ASTRONOMY · ROMANIA · 1900—2026
The birthday sky: the Moon, planets and the Sun’s constellation
Choose a date and a Romanian locality. The chart is set for 21:00 local time; the Sun is compared with the constellations at noon.
Choose a date and place
The calculation stays in this browser. Your date and place go nowhere.
Preparing the opening example for Bucharest, 1 January 2000.
02 · LOCAL SKY
The sky above you
Reference stars Moon Planets
North is at the top, east at the right. The circle’s edge is the geometric horizon; its centre is the zenith.
Reference stars use Hipparcos J2000.0 positions without proper motion; the Moon and planets are calculated for the chosen date and coordinates.
03 · RESULT
The Bucharest example
Chart at 21:00 · Sun at 12:00
The Moon, Sun and planets for Bucharest, 1 January 2000.
The summary is calculated in your browser from the date and locality you choose.
TWO WAYS TO DESCRIBE THE SKY
A zodiac sign and a constellation are different things
A sign uses one of 12 equal sectors of the tropical zodiac. The Sun’s constellation follows the unequal Delporte boundaries, projected for epoch B1875.0. The table tracks the Sun day by day in the selected year.
| Date span | Tropical sign | Constellation |
|---|---|---|
| The table will be calculated locally when the data loads. | ||
Transition dates are calculated for local noon; they are not fixed dates that apply to every year.
HOW THE CALCULATION WORKS
A sky reference, not the exact time of birth
A date alone cannot fix the sky at the minute of birth. The chart therefore uses 21:00 local time, while the Sun’s constellation is calculated separately for 12:00. Sunrise and sunset mark the conventional crossing of the Sun’s centre at −0.833°.
Coordinates are representative points for localities. The horizon is geometric: terrain, buildings and observer elevation are not included. Civil time and historical daylight-saving rules follow the IANA Europe/Bucharest history in tzdata 2026e.
Positions use published astronomical algorithms by Jean Meeus and are compared during the build with JPL DE440. To find the Sun’s constellation, its position is transformed into the B1875.0 frame and compared with the CDS VI/42 catalogue boundaries.
SOURCES AND CONTEXT
Data behind the chart
The calculator covers dates from 1 January 1900 through 2026-10-03 and Romanian localities retained from GeoNames.
- JPL Horizons and the DE440 ephemerisReference for checking celestial positions.
- Jean Meeus, Astronomical Algorithms, 2nd editionChapters 15, 25, 32, 41, 47, 48 and 49.
- CDS VI/42 · Delporte constellation boundariesAstronomy catalogue used for the Sun’s constellation.
- IAU 2006 Resolution B1 · P03 precession theoryGeneral precession is about 50.288 arcseconds per year.
- IAU SOFA library · IAU 2006 precessionThe P03 series used by the independent celestial-frame transform.
- IANA Time Zone Database · release 2026eHistorical civil time for Europe/Bucharest.
- GeoNames RomaniaLocality data · CC BY 4.0.
- ESA Hipparcos Main CatalogueReference stars · credit ESA 1997 · CC BY-NC 3.0 IGO.