---
title: "PG 1302-102"
url: "https://spacecatalog.org/object/pg-1302-102"
release: "DR1"
licence: "CC-BY-4.0"
citation: "SpaceCatalog. PG 1302-102 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/pg-1302-102"
---

# PG 1302-102

PG 1302-102 is a quasar in the constellation [Virgo](https://spacecatalog.org/constellation/virgo), 4.633 Gly from Earth.

Its brightness rises and falls on a cycle of about five years, which has been read as two [black holes](https://spacecatalog.org/black-holes) orbiting a few light-months apart. The reading is disputed — a warp in a single disc would do the same thing — and it is among the best candidates rather than a settled case.

## At a glance

- **WHAT IT IS:** Quasar
- **HOW FAR:** 4.633 Gly — A luminosity distance, from its redshift — how faint it looks. The light itself left 3.21 billion years ago.
- **WHERE TO LOOK:** [Virgo](https://spacecatalog.org/constellation/virgo) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | Quasar |
| DISTANCE FROM EARTH | 4.633 Gly — by luminosity distance from a published redshift, flat ΛCDM with H0 = 70 km/s/Mpc |
| CONSTELLATION | Virgo |
| RIGHT ASCENSION (J2000) | 13h 05m 33.0s |
| DECLINATION (J2000) | −10° 33′ 19.4″ |

## 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 |

### 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) | 0.2784 |

## Also known as

- Common name: PG 1302-102

## 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. PG 1302-102 \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/pg-1302-102

```bibtex
@misc{spacecatalog_pg-1302-102,
  author       = {{SpaceCatalog}},
  title        = {{PG 1302-102}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/pg-1302-102},
  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/pg-1302-102