• Study Resource
  • Explore Categories
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
Solutions
Solutions

... 41) All Plutinos have a 3:2 orbital resonance with Neptune. Most Plutinos at closest approach to the sun are closer to the sun than Neptune is from the sun. Why is this a stable orbit? a) it isn’t b) the expected collisional time with Neptune is 200 billion years c) when Plutinos get to their close ...
Test and answer key  - Solar Physics and Space Weather
Test and answer key - Solar Physics and Space Weather

... C *can be tested by observation. D need not have a connection with physical reality. 3. One arcsecond is equal to A *1/3600 degree. B 1/60 of a full circle. C 1/60 degree D 1/3600 of a full circle. 4. The Moon's angular diameter in our sky is measured to be half a degree. From this, we can find the ...
Solo - Net Start Class
Solo - Net Start Class

... Hipparchus: Seven hundred and seventy two, Seven hundred and seventy three… Seven hundred and seventy four… Carl Sagan: Hey Hipparchus! What are you counting? Hipparchus: Stars. What else? Seven hundred and seventy four… Oh! Did I already say that? Sagan: I don’t know. Hipparchus: Argh!! One, two, t ...
Protostar formation
Protostar formation

... A star mass determines which fusion reaction are possible in the core, and hence its luminosity, surface temperature and lifetime. Object with mass smaller than 8% of the solar mass (75 times Jupiter mass) never ignite fusion, and therefore fade to obscurity in about 100 million years. These are Bro ...
Stargazing in ancient Egypt
Stargazing in ancient Egypt

... Sun’s position. It usually ends in a point. Occasionally, a pillar will appear both above and below the Sun simultaneously. Sun pillars arise from sunlight reflecting off the surfaces of sixsided, plate-like ice crystals that make up thin, high-level clouds in Earth’s atmosphere. Although they requi ...
HERE - Gallopade International
HERE - Gallopade International

... The sun and the objects around it are called a “solar system” because the objects move around the sun in organized patterns. Every object travels around the sun on its own separate path, called an orbit. Scientists predict the future movement of planets, moons, and other space objects by studying th ...
Lecture #33: Solar System Origin I The Main Point What is a
Lecture #33: Solar System Origin I The Main Point What is a

... Astro 102/104 The ...
VARIOUS MEASUREMENTS OF TIME
VARIOUS MEASUREMENTS OF TIME

... successive upper transits of the first point of Aries (Y). It begins at the instant when the first point of Aries records 0h, 0m, 0s. At any other instant, the sidereal time will be the hour angle of Y reckoned westward from 0h to 24h. The sidereal day is divided into 24 hours, each hour subdivided ...
Chapter 13 32)Which method could detect a planet in an orbit that is
Chapter 13 32)Which method could detect a planet in an orbit that is

... 32)Which method could detect a planet in an orbit that is face-on to the Earth? c) Astrometric method. The astrometric method measures the tangential motion of a star, and a face-on planetary orbit would force the star to move in the tangential direction. In contrast, both the Doppler and transit me ...
the Scientific Revolution - Kapteyn Astronomical Institute
the Scientific Revolution - Kapteyn Astronomical Institute

... 5.  Whatever motion appears in the firmament arises not from any motion of the  firmament, but from the earth's motion. The earth together with its circumjacent  elements performs a complete rotation on its fixed poles in a daily motion, while  the firmament and highest heaven abide unchanged. 6.  W ...
Stellar Aspirations
Stellar Aspirations

... the Ulysse Nardin Tellurium Johannes Kepler, ...
Sizing Up The Universe
Sizing Up The Universe

... have a recessional velocity of 710 kilometers per second, and one that is 100 megaparsecs away from us will have a recessional velocity of 7,100 kilometers per second. The galaxies are moving apart as the universe expands. Trace all those galaxies backward in time, and they all come together about 1 ...
sc_examII_fall_2002 - University of Maryland
sc_examII_fall_2002 - University of Maryland

... 26. a) Describe and account for the physical changes that we see from Earth as a comet approaches the Sun. (3 pts.) b) Asteroids have been photographed by spacecraft. Describe what one looks like. (2 pts.) ...
8. The Sun as a Star
8. The Sun as a Star

... but only because it's so massive. Of course, the Sun produces energy by nuclear reactions, while I produce energy by chemical reactions. That's why the Sun can go on shining for ten billion years, whereas I get hungry every few hours. The enormous lifetime of the Sun gives us another perspective on ...
HR 6060: The Closest Ever Solar Twin
HR 6060: The Closest Ever Solar Twin

