Astronomical data in an Ephemeris

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Discussion Overview

The discussion revolves around the interpretation of astronomical data presented in an ephemeris, specifically focusing on the notation such as "07Leo38.2" and its components, including Right Ascension (RA) and Declination (Dec). Participants also explore the application of this data in calculations related to celestial positions and movements.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant questions the meaning of "07" in "07Leo38.2" and whether it relates to the constellation or the brightness of stars.
  • Another participant suggests that "07" could represent the 7th brightest star in Leo.
  • There is a proposal that "38.2" refers to Declination, with a participant noting the typical ranges for Right Ascension and Declination in Leo.
  • A later reply asserts that the ephemeris data is based on Right Ascension, providing a conversion method for "07Leo38.2" into degrees.
  • One participant expresses uncertainty about the specific meaning of "07:23" in the context of the ephemeris entries.
  • Another participant mentions using the ephemeris to compare RA and Dec data of planets and discusses the obliquity of the ecliptic.
  • There is a mention of the ephemeris being used by astrologists, prompting a question about its purpose in the discussion.

Areas of Agreement / Disagreement

Participants express differing views on the interpretation of the ephemeris data, particularly regarding the meaning of the numbers and their relation to RA and Dec. The discussion remains unresolved with multiple competing interpretations presented.

Contextual Notes

Participants reference various sources, including a specific book on ephemeris data and Wikipedia, indicating potential discrepancies in the data they are examining. There are also mentions of specific celestial events and positions that may not be universally agreed upon.

Who May Find This Useful

This discussion may be of interest to those studying astronomy, particularly in relation to celestial navigation, ephemeris data interpretation, and the application of RA and Dec in astronomical calculations.

Philosophaie
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Astronomical data in an Ephemeris comes in the form:

07Constellation38.2
or
07Leo38.2

What is the value, 07, represent? I think I understand the Constellation the object is passing thru like the planet and the moon. Also what does the 38.2 stand for? Do they stand for Right Ascension and Declination?

Second part, the Galactic Center listed at 26Sag59.5 for March and Vernal Point, 05Pis06.47, are there any equations for the motion of these using Julian Date and other parameters.
 
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Where did you see this ephemeris?
 
Book:"The American Ephemeris for the 21st Century 2000-2050 at Midnight - Michelsen"
 
Looks like the number of the star: the 7th brightest star in Leo.
 
The true moon's node is in Leo till 4-10-10. Not sure about the brightness of stars in Leo.Was it near Regulus? Vesta is now in that constellation?

I still want to know what what is the meaning of 07Leo38.2 or anything similar (zodiac constellations and the numbers before and after).
 
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Leo's Right Ascension varies from 145 to 177 deg. Declination varies between 6-25deg. It must be Declination that they are referring to in 07Leo38.2. Is that correct?
 
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The above RA and DEC come from Wikipedia.

My data page looks exactly like yours except it was off by a few decimal places. I see there was a partial Soloar Eclipse on DEc 25,2000 @17:34:35. Not sure what the 07:23 means.

Is it the declination listed in the entries in this ephemeris:

07Leo38.2 = 7deg 38.2min=Dec?
 
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The above post is wrong. The ephemeris goes by Right Ascension. The ephemeris cycles from 0 to 30 with a constellation sign and numbers before and after. The numbers before are the degrees and after are the minutes.

07Leo38.2 = 7deg 38.2min = 7.63666667Deg

The House of Leo is 150<=RA<=180. To get the RA position add Deg to 150.

RA = 157.6366667deg
 
  • #10
I know that the Ephemeris data is actually the longitude of the Earth. I need a way to convert "07Leo38.2" to the Right Ascension.
 
  • #11
Just curious, why are you using an ephemeris? They are used quite often by astrologists to calculate placements along the ecliptic.
 
  • #12
I am using it to compare the RA and DEC data of the planets I have. I will use the Ephemeris data to give a reasonable approximation of the longitude. I read that the ellptic is 23.4deg (Obliquity) displaced from the Celestial Equator. I think I can base my calculations on that.
 
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