PSR B1919+21
ILLUSTRATION FROM PERIOD 1.34 S · FIELD 1.36×10¹² G · CHARACTERISTIC AGE 1.57×10⁷ YR · SPIN-DOWN 2.23×10³¹ ERG/S
OVERVIEW
] NEUTRON STARPSR B1919+21 is a in the constellation Vulpecula, 2629 from Earth. Other catalogues list it as J1921+2153, PSR J1921+2153 and LGM-1. It was discovered in 1967.
The first pulsar found, in a chart-recorder trace Jocelyn Bell noticed in 1967 as a bit of scruff repeating every 1.34 seconds. It was labelled LGM-1 — little green men — while the possibility of an artificial signal was ruled out, which took finding a second one somewhere else in the sky.
- WHAT IT IS
- Pulsar
- HOW FAR
- 2629
The light arriving now left it that long ago.
OBSERVING
] FROM WHERE YOU AREWhat it takes to see PSR B1919+21 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 B1919+21 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
- 16.4
- PROPER MOTION SINCE J1993.0
- 1.22
Computed for 2026-10-19 00:00 UT. Two things separate it from the catalogued position above: PSR B1919+21 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 J1993.0, 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 catalogued place is itself known to 49 mas, which is what this arithmetic can be trusted to however many digits it is printed with. 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
] 11 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
- 1.36×10¹² G
- Spin period
- 1.3373
- Spin-down rate
- 1.35×10⁻¹⁵ /s
- Characteristic age
- 1.57×10⁷ yr
- Spin-down luminosity
- 2.23×10³¹ 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
- 19 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.
- Proper motion (RA)
- 17 ±4
- Proper motion (Dec)
- 32 ±6
- Position epoch
- J1993.031
- Position known to
- 49 mas
- Dispersion measure
- 12.44 pc/cm³
ALSO KNOWN AS
] 6 DESIGNATIONS- ATNF B1919+21
- ATNF J1921+2153
- ATNF PSR B1919+21
- ATNF PSR J1921+2153
- Common name LGM-1
- Common name PSR J1921+2153
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 290.4367 +21.8840
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 B1919+21 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/psr-j1921p2153
@misc{spacecatalog_psr-j1921p2153,
author = {{SpaceCatalog}},
title = {{PSR B1919+21}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/psr-j1921p2153},
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
] 2 ITEMS- First Constraint on Axion-Photon Coupling $g_γ$ from Neutron Star Observations2025-06-09 · arXiv · PAPER · Jun-Chen Wang, Shunshun Cao, Jinchen Jiang, Yandong Liu, Qing-Hong Cao, Lijing Shao
- Rapid Rotation of Polarization Orientations in PSR B1919+21's Single Pulses: Implications On Pulsar's Magnetospheric Dynamics2024-11-28 · arXiv · PAPER · Shunshun Cao, Jinchen Jiang, Jaroslaw Dyks, Kejia Lee, Jiguang Lu, Lucy S. Oswald
arXiv · UPDATED DAILY