The International Astronomical Union at its XVIth General Assembly in Grenoble in 1976, accepted (Resolution No. 1) a whole new consistent set of astronomical constants recommended for reduction of astronomical observations, and for computation of ephemerides. It superseded the IAU's previous recommendations of 1964 (see ), became in effect in the Astronomical Almanac from 1984 onward, and remained in use until the introduction of the . In 1994 the IAU recognized that the parameters became outdated, but retained the 1976 set for sake of continuity, but also recommended to start maintaining a set of "current best estimates". this "sub group for numerical standards" had published a list, which included new constants (like those for relativistic time scales). The system of constants was prepared by Commission 4 on ephemerides led by P. Kenneth Seidelmann (after whom asteroid 3217 Seidelmann is named). At the time, a new standard epoch (J2000.0) was accepted; followed later by a new reference system with fundamental catalogue (FK5), and expressions for precession of the equinoxes,and in 1979 by new expressions for the relation between Universal Time and sidereal time, and in 1979 and 1980 by a theory of nutation. There were no reliable rotation elements for most planets, but a joint working group on Cartographic Coordinates and Rotational Elements was installed to compile recommended values. (Wikipedia).
Parsecs, astronomical units and light years, distance units explained: fizzics.org
Notes to support this video lesson are here: https://www.fizzics.org/measuring-distance-in-astronomy/ Astronomical units , the parsec and the light year are different units commonly used to measure distances in astronomy. Where they come from and how they relate to our basic units of measu
From playlist Astronomy - physics of measuring distance
Units of MASS in Astronomy ✷ Solar Masses ✷ Jupiter Masses ✷ Earth Masses
Our Socratica Astronomy series is back! Bookmark the playlist here: ✷ https://socratica.link/Astro_Playlist We also ask you join our STELLAR email list so we can notify you when new videos go live: ✷ https://snu.socratica.com/astronomy (Don’t rely on the YT algorithm to show you what
From playlist Astronomy
PARSECS, Light Years, or AU? (Astronomy)
Our Socratica Astronomy series is back! Bookmark the playlist here: ✷ https://socratica.link/Astro_Playlist We also ask you join our STELLAR email list so we can notify you when new videos go live: ✷ https://snu.socratica.com/astronomy (Don’t rely on the YT algorithm to show you what
From playlist Astronomy
If you like moons as much as we do, you'll love the SciShow Space moon-themed calendar! Capture yours today at https://www.complexlycalendars.com/products/scishowspace You're familiar with the Moon, but it's not only our moon, depending on your point of view. Hosted by: Hank Green (he/hi
From playlist SciShow Space
Astrophysics: Binary Star System (16 of 40) Elliptical Orbits: A Closer Look
Visit http://ilectureonline.com for more math and science lectures! In this video I will derive the 2 general equation for calculating the eccentricity of a planet around a sun. Next video in this series can be found at: https://youtu.be/2okz-VGkeAI
From playlist ASTROPHYSICS 1 BINARY SYSTEMS & KEPLER'S LAWS
Teach Astronomy - Astronomy Units
http://www.teachastronomy.com/ Astronomers use the metric system, but they also use units that are more appropriate to the huge scales of the universe that are encountered in astronomy. In particular they use three different scales of distance. The astronomical unit, the mean distance be
From playlist 01. Fundamentals of Science and Astronomy
Equilibrium and stability of differentially rotating stellar systems
https://www.sns.ias.edu/stellar-dynamics-workshop/schedule More videos on http://video.ias.edu
From playlist Natural Sciences
Planet X, Pluto, and NASA New Horizons
Enjoy 10% off 6” and 8.5” MOVA Globes with code THEHISTORYGUY. Shop now at https://bit.ly/TheHistoryGuyMOVAGlobes Even as the IAU was officially demoting Pluto, NASA was sending the first probe intended to study it. The history of our surprisingly fond relationship with what was originall
