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Episode 2 - Celestial Coordinates and Different Types of Telescopes

(Pawling Public Radio 103.7 FM)

Welcome to The Astronomical Almanac.
I am your host - Bob Antol. I am a local astronomer in the Pawling area (Poughquag specifically), with a passion for all things astronomical.

Astronomy is the branch of science that deals with celestial objects, space, and the physical universe as a whole. This show, The Astronomical Almanac, will make you more comfortable with these concepts so you will be able to recognize, grasp and appreciate the universe around us.

This is the The Astronomical Almanac on WPWL - Pawling Public Radio - 103.7 FM - Pawling, New York.
And today's episode is entitled Celestial Coordinates and Different Types of Telescopes.


Old Business


  >   The first segment of the program is something I call Old Business. This will be devoted to answering any questions from the previous episodes or to correct anything I may have said in error.

The Astronomical Almanac will have the following format:

  1. Old Business - this segment here.
  2. Expanding Your Astronomical Vocabulary - devoted to defining astronomical terms.
  3. What's Up in the Sky This Week? - from planets to meteor showers to the space station and more!
  4. Astronomical Curiosities - exploring unique aspects of the world of astronomy.
  5. Did You Know? - a fun-filled trivia section.
  6. The Buffer Zone - personal recollections from my life as an amateur astronomer.

  <   This concludes the Old Business portion of the program. Next up ... Expanding Your Astronomical Vocabulary ...


Expanding Your Astronomical Vocabulary


Celestial Coordinates


  >   Each week, a term (or two) will be defined laying the groundwork for a more general understanding of astronomy. This week, in Expanding Your Astronomical Vocabulary, I will be discussing ...

Discuss the following:

    Latitude / Longitude Earth and Sun
    Celestial Coordinates Equinoxes and Solstices

Why is 0 degrees longitude in Greenwich?
In 1884, an international conference decided that the Greenwich Meridian, as defined by the Airy Transit Circle at the Royal Observatory, Greenwich, should be adopted as the Prime or Zero Meridian for the World. Additionally:
  1. The fact that the USA had already chosen Greenwich as the basis for its own national time zone system.
  2. In the late 19th century, 72% of the world's commerce depended on sea-charts which used Greenwich as the Prime Meridian.

Right Ascension
Right ascension (abbreviated RA) is the angular distance measured eastward along the celestial equator from the vernal equinox to the hour circle of the point in question. When combined with declination, these astronomical coordinates specify the direction of a point on the celestial sphere in the equatorial coordinate system.
1 hour = 15 degrees

Declination
The angular distance of a point north or south of the celestial equator.

Reference Material
How To Read Sky Coordinates from the One-Minute Astronomer
What Are Celestial Coordinates? from Sky and Telescope

  <   This concludes the Expanding Your Astronomical Vocabulary portion of the program. Next up ... What's Up in the Sky This Week ...


What's Up in the Sky This Week


  >   In this next segment of the program (What's Up in the Sky This Week), I will highlight events in the sky that are of interest to the average person. First up ...

  • Evening sky highlights
    10 Oct 2017 Comet C/2017 O1 ASAS SN at magnitude 8 and improving (binocular object)

    First seen by All Sky Automated Survey for Supernovae (ASAS-SN)


    Comet Path

    Position

    Grids

    Info

    More details at Space.com

    12 Oct 2017 Asteroid 2012 TC4 (which measures somewhere between 10 m and 30 m wide), will pass 43,500 km above our planet's surface, about 1/8th the distance to the Moon. At peak brightness, 2012 TC4 will shine like a 13th magnitude star as it zips through the constellations Capricornus and Sagittarius.

  • Morning sky highlights
    15 Oct 2017 Regulus is 0.2 degrees south of the Moon

  • Upcoming meteor showers
    22 Oct Orionid meteor shower (class I major shower)

    2017 Major Meteor Showers (Class I)

    Shower Activity Period Maximum Radiant Velocity r Max. Time Moon
    Date S. L. R.A. Dec. km/s ZHR
    Orionids (ORI) Aug 25-Nov 19 Oct 22 208.9 06:24 +15.5 67.1 2.5 15 0500 03

  <   This concludes the What's Up in the Sky This Week portion of the program. Next up ... Astronomical Curiosities ...


Astronomical Curiosities


Different Types of Telescopes


  >   In this segment, called Astronomical Curiosities, I will explore a unique and different aspect of the world of astronomy. Today's curiosity is ...

This is the The Astronomical Almanac on WPWL - Pawling Public Radio - 103.7 FM - Pawling, New York ... streaming live at pawlingpublicradio.org.

Discuss the following:

    Refractor Reflector
    Compound (Schmidt-Cassegrain) Compound (Ritchey-Chretien)

     


     

    Dobsonian (on a Rocker Box) Alt-Azimuth
    Equatorial Equatorial (Paramount ME)

Notes
Choose a telescope based on your observing interests, lifestyle, and budget.
  • Many (arguably most) good starter scopes cost $400 or more, though some superb choices are available for under $250.
  • Big scopes show more and are easier to use than small ones.
  • But don't overlook portability and convenience - the best scope for you is the one you'll actually use.
The telescope you want has two essentials:
  • high-quality optics and
  • a steady, smoothly working mount.
Avoid telescopes that are advertised by their magnification - especially implausibly high powers like 600x.
  • For most purposes, a telescope's maximum useful magnification is 50 times its aperture in inches (or twice its aperture in millimeters). So you'd need a 12-inch-wide scope to get a decent image at 600x.

Resources
How to Choose Your First Telescope from Sky and Telescope
Best Telescope for Beginners from Space.com

  <   This concludes the Astronomical Curiosities portion of the program. Next up ... Did You Know? ...


Did You Know?


  >   This segment of the program will be devoted to little bits of trivia that can be shared at parties, family get-togethers, reunions. Hey, the next time you are at a bar and there is a lull in the conversation, simply yell out Did You Know ... and share the following!

Galileo Galilei is often incorrectly credited with the invention of the telescope. Historians now think the Dutch eyeglass maker Johannes Lippershey was its creator. Galileo was probably the first to use the device to study the heavens to make his discoveries.

  <   This concludes the Did You Know? portion of the program. Next up ... The Buffer Zone ...


The Buffer Zone


  >   If there is still time left in the program, this segment (The Buffer Zone) will be devoted to 'personal recollections' of the things that initially got me interested in astronomy.

Astronomy is "free".

The Astronomical Almanac can be found on the web at http://www.stargate4173.com/wpwl/.

You will be able to see:

  • The format of the show
  • Links to the music from the show
  • Links to the notes for each episode
  • My bio

  <   This concludes the The Buffer Zone portion of the program.

This has been The Astronomical Almanac
on WPWL - Pawling Public Radio - 103.7 FM - Pawling, New York.
I have been your host - Bob Antol.
I hope you enjoyed today's show and are a little more comfortable with the topics I discussed so you can now more easily recognize, grasp and appreciate the universe around us.
On next week's show, the episode will be entitled Astronomical Units and Astronomical Apps.

Clear skies ... and don't forget ... to look up!

copyright © 2017 Robert A. Antol