# Astronomical data in an Ephemeris

Philosophaie
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.

Homework Helper
Where did you see this ephemeris?

Philosophaie
Book:"The American Ephemeris for the 21st Century 2000-2050 at Midnight - Michelsen"

Mentor
Looks like the number of the star: the 7th brightest star in Leo.

Philosophaie
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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Philosophaie
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?

Homework Helper
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Philosophaie
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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Philosophaie
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

Philosophaie
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.

Staff Emeritus
Gold Member
Just curious, why are you using an ephemeris? They are used quite often by astrologists to calculate placements along the ecliptic.

Philosophaie
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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