -- have configurations as shown: A planet at conjunction (C) is lined up with the Sun and has an elongation of 0°, while a planet at opposition (O) lies in the opposite direction from the Sun, at an elongation of 180°. EQ WQ Planets at quadrature have elongations of 90°. -
Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur
Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur To cite this version: Alex Soumbatov-Gur. Phobos, Deimos: Formation and Evolution. [Research Report] Karpov institute of physical chemistry. 2019. hal-02147461 HAL Id: hal-02147461 https://hal.archives-ouvertes.fr/hal-02147461 Submitted on 4 Jun 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur The moons are confirmed to be ejected parts of Mars’ crust. After explosive throwing out as cone-like rocks they plastically evolved with density decays and materials transformations. Their expansion evolutions were accompanied by global ruptures and small scale rock ejections with concurrent crater formations. The scenario reconciles orbital and physical parameters of the moons. It coherently explains dozens of their properties including spectra, appearances, size differences, crater locations, fracture symmetries, orbits, evolution trends, geologic activity, Phobos’ grooves, mechanism of their origin, etc. The ejective approach is also discussed in the context of observational data on near-Earth asteroids, main belt asteroids Steins, Vesta, and Mars. The approach incorporates known fission mechanism of formation of miniature asteroids, logically accounts for its outliers, and naturally explains formations of small celestial bodies of various sizes. -
5 the Orbit of Mercury
Name: Date: 5 The Orbit of Mercury Of the five planets known since ancient times (Mercury, Venus, Mars, Jupiter, and Saturn), Mercury is the most difficult to see. In fact, of the 6 billion people on the planet Earth it is likely that fewer than 1,000,000 (0.0002%) have knowingly seen the planet Mercury. The reason for this is that Mercury orbits very close to the Sun, about one third of the Earth’s average distance. Therefore it is always located very near the Sun, and can only be seen for short intervals soon after sunset, or just before sunrise. It is a testament to how carefully the ancient peoples watched the sky that Mercury was known at least as far back as 3,000 BC. In Roman mythology Mercury was a son of Jupiter, and was the god of trade and commerce. He was also the messenger of the gods, being “fleet of foot”, and commonly depicted as having winged sandals. Why this god was associated with the planet Mercury is obvious: Mercury moves very quickly in its orbit around the Sun, and is only visible for a very short time during each orbit. In fact, Mercury has the shortest orbital period (“year”) of any of the planets. You will determine Mercury’s orbital period in this lab. [Note: it is very helpful for this lab exercise to review Lab #1, section 1.5.] Goals: to learn about planetary orbits • Materials: a protractor, a straight edge, a pencil and calculator • Mercury and Venus are called “inferior” planets because their orbits are interior to that of the Earth. -
Proper Motion Analysis of the Jet of R Aquarii
A&A 424, 157–164 (2004) Astronomy DOI: 10.1051/0004-6361:20035866 & c ESO 2004 Astrophysics Proper motion analysis of the jet of R Aquarii K. Mäkinen1,H.J.Lehto1,2,R.Vainio3, and D. R. H. Johnson4 1 Tuorla Observatory, Väisäläntie 20, 21500 Piikkiö, Finland e-mail: [email protected] 2 Department of Physics, 20014 Turku University, Finland 3 Department of Physical Sciences, PO Box 64, 00014 University of Helsinki, Finland 4 Charterhouse, Godalming, Surrey, GU7 2DX, UK Received 15 December 2003 / Accepted 18 May 2004 Abstract. We have observed the jet of R Aquarii at high resolution with the VLA in 1992.83 and in 1999.78. Observations in the first epoch have resolved the base of the jet which shows a helical structure. We cannot detect the expected new jet component at either epoch. This does not disprove the idea of periodic ejection. Either the timing inferred from the acceleration models, or the assumed periastron passage is incorrect. Alternatively, a single new component cannot be resolved due to the dense core. Proper motion analysis of the jet components shows that previously derived acceleration models do not fit our new data. Indeed, the first ∼1 of the jet, both to north-east and south-west, appears fixed and has slowly moving shocks at the termination points, whereas the positions of the outer components fit best a ballistic orbit. We propose that the components are formed due to enhanced matter flow at periastron, accelerated during the first 1 and then ejected as bullets. Component A at a distance of ∼4 from the core has broken into two parts, similar to what was previously assumed to have happened to the outermost components B and D. -
