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Observation Settings

Or select it on the map:
This Earth map fragment is intended to illustrate celestial motion across the sky, emphasizing both bearing and elevational perspectives. The map's center point corresponds to the transit, showcasing celestial objects at their highest point, while elevation gradually decreases towards the map edges. This dynamic representation offers insights into the changing positions of celestial bodies with a focus on their bearing and elevational trajectories.
Your location: Santa Clara, United States
Timezone:
Latitude:
37.3541
Longitude:
-121.955

Castor Position and Visibility Tonight

Castor

Where is Castor right now?

Castor is located in the constellation Gemini. At the current time, it is above the horizon at an altitude of 25 degrees toward the northeast from your location, with an apparent magnitude of 1.58.
Twilight begins at 21:54 local time, and at that moment, Castor will appear at an altitude of 25 degrees toward the northeast.

Castor Visibility on April 25

Castor is visible from sunset through most of the night

Castor Rise and Set Timetable

TimeElevation
Moon Rise, 48.9% illuminated 11:0425°
Castor transit16:3085°
Sunset17:5073°
Civil sunset18:1867°
Twighlight start18:5260°
Astrosession begin19:2753°
Castor set00:22
Moon Set01:21-8°
Astrosession end02:44-17°
Castor rise08:34

Track Castor Position Throughout the Night

← Sat, 25 April 2026 →

Elevation (degrees)
Time
Altitude
Azimuth
Shift the map to change the time and observe Castor changing position in the night sky.

Castor - Multiple Star System

Castor is the second-brightest star in the constellation Gemini and the twenty-fourth-brightest star in the night sky. It is a multiple star system located about 51 light-years away from Earth.

Castor has an apparent magnitude of 1.58 and consists of six main stars. It is one of the most prominent stars in the winter sky in the Northern Hemisphere.

Finder Chart for Castor

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Object nameCastor
Field of view
Limiting magnitude
Castor coordinates7.576633999999999, 31.888276
Center coordinates7.576633999999999, 31.888276

Castor Passage Through Night

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Current position of Castor

Time21:54
Latitude37.3541
Longitude-121.955
Castor elevation25°
Castor Azimuth68°
Here you can see the current position of the Castor on the map, as well as its positions for rise and set. This tool allows you to track the Castor's movement throughout the night, providing you with accurate and up-to-date information.

Annual motion of Castor


Castor will be visible until May, 27, when it will move too close to the Sun. During this time, its proximity to the Sun will cause it to disappear from the night sky, making it unobservable for a while.
Time
DateSun, 26 April 2026
Twighlight start19:27
Twighlight end02:41
Twighlight duration7h 14m
Rise08:34
Set00:18
Elevation at transit85°
Transit time16:26
Equatorial coordinatesRA: 07h 34m 35s", Dec: 31° 53' 17s
Magnitude2
ConstellationGemini
The graph illustrates the annual visibility pattern of a Castor, providing a comprehensive overview of its daily appearances and transit times throughout the year.
The graph is structured with the vertical axis showing the hours of the day, ranging from 12 AM to 12 AM the next day, while the horizontal axis spans each day of the year.
The reddish shaded area indicates the periods when the Castor is above the horizon, visible to observers. The white line marks the times when the celestial object reaches its highest point in the sky each day, known as the transit.
You can also view detailed visibility information in a dedicated table, including exact rise, transit, and set times for each date.

Astrometric & Physical Parameters of Castor

Coordinates & Visibility

Right Ascension7.576633999999999°
Declination31.888276°
Magnitude1.58
ConstellationGemini
Elevation25°
Azimuth67.8°