---
title: "NGC 171"
url: "https://spacecatalog.org/object/ngc-171"
release: "DR1"
licence: "CC-BY-SA-4.0"
citation: "SpaceCatalog. NGC 171 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ngc-171"
---

# NGC 171

NGC 171 is a spiral [galaxy](https://spacecatalog.org/galaxies) Sab in the constellation [Cetus](https://spacecatalog.org/constellation/cetus), 169.2 Mly from Earth, shining at apparent magnitude 12.25 (V). Other catalogues list it as 2MASX J00372152-1956032, ESO 540-006 and ESO 540-6, among 11 designations in total. It was discovered in 1784.

## At a glance

- **WHAT IT IS:** Spiral galaxy
- **HOW FAR:** 169.2 Mly — A luminosity distance, from its redshift — how faint it looks. The light itself left 180 million years ago.
- **HOW BIG ON THE SKY:** 2.1′ — Small enough that the full Moon would cover it several times over.
- **HOW BRIGHT (V):** 12.25 — A small telescope reaches it.
- **WHERE TO LOOK:** [Cetus](https://spacecatalog.org/constellation/cetus) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | Spiral galaxy Sab |
| DISTANCE FROM EARTH | 169.2 Mly ±16 — by redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc |
| APPARENT MAGNITUDE (V) | 12.25 |
| CONSTELLATION | Cetus |
| RIGHT ASCENSION (J2000) | 00h 37m 21.5s |
| DECLINATION (J2000) | −19° 56′ 03.3″ |
| DISCOVERED | 1784 |

## 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 |
| --- | --- |
| Hubble type | Sab |

### 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) | 12.98 |
| Apparent magnitude (V) | 12.25 |
| Apparent magnitude (J) | 10.38 |
| Apparent magnitude (H band) | 9.57 |
| Apparent magnitude (K) | 9.21 |
| Surface brightness | 22.98 mag/arcsec² |

### 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 | 3884 km/s |
| Redshift (z) | 0.013039 |
| Redshift (z, CMB frame) | 0.0120047 |
| Major axis | 2.06′ |
| Minor axis | 1.29′ |
| Position angle | 102° |

### WHEN IT WAS FOUND

Who first saw it, from where, and by what method.

| Field | Value |
| --- | --- |
| Discovered by | William Herschel |

### OTHER NAMES AND NUMBERS

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

| Field | Value |
| --- | --- |
| OpenNGC type code | G |
| Wikidata item | Q1035658 |
| Wikipedia article | NGC 171 |

## Also known as

- 2MASX: 2MASX J00372152-1956032
- ESO: ESO 540-006
- ESO: ESO 540-6
- ESO-LV: ESO-LV 540-0060
- IRAS: IRAS 00348-2012
- LEDA: LEDA 2232
- MCG: MCG -03-02-024
- NGC: NGC 171
- NGC: NGC 175
- PGC: PGC 2232
- SDSS: SDSS J003721.55-195603.2

## 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. NGC 171 \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ngc-171

```bibtex
@misc{spacecatalog_ngc-171,
  author       = {{SpaceCatalog}},
  title        = {{NGC 171}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/ngc-171},
  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/ngc-171