National Aeronautics and Space Administration

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
V1025 Cen
V1033 Cas
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

Observations Wanted to Confirm Probable and Possible IPs

Systems needing X-ray confirmation of the spinperiod

• 1RXS J015317.9+744641: 1974 s Spin period claimed from ROSAT data; RXTE observation failed to confirm the spin period.
• Swift J0503.7-2819
• Swift J0535.2+2830: X-ray confirmation of the 1523 s optical spin period is needed.
• V902 Mon: It is X-ray faint and does not appear to be modulated on the optically detected spin period, but that is probably because of the edge-on viewing geometry where the partial disk prevents us from seeing the white dwarf directly.
• Swift J0939.7-3224: it has a known orbital period from optical spectroscopy and a candidate optical photometric period of 2670 s, never confirmed in X-rays.
• VZ Sex: While the X-ray confirmation of the spin period is claimed, it is based on data of low statistical quality. The highest peak in the X-ray periodogram is at 20.3 min, while the periodogram of the optical data has a peak at 36 min (2162 s). More optical data are also needed.
• RZ Leo: this is a WZ Sge-type dwarf nova with 220 s UV period. An independent confirmation of the period, particularly in X-rays, is highly desirable although potentially very difficult.
• V407 Lup: this is a probable IP based on data taken during the nova eruption. Confirmatory data taken during the accretion dominated phase are highly desirable.
• IGR J18434-0508: It is an INTEGRAL discovered object with an H-alpha emission line and an apparent spin period of 152.49 s seen in the optical. In addition to X-ray confirmation of this period, time-resolved optical spectroscopy to measure the orbital period is crucial.
• ZTF J185139.81+171430.3L It shows a coherent, large-amplitude, 12.37 m pulsation in the optical. Although proposed to be an AR Sco type system, the high X-ray luminosity among other clues suggest it is likely to be an IP. Further optical observations as well as deeper X-ray observations are needed.
• 2PBC J1911.4+1412: This is a hard X-ray luminous object with a CV-like optical spectrum and a 746 s optical photometric period. X-ray confirmation of the spin period, and time resolved optical spectroscopy to determine the orbital period, are needed.
• Swift J2116.5+5336: This is an eclipsing CV associated with an unpublished BAT source. The eclipse light curve shows the presence of a disk. It may be an IP, though no spin period has been reported so far.

Systems needing dedicated optical observations

• 1RXS J015317.9+744641: In addition to X-ray data, more optical data are desirable.
• Swift J0525.6+2416: 20 hrs of optical photometry failed to reveal the X-ray detected spin period of 226.28 s or any other period, with a strong upper limit. Optical spectroscopy to detect the orbital period is needed, as well as another attempt at optical photometry.
• Swift J0535.2+2830: In addition to the X-ray confirmation of the spin, time-resolved spectroscopy is needed to measure the orbital period.
• Swift J061223.0+701243.9: There are no published optical studies beyond a description of the HET spectrum in an ATel.
• Swift J0746.2-1611: There is a hint of 2300 s X-ray period in a 9.4 hr binary, and the system was observed with XMM in high and low flux states. An independent confirmation of the potential spin period is highly desirable.
• 1RXS J080114.6-462324: It a 1308 s period seen in X-rays and the optical. Longer runs of optical photometry to beat down on alias patterns, and time resolved spectroscopy in search of the orbital period, are desirable.
• Swift J0820.6-2805: It has a possible 2485 s optical period. Longer runs of optical photometry, as well as time-resolved optical spectroscopy, are desirable.
• Swift J0958.0-4208: It has an X-ray spin period of 296.22 s, but there appears to be no published optical study beyond the identification spectrum.
• IGR J12123-5802: It is a hard X-ray detected CV. XMM observation failed to show a spin modulation. There appears to be no published optical study beyond the identification spectrum.
• IGR J14091-6108: It has a clear 576.3 s X-ray spin period. Optical photometry and time-resolved optical spectroscopy are required.
• IGR J14257-6117: It has no time-resolved optical observations in the literature, and its IP credential is based on one XMM observation.
• SDSS J144659.95+025330.3: It has a candidate spin period of 48.7 min from short XMM observations and from a limited run of optical photometry. Longer observations are needed to confirm the IP status.
• IGR J16167-4957: This is a hard X-ray bright CV but no spin period has been detected so far. A timing analysis of the existing XMM data as well as new time-resolved photometry, particularly with blue (or even U band) filters, may be worthwhile.
• 1RXS J163100.5+695000: It is an optically faint CV with a prominent HeII 4686 line. However, there is no published optical time-series photometry, and it was undetected in a 4 ks Swift XRT observation.
• AX J1700.1-4157 has a secure 714.5 s X-ray period, but no optical determination of the spin or orbital periods.
• Suzaku J174035.6-301416: It is an source with an IP-like X-ray spectrum and a 432 s period the Suzaku observation. Nothing is known about the optical counterpart, however.
• SAX J1748.2-2808: This is an X-ray source with a stable 593 s period and an IP-like X-ray spectrum. Optical and/or IR observations of the likely counterpart, seen in Gaia, are needed.
• XMMU J175035.2-293557: It was seen to have a 510 s period in a 2017 XMM observation, but this period was not seen during a 2006 Chandra observation. Secure optical/IR identification and an independent confirmation of the 510 s period are essential.
• IGR J18088-2741: This is an INTEGRAL source with a likely periodic signal in the X-rays with a period of ~854 s. The optical counterpart has a CV-like spectrum with a possible 6.84 hr OGLE periodicity. Detailed optical observations are needed.
• IGR J18293-1213: This is an INTEGRAL source with X-ray eclipses and a CV-like X-ray spectrum. The optical counterpart should be studied, and spin period search should be performed in X-rays and in the optical.
• Swift J201424.9+152930: This is an eclipsing system with a 3.5 h orbital period, in which a 491 s X-ray period is seen. The X-ray spectrum may be atypical for an IP, though, including its apparently modest luminosity. Time-resolved optical spectroscopy and photometry would also be highly useful.