---
title: "NGC 6644"
url: "https://spacecatalog.org/object/ngc-6644"
release: "DR1"
licence: "CC-BY-SA-4.0"
citation: "SpaceCatalog. NGC 6644 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ngc-6644"
---

# NGC 6644

NGC 6644 is a planetary [nebula](https://spacecatalog.org/nebulae) in the constellation [Sagittarius](https://spacecatalog.org/constellation/sagittarius), shining at apparent magnitude 10.70 (V). Other catalogues list it as ESO 522-033, ESO 522-33 and HD 170839, among 6 designations in total. It was discovered in 1880.

## At a glance

- **WHAT IT IS:** Planetary nebula
- **HOW BIG ON THE SKY:** 2″ — Small enough that the full Moon would cover it several times over.
- **HOW BRIGHT (V):** 10.70 — A small telescope reaches it.
- **WHERE TO LOOK:** [Sagittarius](https://spacecatalog.org/constellation/sagittarius) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | Planetary nebula |
| APPARENT MAGNITUDE (V) | 10.70 |
| CONSTELLATION | Sagittarius |
| RIGHT ASCENSION (J2000) | 18h 32m 34.7s |
| DECLINATION (J2000) | −25° 07′ 45.7″ |
| DISCOVERED | 1880 |

## 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) | 12.20 |
| Apparent magnitude (V) | 10.70 |
| Apparent magnitude (J) | 11.56 |
| Apparent magnitude (H band) | 11.60 |
| Apparent magnitude (K) | 10.63 |

### 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 | 194 km/s |
| Redshift (z) | 0.000647 |
| Major axis | 0.04′ |

### WHEN IT WAS FOUND

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

| Field | Value |
| --- | --- |
| Discovered by | Edward Charles Pickering |

### 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 | Q1146858 |
| Wikipedia article | NGC 6644 |

## Also known as

- ESO: ESO 522-033
- ESO: ESO 522-33
- HD: HD 170839
- IRAS: IRAS 18295-2510
- NGC: NGC 6644
- PN: PN G008.3-07.3

## 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 6644 \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ngc-6644

```bibtex
@misc{spacecatalog_ngc-6644,
  author       = {{SpaceCatalog}},
  title        = {{NGC 6644}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/ngc-6644},
  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-6644