Field Astronomy Circumpolar Star at Elongation ➢ at Elongation a Circumpolar Star Is at the Farthest Position from the Pole Either in the East Or West
Field Astronomy Circumpolar Star at Elongation ➢ At elongation a circumpolar star is at the farthest position from the pole either in the east or west. ➢ When the star is at elongation (East or West), which is perpendicular to the N-S line. ➢ Thus the ZMP is 90° as shown in the figure below. Distances between two points on the Earth’s surface ➢ Direct distance From the fig. above, in the spherical triangle APB P = Difference between longitudes of A and B BP = a = co-latitude of B = 90 – latitude of B AP = b = co-latitude of A = 90 – latitude of A Apply the cosine rule: cosp− cos a cos b CosP = sinab sin Find the value of p = AB Then the distance AB = arc length AB = ‘p’ in radians × radius of the earth ➢ Distance between two points on a parallel of latitude Let A and B be the two points on the parallel latitude θ. Let A’ and B’ be the corresponding points on the equator having the same longitudes (ФB, ФA). Thus from the ∆ O’AB AB = O’B(ФB - ФA) From the ∆ O’BO o O’B = OB’ sin (90- θ) Since =BOO ' 90 = R cos θ where R=Radius of the Earth. AB= (ФB - ФA) R cos θ where ФB , ФA are longitudes of B and A in radians. Practice Problems 1. Find the shortest distance between two places A and B on the earth for the data given below: Latitude of A = 14° N Longitude of A = 60°30‘E Latitude of B = 12° N Longitude of A = 65° E Find also direction of B from A. -
Observing Project
Observing Project Objectives: • Learn how to “practically” measure angles on the sky • How to take data and assess measurement errors • How to plot and interpret graphs • Geometry of Earth-Moon-Sun system • Measure the orbital period of the Moon • Predict the phase of the moon of a future date th • First 3 Observations Due May 29 !!!! Moon Moves Across the Constellations Could measure the movement against the background stars The Moon moves at an angle (difficult to measure) The stars themselves move over days due to our revolution around the Sun Measure with respect to the sun! Moon’s Elongation: Separation of the Moon and Sun in the sky. Moon’s Elongation Angle Moon’s Orbit • Fix the Moon-Sun geometry • Elongation angle changes as the Moon orbits • So do the Moon phases 315° 225° 270° Moon Phase Number TPS At what Elongation angle is the Moon visible during the day? 315° A. 100 B. 45 225° C. 180 270° D. 225 TPS What Moon phase could you directly measure the Moon’s Elongation Angle? 315° A. Waxing Gibbous 225° B. Waxing Crescent 270° C. Full Moon D. Depends on the time of year *Don’t Look Directly into the SUN!!! • How do we measure the Moon’s elongation angle at night??? • Hour Angle: angle of object from your local Meridian • What is the time of day of the “little cowboy”? • A: Midnight Meridian • How do we measure the Sun’s HA at night??? • Our clocks are based of the Sun’s Position. • Noon: when the Sun crosses our Meridian • What is the HA of the Sun at Midnight? • A: 180 degrees Meridian Moon Elongation = Sun HA – Moon HA Daylight Savings Time Artificially move the clocks forward by 1 hour How does this change Astronomical Noon??? Would this affect your measurement??? Mountain Standard Time (MST) • The Sun is closer to the Meridian Mountain Daylight Time (MDT) MST = MDT – 1 hour Hours to Degrees Earth rotates once every 24 hours • 360 degrees per 24 hours • 360/24 = 15 (degrees/hour) Sun’s HA (degrees) = [ MST – 12 (noon) ] * 15 What is the HA of a first quarter Moon at midnight? A. -
August 2017 BRAS Newsletter
