Visualization of J0247-25

This animation shows the main features of the recently discovered binary system J0247-25. The larger star is an SX Phe-type star that pulsates in multiple modes with periods near 40 minutes. The smaller star, J0247-25B, is the remnant of a star that has been stripped of its outer layers to reveal a shell-hydrogen burning core. This star pulsates in at least 3 modes with periods near 5 minutes.


The relative sizes of the stars are correctly shown relative to their separation. The timescales for the pulsations on both stars are correct relative to the orbital period of the binary, which is about 16 hours. We do not currently known the exact pulsation modes of the stars, so the pattern of the pulsations on the stars are arbitrary. The constrast of the image has been set to show the pulsations clearly, in reality the size of the variations is much more subtle that shown here.

New! Listen to J0247-25!

Click the Play button below to here the pulsation signal from J0247-25 scaled up by 19 octaves!

What am I hearing?

The pulsation signal from J0247-25 has been scaled up in frequency into the audio range so that we can hear it. The background "hum" is caused by the low frequency pulsations from J0247-25A. The high pitch "dialling tone" is caused by the high frequency pulsations from J0247-25B being interupted once per orbit when the star is eclipsed.

Images for press release

Artist's impression of the eclipsing, pulsating binary star J0247-25 (Credit: Keele University) (Click for high resolution version).

Dr Pierre Maxted (
Astrophysics Group, Dept. Physics and Astronomy
Keele University, Staffordshire, ST5 5BG