---
title: "U Lep"
url: "https://spacecatalog.org/object/hd-31599"
release: "DR1"
licence: "CC-BY-SA-4.0"
citation: "SpaceCatalog. U Lep [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-31599"
---

# U Lep

U Lep is an A8/F2(I) white supergiant in the constellation [Lepus](https://spacecatalog.org/constellation/lepus), 1907 ly from Earth, shining at apparent magnitude 10.91 (V). Other catalogues list it as HD 31599 and HIP 22952.

## At a glance

- **WHAT IT IS:** White supergiant
- **HOW FAR:** 1907 ly — The light arriving now left it that long ago.
- **HOW BRIGHT (V):** 10.91 — A small telescope reaches it.
- **WHERE TO LOOK:** [Lepus](https://spacecatalog.org/constellation/lepus) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | A8/F2(I) white supergiant |
| MASS | 4.21 M☉ — Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate |
| DISTANCE FROM EARTH | 1907 ly — by parallax |
| APPARENT MAGNITUDE (V) | 10.91 |
| ABSOLUTE MAGNITUDE (V) | 2.08 |
| CONSTELLATION | Lepus |
| RIGHT ASCENSION (J2000) | 04h 56m 18.0s |
| DECLINATION (J2000) | −21° 13′ 02.0″ |

## Catalogue data

### WHAT KIND OF THING IT IS

What the object is in itself, rather than how it happens to look from here.

| Field | Value |
| --- | --- |
| Spectral type | A8/F2(I) |
| Surface temperature | 13 541 K |
| Luminosity | 12.8825 L☉ |
| Luminosity (bolometric) | 462.117 L☉ |
| Radius | 3.748 R☉ |
| Mass | 4.208 M☉ |
| Surface gravity (log g) | 3.83 |
| Variability | RR Lyrae variable (asymmetric light curve) |
| Variability type (GCVS) | RRAB |
| Variability period | 0.5814762 days |
| Reference epoch (HJD) | 2441352.3460 |

### HOW BRIGHT IT IS

What the light adds up to, measured through one filter at a time. A magnitude is a brightness on a backwards scale — the smaller the number, the brighter the object.

| Field | Value |
| --- | --- |
| Variable magnitude, brightest | 9.85 |
| Variable magnitude, faintest | 11.07 |

### WHERE IT IS AND HOW IT MOVES

Position, motion across the sky and the size it covers on it. These are measurements of the object as seen from here, so every one of them depends on where here is.

| Field | Value |
| --- | --- |
| Proper motion (RA) | 41.43 mas/yr |
| Proper motion (Dec) | −61.32 mas/yr |
| Radial velocity | 122 km/s |

### OTHER NAMES AND NUMBERS

The identifiers other catalogues file this object under, for anyone joining this data to theirs.

| Field | Value |
| --- | --- |
| Variable-star designation | U Lep |

### WHERE THESE FIGURES CAME FROM

Which catalogue, paper or model each of the fields above was read from, where the source named one.

| Field | Value |
| --- | --- |
| Spectral type from | SIMBAD (1988MSS...C04....0H, quality E) |
| Stellar parameters from | Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate |

## Also known as

- HD: HD 31599
- HIP: HIP 22952
- Variable star: U Lep

## Source

[HYG Database v4.1](https://github.com/astronexus/HYG-Database) — CC-BY-SA-4.0

The producer asks: HYG Database v4.1, Astronexus (github.com/astronexus/HYG-Database). Fields derived from it stay under CC BY-SA 4.0.

How this was made: https://spacecatalog.org/methods#source-hyg

## Cite this page

SpaceCatalog. U Lep \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-31599

```bibtex
@misc{spacecatalog_hd-31599,
  author       = {{SpaceCatalog}},
  title        = {{U Lep}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/hd-31599},
  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}
}
```

HYG Database v4.1 — CC-BY-SA-4.0

Acknowledgement the producer asks for: HYG Database v4.1, Astronexus (github.com/astronexus/HYG-Database). Fields derived from it stay under CC BY-SA 4.0.

The page itself, with its pictures, the sky map and the observing tools: https://spacecatalog.org/object/hd-31599