August 2017 Issue Next Meeting: Monday, August 14th at 7PM at HRPO nd (2 Mondays, Highland Road Park Observatory) Presenters: Chris Desselles, Merrill Hess, and Ben Toman will share tips, tricks and insights regarding the upcoming Solar Eclipse. What's In This Issue? President’s Message Secretary's Summary Outreach Report - FAE Light Pollution Committee Report Recent Forum Entries 20/20 Vision Campaign Messages from the HRPO Perseid Meteor Shower Partial Solar Eclipse Observing Notes – Lyra, the Lyre & Mythology Like this newsletter? See past issues back to 2009 at http://brastro.org/newsletters.html Newsletter of the Baton Rouge Astronomical Society August 2017 President’s Message August, 21, 2017. Total eclipse of the Sun. What more can I say. If you have not made plans for a road trip, you can help out at HRPO. All who are going on a road trip be prepared to share pictures and experiences at the September meeting. BRAS has lost another member, Bart Bennett, who joined BRAS after Chris Desselles gave a talk on Astrophotography to the Cajun Clickers Computer Club (CCCC) in January of 2016, Bart became the President of CCCC at the same time I became president of BRAS. The Clickers are shocked at his sudden death via heart attack. Both organizations will miss Bart. His obituary is posted online here: http://www.rabenhorst.com/obituary/sidney-barton-bart-bennett/ Last month’s meeting, at LIGO, was a success, even though there was not much solar viewing for the public due to clouds and rain for most of the afternoon. BRAS had a table inside the museum building, where Ben and Craig used material from the Night Sky Network for the public outreach. -
GEORGE HERBIG and Early Stellar Evolution
GEORGE HERBIG and Early Stellar Evolution Bo Reipurth Institute for Astronomy Special Publications No. 1 George Herbig in 1960 —————————————————————– GEORGE HERBIG and Early Stellar Evolution —————————————————————– Bo Reipurth Institute for Astronomy University of Hawaii at Manoa 640 North Aohoku Place Hilo, HI 96720 USA . Dedicated to Hannelore Herbig c 2016 by Bo Reipurth Version 1.0 – April 19, 2016 Cover Image: The HH 24 complex in the Lynds 1630 cloud in Orion was discov- ered by Herbig and Kuhi in 1963. This near-infrared HST image shows several collimated Herbig-Haro jets emanating from an embedded multiple system of T Tauri stars. Courtesy Space Telescope Science Institute. This book can be referenced as follows: Reipurth, B. 2016, http://ifa.hawaii.edu/SP1 i FOREWORD I first learned about George Herbig’s work when I was a teenager. I grew up in Denmark in the 1950s, a time when Europe was healing the wounds after the ravages of the Second World War. Already at the age of 7 I had fallen in love with astronomy, but information was very hard to come by in those days, so I scraped together what I could, mainly relying on the local library. At some point I was introduced to the magazine Sky and Telescope, and soon invested my pocket money in a subscription. Every month I would sit at our dining room table with a dictionary and work my way through the latest issue. In one issue I read about Herbig-Haro objects, and I was completely mesmerized that these objects could be signposts of the formation of stars, and I dreamt about some day being able to contribute to this field of study. -
Astronomy Lab: Planets
Phys 102 Astronomy Name ____________________Key POSITIONS OF THE PLANETS PLANETARY POSITIONS WITH RESPECT TO THE SUN: 23 Use appendix 11 in the Field Guide for February 1, 2021 to complete the following table: Object Planetary Longitude Atlas Chart # Constellation Elongation Sol () 313 32 Capricornus ZERO! Planets ☿ in order Mercury ( ) 326 32 Capricornus 13° E of orbit Venus(♀) 300 43 Capricornus 13° W distance from the Mars (♂) 43 22 Aries 90° E Sun. Jupiter (♃) 310 31/43 Capricornus 3° W Saturn (♄) 305 31/43 Capricornus 8° W PLANETARY POSITIONS IN THE SKY The digram below shows an observer looking south at sunset. From the planetary longitude of the sun and planets abovee, show where the planets will be in the observer’s sky (some may be below the horizon). Discuss how these positions correspond to the times the planets will be visible to this observer (eg. after sunset, before sunrise or most of the night). 11 Sun’s PL + 90° _______43° ♂ At E. Quadrature! Observer’s meridian Come look for the planets with me! ☿ Sun’s PL ± 180 Sun’s PL _______133° _______ E observer W ♃ 313° Sun setting on looking ♄ western horizon south ♀ Sun’s PL - 90°: _______223° Phys. 102: Astronomy Spring 2021 PLANETARY POSITIONS IN THE SOLAR SYSTEM A view of the solar system as seen FROM ABOVE THE NORTH ECLIPTIC POLE with the sun in the center is shown below. The line from the Earth ( ) to the Sun ( ) represents the planetary longitude of the sun. For each of the five visible planets, 1) Center a protractor on the Earth, measure the elongation angle from the sun's longitude. -
Ultraviolet Temporal Variability of the Peculiar Star R Aquarii S
