---
title: "3C 345"
url: "https://spacecatalog.org/object/3c-345"
release: "DR1"
licence: "CC-BY-4.0"
citation: "SpaceCatalog. 3C 345 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/3c-345"
---

# 3C 345

3C 345 is a quasar in the constellation [Hercules](https://spacecatalog.org/constellation/hercules), 11.28 Gly from Earth.

Knots in its radio jet appear to travel faster than light. They do not: the jet points close to our direction, so it nearly keeps pace with the light it emits and the arrival times of successive images are squeezed together.

## At a glance

- **WHAT IT IS:** Quasar
- **HOW FAR:** 11.28 Gly — A luminosity distance, from its redshift — how faint it looks. The light itself left 5.63 billion years ago.
- **WHERE TO LOOK:** [Hercules](https://spacecatalog.org/constellation/hercules) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | Quasar |
| DISTANCE FROM EARTH | 11.28 Gly — by luminosity distance from a published redshift, flat ΛCDM with H0 = 70 km/s/Mpc |
| CONSTELLATION | Hercules |
| RIGHT ASCENSION (J2000) | 16h 42m 58.8s |
| DECLINATION (J2000) | +39° 48′ 37.0″ |

## 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 |
| --- | --- |
| 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) | 0.59280791 |

## Also known as

- Common name: 3C 345

## 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. 3C 345 \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/3c-345

```bibtex
@misc{spacecatalog_3c-345,
  author       = {{SpaceCatalog}},
  title        = {{3C 345}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/3c-345},
  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/3c-345