Constellation, Reticle
Reticulum
The reticle, a diamond-shaped sighting frame in the eyepiece of Nicolas Louis de Lacaille’s telescope. He used it to measure the southern stars from the Cape of Good Hope.
From New York the constellation Reticulum never rises above the horizon: it belongs to the other hemisphere’s sky.
From New York the constellation Reticulum never rises above the horizon: it belongs to the other hemisphere’s sky.
In the 3D sky
The sky over New York turned towards Reticulum. Drag to look around.
Loading 3D view...
Drag to look around, pinch or scroll to zoom.
Evening visibility over the year
Height of the constellation’s centre above the horizon at 10 pm local time on the 15th of each month, from New York. Above about 30° it is well placed.
Name and history
Nicolas Louis de Lacaille catalogued the southern stars from the Cape of Good Hope in 1751–52 with a small telescope. In its eyepiece sat a copper plate with a diamond-shaped opening, the reticle. Timing stars as they crossed it let him measure their positions. He honoured this tool in the sky and described it as ‘the little instrument used to draw up this catalogue’. Fittingly, it sits beside Horologium, the clock he used for that timing. He first called it le Reticule Romboide in 1756 and later Reticulus. The form Reticulum came from Benjamin Gould in 1879.
An older figure once stood here. The German astronomer Isaac Habrecht introduced Rhombus on a globe in 1621, a larger diamond that reached farther south. In 2024 the IAU named Alpha Reticuli Rhombus in its memory. In 1822 the British amateur Alexander Jamieson tried to replace Reticulum with a sundial, Solarium, but few followed him.
Sources: Ian Ridpath, Star Tales: Reticulum, IAU Working Group on Star Names (WGSN): Modern IAU star names
Brightest stars
| Star | Designation | Magnitude | Distance |
|---|---|---|---|
| Rhombus | α Ret | 3.33 | 162 light-years |
| β Ret | β Ret | 3.84 | 97 light-years |
| ε Ret | ε Ret | 4.44 | 60 light-years |
| γ Ret | γ Ret | 4.48 | 469 light-years |
| δ Ret | δ Ret | 4.56 | 526 light-years |
| κ Ret | κ Ret | 4.71 | 71 light-years |
| ι Ret | ι Ret | 4.97 | 319 light-years |
Facts
| Area | about 114 square degrees (82 of 88) |
|---|---|
| IAU abbreviation | Ret |
| Sky | Southern sky |
| Origin | First shown as le Reticule Romboide on Lacaille’s planisphere of 1756, from his observations at the Cape in 1751–52 |
| Stars brighter than magnitude 5 | 7 |
| Centre (J2000) | 4.0 h, -62° |
Deep-sky objects
Galaxies, clusters and nebulae brighter than magnitude 9, from the OpenNGC catalogue. Most need binoculars or a telescope and a dark sky.
No deep-sky object brighter than magnitude 9.
Boundaries: International Astronomical Union, via Astronomy Engine. Areas are computed from the boundaries by sampling (within about one percent). Names and lines: Stellarium. Stars: HYG Database. Deep-sky objects: OpenNGC. Calculated with Astronomy Engine, an open-source library verified against the US Naval Observatory and NASA JPL. Data sources
How to use this page
Choose your place and a night at the top. The answer and the 3D view show where the constellation is, when it is highest and whether it rises at all from where you are. The chart shows its stars and lines, and the tables list its brightest stars and the deep-sky objects inside it.
Frequently asked questions
When is a constellation best seen?
When it is highest in a dark sky, which the page gives for the night you pick. Each constellation is best placed in a particular season, because the stars rise about four minutes earlier every night.
Why can I not see a constellation from my place?
Constellations far south of the celestial equator never rise from northern places, and those far north never rise from southern ones. The page says when this is the case.
What are the constellation boundaries?
The International Astronomical Union divides the sky into 88 areas with official boundaries. The stick figures are only a drawing aid, the boundaries say which constellation a point in the sky belongs to.
Related guides
- How to learn the constellationsStart with one bright pattern you cannot miss, use it as a signpost to its neighbours, and come back a month later: the sky will have turned, and you will know a little more of it.
- Altitude and azimuth: finding things in the skyTwo angles tell you exactly where to look: which direction, and how high.
- Light pollution and dark skies: the Bortle scaleFrom a city centre you can count a few dozen stars. From a truly dark site you can count a few thousand, with the Milky Way bright enough to cast a shadow. The Bortle scale puts a number on the difference.
- Binoculars for stargazing: what to buy and what to look atA pair of 7x50 or 10x50 binoculars shows the craters of the Moon, the moons of Jupiter, dozens of star clusters and the Andromeda Galaxy, for a fraction of the cost of a telescope.