---
title: "IC 4642"
url: "https://spacecatalog.org/object/ic-4642"
release: "DR1"
licence: "CC-BY-SA-4.0"
citation: "SpaceCatalog. IC 4642 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ic-4642"
---

# IC 4642

IC 4642 is a planetary [nebula](https://spacecatalog.org/nebulae) in the constellation [Ara](https://spacecatalog.org/constellation/ara), 3006 parsecs from Earth as published by Stanghellini+ 2008 (about 9804 ly, converted by SpaceCatalog), shining at apparent magnitude 13.40 (B). Other catalogues list it as ESO 180-004, ESO 180-4 and HD 154952, among 10 designations in total.

## At a glance

- **WHAT IT IS:** Planetary nebula
- **HOW FAR:** 9804 ly — The light arriving now left it that long ago.
- **HOW BIG ON THE SKY:** 17″ — Small enough that the full Moon would cover it several times over.
- **HOW BRIGHT (B):** 13.40 — Faint: it takes a large telescope.
- **WHERE TO LOOK:** [Ara](https://spacecatalog.org/constellation/ara) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | Planetary nebula |
| DISTANCE FROM EARTH | 3006 pc (Stanghellini+ 2008) — ≈ 9804 ly, converted by SpaceCatalog · by Statistical distance scale for planetary nebulae (Stanghellini+ 2008) |
| APPARENT MAGNITUDE (B) | 13.40 |
| CONSTELLATION | Ara |
| RIGHT ASCENSION (J2000) | 17h 11m 45.2s |
| DECLINATION (J2000) | −55° 23′ 56.4″ |

## Catalogue data

### 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 |
| --- | --- |
| Apparent magnitude (B) | 13.40 |

### 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 |
| --- | --- |
| Radial velocity | 44 km/s |
| Redshift (z) | 0.000147 |
| Major axis | 0.28′ |

### OTHER NAMES AND NUMBERS

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

| Field | Value |
| --- | --- |
| OpenNGC type code | PN |
| Wikidata item | Q12071221 |
| Wikipedia article | IC 4642 |

### 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 |
| --- | --- |
| Distance catalogue entry | IC 4642 |

## Also known as

- ESO: ESO 180-004
- ESO: ESO 180-4
- HD: HD 154952
- IC: IC 4642
- IRAS: IRAS 17075-5520
- LEDA: LEDA 3099047
- PK: PK 334-09 1
- PN: PN G334.3-09.3
- UCAC3: UCAC3 70-402396
- UCAC4: UCAC4 173-185414

## Source

[OpenNGC](https://github.com/mattiaverga/OpenNGC) — CC-BY-SA-4.0

The producer asks: OpenNGC, Mattia Verga (github.com/mattiaverga/OpenNGC). Fields derived from it stay under CC BY-SA 4.0.

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

## Cite this page

SpaceCatalog. IC 4642 \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ic-4642

```bibtex
@misc{spacecatalog_ic-4642,
  author       = {{SpaceCatalog}},
  title        = {{IC 4642}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/ic-4642},
  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from OpenNGC.}
}
```

OpenNGC — CC-BY-SA-4.0

Acknowledgement the producer asks for: OpenNGC, Mattia Verga (github.com/mattiaverga/OpenNGC). 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/ic-4642