V1223_SAGITTARII
We propose a model-independent mass and radius measurement of a magnetic White Dwarf (WD) by assessing its surface rotational velocity. This will be achieved with the Doppler shift of the 6.4 keV lines emitted from the WD surface. Subsequently, the WD mass will be calculated using the measured radius and the previously determined plasma maximum temperature. Our target is the magnetic cataclysmic variable V1223 Sgr, a former candidate for the PV target, as all necessary parameters have already been measured. This measurement aims to differentiate between the mass-radius relation of strongly-magnetic WDs and the standard relation. To achieve this, we estimate that a total exposure time of 192 ks is required, spread across all one-eighth WD spin phases each of which we will analyze.
obsid = 201082010 / Unique Observation/Sequence Number
object = V1223_SAGITTARII / Object name
pi_name = HAYASHI TAKAYUKI / Proposal Principal Investigator Name
ra = 283.759614972565 / Right Ascension (Pointing Position) (deg)
dec = -31.1637147606918 / Declination (Pointing Position) (deg)
roll_angle = 264.607757892044 / Roll Angle (deg)
start_time = 2025-10-04T00:55:04 / Start Time of the Observation
stop_time = 2025-10-08T08:53:04 / Stop Time of the Observation
exposure = 236532.93415 / Effective Total Observation Exposure (s)
public_date= 2026-10-23 / Public Date