The Orbital Period vs. Absolute Magnitude Relationship of Intermediate Polars: Implications for Low States and Outbursts

Abstract

Recent advances in time-domain astronomy have led to fresh observational insights into intermediate polars, a subtype of magnetic cataclysmic variables generally accreting via a partial accretion disc. These new discoveries include detections of superhumps, low states, and outbursts. However, these studies have largely relied on relative photometry. Here we tabulate the absolute G magnitudes of confirmed intermediate polars, plot them against their orbital periods, and compare the results to similar studies of dwarf novae during quiescence and in outburst. This exercise suggests the presence of two distinct luminosity classes of intermediate polars, with practical and physical implications for the studies of low states and outbursts. In particular, we point out that two of the optically luminous systems showing short outbursts are also seen to exhibit superhumps, suggesting that they may be caused by the same underlying mechanism.

9 pages including 4 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society

References in corpus (14)

• The Gaia mission
• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• The XMM-Newton serendipitous survey IX. The fourth XMM-Newton serendipitous source catalogue
• The first XMM-Newton slew survey catalogue: XMMSL1
• Constraints on the space density of intermediate polars from the Swift-BAT survey
• Measuring the masses of magnetic white dwarfs: A NuSTAR Legacy Survey
• Localised thermonuclear bursts from accreting magnetic white dwarfs
• TESS light curves of cataclysmic variables I -- Unknown periods in long-known stars
• Follow-up Studies of Five Cataclysmic Variable Candidates Discovered by LAMOST
• Radio and optical observations of the possible AE Aqr twin, LAMOST J024048.51+195226.9
• Rapid bursts of magnetically gated accretion in the intermediate polar V1025 Cen
• Hitting a New Low: The Unique 28 h Cessation of Accretion in the TESS Light Curve of YY Dra (DO Dra)
• Magnetically-gated accretion model: application to short bursts in the intermediate polar V1223 Sgr

Cited by in corpus (5)

• A Time-Dependent Spectral Analysis of $\gamma$ Cassiopeiae
• The Rise of Nova V1674 Herculis
• SRGe J194401.8+284452 -- an X-ray Cataclysmic Variable in the Field of the Gamma-Ray Source 4FGL J1943.9+2841
• XMM-Newton and NuSTAR discovery of a likely IP candidate XMMU J173029.8-330920 in the Galactic Disk
• Confirmation of SRGt 062340.2-265751 as a nova-like cataclysmic variable with a possible magnetic nature