Triangulum constellation
Triangulum is one of the 88 constellations, and it represents the triangle. It is highest in the sky at midnight around October 23, and its whole figure rises above the horizon from 90°N to 55°S.
Triangulum at a glance
- Represents
- the triangle
- Highest at midnight
- October 23
- Highest at 9 pm
- December 7
- Seen whole from
- 90°N to 55°S
- Stars in the figure
- 3 stars
- Origin
- Ptolemy's list, 2nd century
When to see Triangulum
Triangulum is highest in the sky at midnight around October 23 and at 9 pm around December 7. Each month it is highest about two hours earlier than the month before.
The times are local solar time. Clocks on summer time or daylight saving time read about one hour later.
| Date | Highest at |
|---|---|
| January 15 | 6:30 PM |
| February 15 | 4:20 PM |
| March 15 | 2:30 PM |
| April 15 | 12:30 PM |
| May 15 | 10:30 AM |
| June 15 | 8:30 AM |
| July 15 | 6:30 AM |
| August 15 | 4:30 AM |
| September 15 | 2:30 AM |
| October 15 | 12:30 AM |
| November 15 | 10:30 PM |
| December 15 | 8:30 PM |
Where to look for Triangulum
From the northern hemisphere
From 40°N, Triangulum rises in the east and sets in the west. It is highest around midnight on October 23, almost overhead.
From the southern hemisphere
From 35°S, Triangulum rises in the east and sets in the west. It is highest around midnight on October 23, 22° above the northern horizon.
Brightest stars in Triangulum
None of the stars of Triangulum is brighter than magnitude 2.3, so it is best seen from a dark place away from city lights. Its brightest stick-figure stars are about magnitude 3.
Triangulum in myth and history
Triangulum is one of the 48 constellations that the astronomer Ptolemy listed in the 2nd century.
Constellations next to Triangulum
Find Triangulum in your sky
Questions about Triangulum
Triangulum is highest in the sky at midnight around October 23 and at 9 pm around December 7. The weeks around those dates are the best time to look.
The whole figure of Triangulum rises above the horizon from 90°N to 55°S, and at least part of it rises from 90°N to 60°S.
Triangulum represents the triangle. Triangulum is one of the 48 constellations that the astronomer Ptolemy listed in the 2nd century.