Star Stars · In Scorpius
Lesath
Lesath, υ Scorpii, is a blue-white subgiant in Scorpius: the 116th brightest star in the night sky.
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- Constellation
- Scorpius
- Designation
- υ Scorpii
- Apparent magnitude
- 2.70 · 116th brightest star in the night sky
- Spectral class
- B2IV
- Distance
- 576 light-years
- Highest at midnight
- mid June
- Position (J2000)
- RA 17h 31m · Dec −37° 18′
A blue-white subgiant, around 26,000 K, like Rigel and Spica. About 33× brighter than the faintest star the eye can see. Gives off about 2,200 times the Sun's visible light. The light you are seeing left around 1450.
When to see it
On the night of Fri 11 Jun 2027, when it is highest around midnight, on each city’s own clock:
| From | Rises | Highest | Sets |
|---|---|---|---|
| London GMT+1 | 00:06 | 01:12 · 1° | 02:18 |
| New York EDT | 21:51 | 01:07 · 12° | 04:22 |
| Singapore GMT+8 | 19:23 | 01:18 · 51° | 07:12 |
| Sydney GMT+10 | 16:07 | 00:09 · 87° | 08:10 |
Common questions
- Can I see it from 50° north?
- Only just. At its highest it is 3° above the southern horizon, so it needs a clear, flat view that way and clean air.
- Can I see it from 35° south?
- Yes, and well placed: at its highest it passes almost overhead, 88° up, above most of the air’s haze.
- When is the best time of year to see it?
- Around mid June, when it stands opposite the Sun and is highest at midnight. It comes round about two hours earlier each month, so by mid September it is highest in the early evening, and in mid March not until the hours before dawn.
- How far away is it, and how bright?
- It is 576 light-years away, and shines at magnitude 2.70 in our sky. From that far, the Sun would be a star of magnitude 11.0: too faint for anything less than a telescope.
- Naked eye, binoculars or telescope?
- The naked eye, even from a city: at magnitude 2.70 it is brighter than the faintest stars a city sky still shows, about magnitude 4.5.
Look for
Start from Shaula: Lesath is 36′ west of it, about a Moon width.
Look for
From 50° north it barely clears the horizon, at 3°; from 35° north it climbs to 18°; from the equator it climbs to 53°; from 35° south it climbs to 88°.
Science
Lesath’s surface is about 26,000 K, some 20,200 K hotter than the Sun’s 5,772 K, so its light is strongest at about 110 nm, in the ultraviolet, past the violet end of what the eye can see, where the Sun’s is strongest at 500 nm. Moved to 33 light-years, the distance astronomers compare stars at, it would shine at magnitude −3.5, brighter than Sirius, the brightest star in our sky.
Did you know
Against Shaula, the brighter star the hop starts from: Shaula looks 2.7 times as bright as Lesath in our sky; Shaula is 571 light-years away and Lesath 576 light-years, so side by side Shaula would give off 2.7 times as much light as Lesath.
Science
Lesath is the 138th nearest to us of the 156 stars on these pages with a measured distance. Its nearest neighbour among them in space is Shaula, about 8 light-years from it; on our sky the two are 36′ apart.
Look for
The Sun passes 14° north of Lesath around mid December, when it is highest at noon, in daylight: the weeks either side are its worst time of year. From 50° north it is above the horizon for about 3 hours a day, from 35° north about 8 and from 35° south about 16. It is 2° from the plane of the Milky Way, inside the band a dark sky shows.