From playlist Space
In this short video explainer, Universe Today publisher Fraser Cain investigates the various ways objects in space get their names. Can you really pay some money and get a star named after you? What objects can you name? http://www.universetoday.com/104134/can-you-really-name-a-star/ ----
From playlist Guide to Space
Since the dawn of recorded history humankind has tried to classify and study the stars. It’s a continuing mission, and astronomers are finding new stars all the time. But how do they get their names? Learn more at HowStuffWorks.com: http://science.howstuffworks.com/star.htm Share on Face
From playlist How Lauren Vogelbaum Works
Teach Astronomy - Astronomical Units
http://www.teachastronomy.com/ The astronomical unit is defined as the mean distance between the Earth and the Sun. It has to be defined as the mean because the orbit is elliptical by a couple of percent. The astronomical unit is 150 million kilometers or 98 million miles. This sets the
From playlist 11. Interplanetary Bodies
Weird Names Around the Solar System
Not all of the objects in the solar system are named after Greek and Roman gods -- some are named after literary figures, movie stars, and don’t get us started on what people think Earth is really called. Hosted by: Reid Reimers ---------- Dooblydoo thanks to the following Patreon suppor
From playlist Space Dose - SciShow Space
Missing Mars Lander Found! - The Countdown #20
SUBSCRIBE, future astronauts: http://goo.gl/bRbj4 THE TOP 5 are listed BELOW!! CLICK HERE to learn more about the Top 5: http://goo.gl/P5utl --------------- THE TOP 5: Star Factory Five New Exoplanets Saturn's Ring Rain Planet Naming Controversy Missing Mars Lander Found --------------
From playlist The Countdown
Weekly Space Hangout - Aug. 16, 2013: Area 51, Hyperloop, Space Fence, Magnetar, New Nova
Like your space news, but you just can't handle reading any more? Then watch our Weekly Space Hangout, where we give you a rundown of all the big space news stories that broke this week. Host: Fraser Cain Panel: Brian Koberlein, David Dickinson, Nancy Atkinson, Nicole Gugliucci Stories:
From playlist Weekly Space Hangout
Solution to Problem #63 Orbital Period
Orbital Period of Binary Star System
From playlist Solutions to Bi-weekly Physics Problems
The ESA is working on a 'fresh-squeezed' spacecraft that will explore Jupiter's moons, and the New Horizons team makes a case for Pluto (and many others)! ---------- Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow ---------- Dooblydoo thanks go to the foll
From playlist SciShow Space
Why Pluto went from Planet to Dwarf Planet
Why has Pluto has gone from being a planet to a dwarf planet? This video explains why as well as the definition of planets and dwarf planets, a includes details about the dwarf planets in our solar system. The change came about when in 2005 Eris, an object with similar dimensions but aroun
From playlist Currently Popular
Astronomy - Ch. 26: Hubble Law (2 of 20) What is The Hubble Constant? H0
Visit http://ilectureonline.com for more math and science lectures! To donate: http://www.ilectureonline.com/donate https://www.patreon.com/user?u=3236071 We will learn that the Hubble Constant is determined by the slop of the observed graph of the Cepheid variables. Next video in this
From playlist ASTRONOMY 26 HUBBLE LAW
Astronomy - Ch. 26: Hubble Law (10 of 20) The Hubble Constant Over the Years
Visit http://ilectureonline.com for more math and science lectures! To donate: http://www.ilectureonline.com/donate https://www.patreon.com/user?u=3236071 We will learn how the Hubble Constant have change over the years since the 1930s to today. Next video in this series can be seen at:
From playlist ASTRONOMY 26 HUBBLE LAW
Why are Astronomers So Bad at Naming Things?
With star names like 2MASS J05551028+0724255, it might seem like astronomers are not so great at naming things. But if you know the code, these names can actually help you find the star in the sky. Hosted by: Reid Reimers ---------- Huge thanks go to the following Patreon supporter for he
From playlist SciShow Space