... next best solar twins, the 16 Cyg A and B pair, have Fe lines 3% stronger than in the Sun (figures 6a,b) according to the data of Friel et al. (1993). The data of Hardorp (1982) at 20 Å resolution, in the 3640-4100 wavelength range, imply HR 6060 and 16 Cyg A to be weaker-lined than the Sun, 16 Cyg ...
Test #3
Test #3

... a. the Earth would spiral inward b. the Earth would jump to a smaller orbit c. the size of the Earth's orbit would increase rapidly d. the Earth's orbit would remain the same 2. A neutron star is expected to spin rapidly because a. they conserved angular momentum when they collapsed. b. they have hi ...
Slide 1
Slide 1

... just mean that the farther you get from the equator, the colder it gets? No, because that tilt changes which way it faces depending on the season. In summer, we here in the US follow the path of the dotted line over the course of a day. You can see that this gets us pretty close to the direct-sunlig ...
stars
stars

... • Stars change over their lifespan just like animals change throughout their life. • Nebula-a large cloud of gas and dust spread out over a large volume of space. • They can have different appearances bright or dark ...
lecture_5_mbu
lecture_5_mbu

... Where the particle number density n is related to the mass density , and chemical composition  (the mean molecular weight), by ...
Nicolaus Copernicus – 500 years of experimental science
Nicolaus Copernicus – 500 years of experimental science

... Sailors in Copernicus times were on regular basis watching the height of the Sun or a given star for navigation purposes ...
Our Sun - STEMpire Central
Our Sun - STEMpire Central

... 4. These stars appear to blink with X rays on and off very rapidly (many times a second), like a lighthouse. a) Cepheid Variables b) RR Lyrae Varibles c) Red Giants d) Pulsars 5. The correct order for spectral classification is: A) LMFAOJK B) OMGROFL C) OBAMKGF D) OBAFGKM 6. More massive stars can ...
lecture_5_mbu_b
lecture_5_mbu_b

... Where the particle number density n is related to the mass density , and chemical composition  (the mean molecular weight), by ...
Light of the Sun - Beck-Shop
Light of the Sun - Beck-Shop

... for a very long time, no one knew exactly how big it was. We now know that this distance is 150 million kilometers, but it took a long time to find that out. By the end of the seventeenth century, astronomers and other scientists had a good understanding of how the planets move around the Sun, but th ...
Lecture 5
Lecture 5

... Where the particle number density n is related to the mass density , and chemical composition  (the mean molecular weight), by ...
29.1 Directed Reading Guide
29.1 Directed Reading Guide

... _____ 55. What is the size of the sun’s core? a. 25% of 1,390 km b. 25% of 13,900 km c. 25% of 139,000 km d. 25% of 1,390,000 km 56. What is the sun’s core made up of? _______________________________________________________________ 57. How does the mass of the sun compare with the mass of Earth? ___ ...
< 1 ... 77 78 79 80 81 82 83 84 85 ... 228 >

Tropical year

A tropical year (also known as a solar year), for general purposes, is the time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox, or from summer solstice to summer solstice. Because of the precession of the equinoxes, the seasonal cycle does not remain exactly synchronized with the position of the Earth in its orbit around the Sun. As a consequence, the tropical year is about 20 minutes shorter than the time it takes Earth to complete one full orbit around the Sun as measured with respect to the fixed stars (the sidereal year).Since antiquity, astronomers have progressively refined the definition of the tropical year. The Astronomical Almanac Online Glossary 2015 states:year, tropical:the period of time for the ecliptic longitude of the Sun to increase 360 degrees. Since the Sun's ecliptic longitude is measured with respect to the equinox, the tropical year comprises a complete cycle of seasons, and its length is approximated in the long term by the civil (Gregorian) calendar. The mean tropical year is approximately 365 days, 5 hours, 48 minutes, 45 seconds.An equivalent, more descriptive, definition is ""The natural basis for computing passing tropical years is the mean longitude of the Sun reckoned from the precessionally moving equinox (the dynamical equinox or equinox of date). Whenever the longitude reaches a multiple of 360 degrees the mean Sun crosses the vernal equinox and a new tropical year begins"". (Borkowski 1991, p. 122)The mean tropical year on January 1, 2000, was about 365.2421897 ephemeris days according to the calculation of Laskar (1986); each ephemeris day lasting 86,400 SI seconds. By 2010 this had decreased to 365.2421891 (365 ephemeris days, 5 hours, 48 minutes and 45.14 seconds). This is about 365.242181 mean solar days, though the length of a mean solar day is constantly changing.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report