---
title: "PSR J1748-2446ad"
url: "https://spacecatalog.org/object/psr-j1748m2446ad"
release: "DR1"
licence: "No licence stated; the database is ATNF/CSIRO property under the CSIRO Legal Notice and Disclaimer"
citation: "SpaceCatalog. PSR J1748-2446ad [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/psr-j1748m2446ad"
---

# PSR J1748-2446ad

PSR J1748-2446ad is a millisecond pulsar in the constellation [Sagittarius](https://spacecatalog.org/constellation/sagittarius), 23 297 ly from Earth. It was discovered in 2006.

The fastest-spinning object known: 716 turns a second, which puts a point on its equator at nearly a quarter of the speed of light. It sits in a globular [cluster](https://spacecatalog.org/clusters), where close encounters between [stars](https://spacecatalog.org/stars) make the companion that spun it up far easier to acquire.

## At a glance

- **WHAT IT IS:** Millisecond pulsar
- **HOW FAR:** 23 297 ly — The light arriving now left it that long ago.
- **WHERE TO LOOK:** [Sagittarius](https://spacecatalog.org/constellation/sagittarius) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | Millisecond pulsar |
| DISTANCE FROM EARTH | 23 297 ly +6354 / −4111 — by pulsar parallax (timing or VLBI) |
| CONSTELLATION | Sagittarius |
| RIGHT ASCENSION (J2000) | 17h 48m 04.8s |
| DECLINATION (J2000) | −24° 46′ 45.0″ |
| DISCOVERED | 2006 |

## 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 |
| --- | --- |
| Spin period | 0.00139595 s |
| Spin-down rate | 0 s/s |

### 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 |
| --- | --- |
| Proper motion (RA) | −1.99 ±0.07 mas/yr |
| Proper motion (Dec) | −5.24 ±0.07 mas/yr |
| Position epoch | J2005.354 |
| Dispersion measure | 235.6 pc/cm³ |

### THE ORBIT

The shape of the path, where the object sits on it, and the instant those figures were true of. An orbit is a fit to observations and drifts away from the real one either side of its epoch.

| Field | Value |
| --- | --- |
| Binary orbit model | ELL1 |

### OTHER NAMES AND NUMBERS

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

| Field | Value |
| --- | --- |
| Associated with | GC:Terzan5 |

## Also known as

- ATNF: J1748-2446ad
- ATNF: PSR J1748-2446ad

## Source

[ATNF Pulsar Catalogue (Manchester+ 2005)](https://www.atnf.csiro.au/research/pulsar/psrcat) — No licence stated; the database is ATNF/CSIRO property under the CSIRO Legal Notice and Disclaimer

The producer asks: Manchester, R. N., Hobbs, G. B., Teoh, A. & Hobbs, M. 2005, AJ 129, 1993 (2005AJ....129.1993M); https://www.atnf.csiro.au/research/pulsar/psrcat

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

## Cite this page

SpaceCatalog. PSR J1748-2446ad \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/psr-j1748m2446ad

```bibtex
@misc{spacecatalog_psr-j1748m2446ad,
  author       = {{SpaceCatalog}},
  title        = {{PSR J1748-2446ad}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/psr-j1748m2446ad},
  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from ATNF Pulsar Catalogue (Manchester+ 2005).}
}
```

ATNF Pulsar Catalogue (Manchester+ 2005) — No licence stated; the database is ATNF/CSIRO property under the CSIRO Legal Notice and Disclaimer

Acknowledgement the producer asks for: Manchester, R. N., Hobbs, G. B., Teoh, A. & Hobbs, M. 2005, AJ 129, 1993 (2005AJ....129.1993M); https://www.atnf.csiro.au/research/pulsar/psrcat

The page itself, with its pictures, the sky map and the observing tools: https://spacecatalog.org/object/psr-j1748m2446ad