---
title: "IC 4557"
url: "https://spacecatalog.org/object/ic-4557"
release: "DR1"
licence: "CC-BY-SA-4.0"
citation: "SpaceCatalog. IC 4557 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ic-4557"
---

# IC 4557

IC 4557 is a spiral [galaxy](https://spacecatalog.org/galaxies) Sbc in the constellation [Boötes](https://spacecatalog.org/constellation/bootes), shining at apparent magnitude 15.71 (B). Other catalogues list it as 2MASX J15343692+3943435, LEDA 55483 and PGC 55483, among 5 designations in total.

## At a glance

- **WHAT IT IS:** Spiral galaxy
- **HOW BIG ON THE SKY:** 31″ — Small enough that the full Moon would cover it several times over.
- **HOW BRIGHT (B):** 15.71 — Faint: it takes a large telescope.
- **WHERE TO LOOK:** [Boötes](https://spacecatalog.org/constellation/bootes) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | Spiral galaxy Sbc |
| APPARENT MAGNITUDE (B) | 15.71 |
| CONSTELLATION | Boötes |
| RIGHT ASCENSION (J2000) | 15h 34m 36.9s |
| DECLINATION (J2000) | +39° 43′ 44.0″ |

## 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 |
| --- | --- |
| Hubble type | Sbc |

### 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) | 15.71 |
| Apparent magnitude (J) | 13.01 |
| Apparent magnitude (H band) | 12.36 |
| Apparent magnitude (K) | 12.15 |
| Surface brightness | 22.82 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 |
| --- | --- |
| Major axis | 0.52′ |
| Minor axis | 0.36′ |
| Position angle | 137° |

### 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 | Q3682462 |

## Also known as

- 2MASX: 2MASX J15343692+3943435
- IC: IC 4557
- LEDA: LEDA 55483
- PGC: PGC 55483
- SDSS: SDSS J153436.92+394343.9

## 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 4557 \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ic-4557

```bibtex
@misc{spacecatalog_ic-4557,
  author       = {{SpaceCatalog}},
  title        = {{IC 4557}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/ic-4557},
  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-4557