PSR J1748-2446ad
ILLUSTRATION FROM PERIOD 1.4 MS
OVERVIEW
NEUTRON STARPSR J1748-2446ad is a in the constellation Sagittarius, 23 297 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, where close encounters between stars make the companion that spun it up far easier to acquire.
- WHAT IT IS
- Millisecond pulsar
- HOW FAR
- 23 297
The light arriving now left it that long ago.
OBSERVING
FROM WHERE YOU AREWhat it takes to see PSR J1748-2446ad for yourself. Everything in this part of the page is worked out for a real horizon, a real night and the equipment you say you have.
Say where you are, and this line says when PSR J1748-2446ad is worth going out for.
APPARENT PLACE
EQUINOX J2026.8Where a telescope has to be pointed today, which is not quite where the catalogue records the object: the coordinate grid itself has turned since the year 2000 the catalogue is referred to.
- RIGHT ASCENSION
- DECLINATION
- GRID TURNED SINCE
- 22.6
- PROPER MOTION SINCE J2005.4
- 0.12
Computed for 2026-10-23 00:00 UT. Two things separate it from the catalogued position above: PSR J1748-2446ad has moved under its own proper motion, and the coordinate grid has turned under it — about fifty arcseconds a year of precession since 2000, and the small nodding of the Earth’s axis on top of that. The motion is counted from J2005.4, the epoch the position above was measured at — a different thing from the equinox its coordinates are named for, even where the two fall in the same year. The catalogue it came from publishes no error for that position, so nothing here says how far this arithmetic can be trusted — the digits above are as precise as the place they were computed from, and no more. Aberration, parallax and refraction are left out. Aberration swings every position by up to twenty arcseconds over a year; parallax stays under an arcsecond for all but the nearest stars; refraction is nothing overhead and about half a degree at the horizon, where it answers to the air, not the sky. The same figure for any date.
CATALOG DATA
8 FIELDSThe raw catalogue values, as the source published them, with the error bars where one was published — sorted by what each set of figures is about rather than by the order they happened to be stored in.
WHAT KIND OF THING IT IS
What the object is in itself, rather than how it happens to look from here.
- Spin period
- 0.00139595
- Spin-down rate
- 0 /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.
- Proper motion (RA)
- −1.99 ±0.07
- Proper motion (Dec)
- −5.24 ±0.07
- 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.
- Binary orbit model
- ELL1
OTHER NAMES AND NUMBERS
The identifiers other catalogues file this object under, for anyone joining this data to theirs.
- Associated with
- GC:Terzan5
ALSO KNOWN AS
2 DESIGNATIONS- ATNF J1748-2446ad
- ATNF PSR J1748-2446ad
LOOK IT UP ELSEWHERE
1 SERVICEEach link carries the identifier printed beside it. Nothing on this page is a measurement of our own, so a number that disagrees with one of these is worth reporting — and a service that has never catalogued this object under this name will say so plainly.
- VizieR5″ around 267.0200 -24.7792
Every published table with a row at this position, searched by coordinates rather than by name.
CITE THIS PAGE
DR1This page is live and its numbers move when an upstream refreshes, so the citation names the release the rows belong to rather than the day you read them. The release itself is frozen, republished as a bundle, and is what a data-availability statement should point at.
SpaceCatalog. PSR J1748-2446ad [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/psr-j1748m2446ad
@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).}
}The values above were taken from ATNF Pulsar Catalogue (Manchester+ 2005) — No licence stated; the database is ATNF/CSIRO property under the CSIRO Legal Notice and Disclaimer. Citing this page does not replace citing that catalogue.
That catalogue asks for this acknowledgement: 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
RECENT ACTIVITY
1 ITEMS- Dark energy effects on surface gravitational redshift and Keplerian frequency of neutron stars2024-08-31 · arXiv · PAPER · Jia-Jing He, Yan Xu, Yi-Bo Wang, Xiu-Lin Huang, Xing-Xing Hu, Yu-Fu Shen
arXiv · UPDATED DAILY