The star iPTF14hls was discovered in September 2014 by the Intermediate Palomar Transient Factory,[5] and it was first made public in November 2014 by the CRTS survey[6] as CSS141118:092034+504148.

[5] Also, rather than cooling down with time as expected of a Type II-P supernova, the object maintains a near-constant temperature of about 5000–6000 K.[1] Checks of photographs from the past found one from 1954 showing an explosion in the same location.

[19][20] According to Iair Arcavi, this discovery requires refinement of existing explosion scenarios, or the development of a new scenario, that can:[1] One hypothesis involves burning antimatter in a stellar core;[5] this hypothesis holds that massive stars become so hot in their cores that energy is converted into matter and antimatter, causing the star to become extremely unstable, and undergo repeated bright eruptions over periods of years.

[12] Another hypothesis is the pulsational pair-instability supernova, a massive star that may lose about half its mass before a series of violent pulses begins.

[12] Magnetar models can also explain many of the observed features, but give a smooth light curve and may require an evolving magnetic field strength.

The energy conversion efficiency needs to be very high, so it is suggested that a jet (anisotropic emission) from a close companion may be necessary to explain some of the observed data.

[24] This hypothesis suggests common envelope jets supernova (CEJSN) impostors resulting from a neutron star companion.

[3][27] A long-term outflow similar to stellar winds with variable mass-loss rates rather than a sudden outburst like supernovae could fit the data of the light curve not only of iPTF14hls, but also of Eta Carinae.