Double Pulsar
ILLUSTRATION FROM PERIOD 22.7 MS · FIELD 6.4×10⁹ G · CHARACTERISTIC AGE 2.04×10⁸ YR · SPIN-DOWN 5.94×10³³ ERG/S
OVERVIEW
] NEUTRON STARDouble Pulsar is a in the constellation Puppis, 3749 from Earth. Other catalogues list it as J0737-3039A and PSR J0737-3039A. It was discovered in 2003.
The only known binary in which both neutron stars are seen to pulse, going round each other in two and a half hours. Seeing both sides of the system turns it into the most stringent test of general relativity anywhere, and it has passed every version of that test so far.
- WHAT IT IS
- Millisecond pulsar
- HOW FAR
- 3749
The light arriving now left it that long ago.
OBSERVING
] FROM WHERE YOU AREWhat it takes to see Double Pulsar 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 Double Pulsar is worth going out for.
APPARENT PLACE
] EQUINOX J2026.7Where 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
- 14.0
- PROPER MOTION SINCE
- none published
Computed for 2026-09-04 00:00 UT. No proper motion is published for Double Pulsar, so nothing here moves the object; what separates this from the catalogued position above is the coordinate grid turning under it — about fifty arcseconds a year of precession since 2000, and the small nodding of the Earth’s axis on top of that. Aberration and refraction are not included, and neither is parallax; each is under an arcminute, which is also about as well as the catalogued position is known. 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.
- Surface magnetic field
- 6.4×10⁹ G
- Spin period
- 0.0226994
- Spin-down rate
- 1.76×10⁻¹⁸ /s
- Characteristic age
- 2.04×10⁸ yr
- Spin-down luminosity
- 5.94×10³³ erg/s
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.
- Radio flux at 1400 MHz
- 3.06 mJy
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.
- Dispersion measure
- 48.92 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
- DDS
ALSO KNOWN AS
] 5 DESIGNATIONS- ATNF J0737-3039A
- ATNF PSR J0737-3039A
- Common name Double pulsar
- Common name Double Pulsar
- Common name PSR J0737-3039A
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 114.4635 -30.6613
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. Double Pulsar [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/psr-j0737m3039a
@misc{spacecatalog_psr-j0737m3039a,
author = {{SpaceCatalog}},
title = {{Double Pulsar}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/psr-j0737m3039a},
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) — Free to use with attribution; cite Manchester+ 2005 (2005AJ....129.1993M). Citing this page does not replace citing that catalogue.