Outreach
Sharing the wonders of the cosmos with the public is a vital part of the scientific journey.
Micronovae are thermonuclear explosions confined to small regions near the magnetic poles of accreting white dwarfs. Discovered in optical timing data from NASA’s TESS mission, each burst releases about a millionth of the energy of a classical nova.
We believe the white dwarf’s magnetic field acts as a funnel, confining fresh material onto the stellar poles (somewhat like the aurorae on Earth). This magnetic bottleneck lets the pressure and temperature needed for ignition build up much faster, so far less material is needed than for a global classical nova.
Because the bursts fade within a few hours they are easy to miss, which explains why they went undetected for decades. Read the Nature paper.
An animation of the brightness variations of MV Lyrae observed by Kepler. Gas piles up at the magnetospheric boundary and periodically overcomes the magnetic barrier, producing accretion bursts every two hours.
A three-month time-lapse of the globular cluster M4 captured by NASA’s K2 mission. The pulsating points are old RR Lyrae variables, cycling through temperature and opacity changes.
Accretion discs emit light that flickers on timescales from milliseconds to days. By turning these light curves into audio and shifting their frequencies into the range of human hearing, we can “listen” to how cosmic engines grow.
A composite image of the Crab Nebula supernova remnant, taken with the MAIA camera on the 1.2-metre Mercator Telescope on La Palma and combining r-, g- and u-band exposures.