---
title: "SDSS J1148+5251"
url: "https://spacecatalog.org/object/sdss-j1148-5251"
release: "DR1"
licence: "CC-BY-4.0"
citation: "SpaceCatalog. SDSS J1148+5251 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/sdss-j1148-5251"
---

# SDSS J1148+5251

SDSS J1148+5251 is a quasar in the constellation [Ursa Major](https://spacecatalog.org/constellation/ursa-major), 202.2 Gly from Earth. Its mass is 3×10⁹ M☉. It was discovered in 2003.

The first quasar in the early universe found to contain carbon monoxide and dust. Both are made by [stars](https://spacecatalog.org/stars), so a [galaxy](https://spacecatalog.org/galaxies) less than a billion years old had already been through enough generations of them to enrich its own gas.

## At a glance

- **WHAT IT IS:** Quasar
- **HOW FAR:** 202.2 Gly — A luminosity distance, from its redshift — how faint it looks. The light itself left 12.5 billion years ago.
- **WHERE TO LOOK:** [Ursa Major](https://spacecatalog.org/constellation/ursa-major) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | Quasar |
| MASS | 3×10⁹ M☉ |
| DISTANCE FROM EARTH | 202.2 Gly — by luminosity distance from a published redshift, flat ΛCDM with H0 = 70 km/s/Mpc |
| CONSTELLATION | Ursa Major |
| RIGHT ASCENSION (J2000) | 11h 48m 16.6s |
| DECLINATION (J2000) | +52° 51′ 50.3″ |
| DISCOVERED | 2003 |

## 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 |
| --- | --- |
| Accretion state | quasar — a thin disc near its Eddington limit |
| Mass | 3×10⁹ M☉ |

### 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 |
| --- | --- |
| Redshift (z) | 6.47477 |

## Also known as

- Common name: SDSS J1148+5251

## Source

[SpaceCatalog curated data](https://spacecatalog.org/releases) — CC-BY-4.0

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

## Cite this page

SpaceCatalog. SDSS J1148+5251 \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/sdss-j1148-5251

```bibtex
@misc{spacecatalog_sdss-j1148-5251,
  author       = {{SpaceCatalog}},
  title        = {{SDSS J1148+5251}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/sdss-j1148-5251},
  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from SpaceCatalog curated data.}
}
```

SpaceCatalog curated data — CC-BY-4.0

The page itself, with its pictures, the sky map and the observing tools: https://spacecatalog.org/object/sdss-j1148-5251