Chapman University Chapman University Digital Commons Mathematics, Physics, and Computer Science Science and Technology Faculty Articles and Faculty Articles and Research Research 1995 Ultraviolet Temporal Variability of the Peculiar Star R Aquarii S. R. Meier USN, Research Laboratory Menas Kafatos Chapman University, [email protected] Follow this and additional works at: http://digitalcommons.chapman.edu/scs_articles Part of the Instrumentation Commons, and the Stars, Interstellar Medium and the Galaxy Commons Recommended Citation Meier, S.R., Kafatos, M. (1995) Ultraviolet Temporal Variability of the Peculiar Star R Aquarii, Astrophysical Journal, 451: 359-371. doi: 10.1086/176225 This Article is brought to you for free and open access by the Science and Technology Faculty Articles and Research at Chapman University Digital Commons. It has been accepted for inclusion in Mathematics, Physics, and Computer Science Faculty Articles and Research by an authorized administrator of Chapman University Digital Commons. For more information, please contact [email protected]. Ultraviolet Temporal Variability of the Peculiar Star R Aquarii Comments This article was originally published in Astrophysical Journal, volume 451, in 1995. DOI: 10.1086/176225 Copyright IOP Publishing This article is available at Chapman University Digital Commons: http://digitalcommons.chapman.edu/scs_articles/139 THE AsTROPHYSICAL JOURNAL, 451:359-371, 1995 September 20 © 1995. The American Astronomical Society. All rights reserved. Printed in U.S.A. 1995ApJ...451..359M -
ASTR 1010 Homework Solutions
ASTR 1010 Homework Solutions Chapter 1 24. Set up a proportion, but be sure that you express all the distances in the same units (e.g., centimeters). The diameter of the Sun is to the size of a basketball as the distance to Proxima Centauri (4.2 LY) is to the unknown distance (X), so (1.4 × 1011 cm) / (30 cm) = (4.2 LY)(9.46 × 1017 cm/LY) / (X) Rearranging terms, we get X = (4.2 LY)(9.46 × 1017 cm/LY)(30 cm) / (1.4 × 1011 cm) = 8.51 × 108 cm = 8.51 × 103 km = 8510 km In other words, if the Sun were the size of a 30-cm diameter ball, the nearest star would be 8510 km away, which is roughly the distance from Los Angeles to Tokyo. 27. The Sun’s hydrogen mass is (3/4) × (1.99 × 1030 kg) = 1.49 × 1030 kg. Now divide the Sun’s hydrogen mass by the mass of one hydrogen atom to get the number of hydrogen atoms contained in the Sun: (1.49 × 1030 kg) / (1.67 × 10-27 kg/atom) = 8.92 × 1056 atoms. 8 11 29. The distance from the Sun to the Earth is 1 AU = 1.496 × 10 km = 1.496 × 10 m. The light-travel time is the distance, 1 AU, divided by the speed of light, i.e., 11 8 3 time = distance/speed = (1.496 × 10 m) / (3.00 × 10 m/s) = 0.499 × 10 s = 499 s = 8.3 minutes. 34. Since you are given diameter (D = 2.6 cm) and angle, and asked to find distance, you need to rewrite the small-angle formula as d = (206,265)(D) / (α). -
A Astronomical Terminology
A Astronomical Terminology A:1 Introduction When we discover a new type of astronomical entity on an optical image of the sky or in a radio-astronomical record, we refer to it as a new object. It need not be a star. It might be a galaxy, a planet, or perhaps a cloud of interstellar matter. The word “object” is convenient because it allows us to discuss the entity before its true character is established. Astronomy seeks to provide an accurate description of all natural objects beyond the Earth’s atmosphere. From time to time the brightness of an object may change, or its color might become altered, or else it might go through some other kind of transition. We then talk about the occurrence of an event. Astrophysics attempts to explain the sequence of events that mark the evolution of astronomical objects. A great variety of different objects populate the Universe. Three of these concern us most immediately in everyday life: the Sun that lights our atmosphere during the day and establishes the moderate temperatures needed for the existence of life, the Earth that forms our habitat, and the Moon that occasionally lights the night sky. Fainter, but far more numerous, are the stars that we can only see after the Sun has set. The objects nearest to us in space comprise the Solar System. They form a grav- itationally bound group orbiting a common center of mass. The Sun is the one star that we can study in great detail and at close range. Ultimately it may reveal pre- cisely what nuclear processes take place in its center and just how a star derives its energy.