Radio Pulsar / White Dwarf

Radio pulsars and white dwarf stars are formed when stars cave in and die. Both pulsars and white dwarfs are extremely massive and compact: pulsars are 500.000 times heavier than the earth, but only 10 miles in diameter. That means a coffee mug filled with 'pulsar' weighs as much as the entire Mt. Everest! Their density and gravitational pull are gigantic, and stretches space and time in their vicinity. When you look at a radio pulsar passing behind a white dwarf, you can actually see its light slow down as it struggles past the white dwarf.

Shapiro delay is prominent in this plot of time-of-arrival offsets versus orbital phase. Shown are the residuals for the best-fit model that incorporates all Newtonian and general-relativistic radio-pulsar and binary motion characteristics but with the Shapiro delay parameters removed. As the radio pulsar moves behind the white dwarf, pulses are delayed by up to 40 microseconds. PSR J1802-2124 has been timed over the last 2 years with GBT+GASP at L-band.

Legacy Astronomical Images

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Legacy Astronomical Image

PSR J1802-2124

Joeri van Leeuwen (UBC), Bryan Jacoby (NRL), Rob Ferdman (UBC)

Joeri van Leeuwen (UBC), Bryan Jacoby (NRL), Rob Ferdman (UBC)

Green Bank Telescope (GBT)

continuum

L

20 cm

1.4 GHz

RA 18:2:5.000, Dec: -21:24:3.000 (J2000)

0.016667 x 0.016667 degrees

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Galactic Sources Series

Pulsars/Neutron Stars Unit