IPs

V455 And
V515 And
AE Aqr
FO Aqr
V349 Aqr
XY Ari
V405 Aur
V647 Aur
HT Cam
MU Cam
DW Cnc
BG CMi
V709 Cas
V1033 Cas
V1025 Cen
TV Col
TX Col
UU Col
V2069 Cyg
V2306 Cyg
DO Dra
PQ Gem
V418 Gem
DQ Her
V1323 Her
V1460 Her
V1674 Her
EX Hya
NY Lup
V2400 Oph
V2731 Oph
V3037 Oph
V598 Peg
GK Per
AO Psc
HZ Pup
V667 Pup
WX Pyx
V1223 Sgr
V4743 Sgr
CC Scl
V1062 Tau
EI UMa
AX J1740.1
AX J1832.3
AX J1853.3
CTCV J2056
CXO J174954
IGR J04571
IGR J08390
IGR J15094
IGR J16500
IGR J16547
IGR J17014
IGR J17195
IGR J18151
IGR J18173
IGR J18308
IGR J19267
LAMOST 0240
PBC J0927.8
PBC J1841.1
RX J1804
RX J2015
RX J2113
RX J2133
RX J2306
Swift J0717
Swift J1839
Swift J2006
Swift J2138

Full Catalog

Related Systems

The Intermediate Polars

Welcome to the Intermediate Polar Home Page, Version 2!

Sixty-four of seventy-one Ironclad or Confirmed IPs are shown above in a P_orb-P_spin diagram (see the list sorted by the P_orb/P_spin ratio). Symbols: Open Square for the diskless system V2400 Oph, Diamonds for the propeller systems AE Aqr and LAMOST J024048.51+195226.9, and Circles for the rest. The vertical dashed lines show the approximate location of the period gap, while diagonal lines are for P_orb=P_spin (solid) and P_orb=10xP_spin (dashed). Also see the note on the accretion modes of IPs.

See the full catalog, Version 2021 of IPs and IP candidates, updated on 2021 December 30.

Update posted on 2026 January 8: I have started a long-overdue process of updating the IP catalog. The first step will be to update the pages for individual IPs and candidates; only when that process is nearly complete, I will embark on compiling a new catalog. In the mean time, there will be disagreements between the 2021 catalog and what the individual IP/candidate pages say, e.g., Swift J0503.7-2819 now classified as "confirmed" but with a spin period different from what I have in the 2021 catalog. The complete list of updates can be found here.