No Survivors Left:

[beecee]

https://phys.org/news/2018-08-kepler-supernova-explosion-survivors-left.html

After the Kepler supernova explosion, no survivors were left behind:

A new study argues that the explosion that Johannes Kepler observed in 1604 was caused by a merger of two stellar residues.

The Kepler supernova, of which only the supernova remnant remains, took place in the constellation of Ophiuchus, in the plane of the Milky Way, 16,300 light years from the sun. An international team led by the researcher Pilar Ruiz Lapuente (UB-IECC y CSIC), in which IAC researcher Jonay González Hernández participated, has tried to find the possible surviving star of the binary system in which the explosion took place.

In these systems, when at least one of the stars (with the highest mass) reaches the end of its life and becomes a white dwarf (WD), the other can begin to transfer matter up to a certain mass limit (equivalent to 1,44 solar masses, the so-called "Chandrasekhar limit"). This process leads to the central ignition of carbon in the white dwarf, producing an explosion that can multiply 100,000 times its original brightness. This phenomenon, brief and violent, is known as a supernova. Sometimes, these can be observed with the naked eye from Earth, as in the case of the Kepler supernova (SN 1604), observed and identified by the German astronomer Johannes Kepler in 1604.

Read more at: https://phys.org/news/2018-08-kepler-supernova-explosion-survivors-left.html#jCp

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the paper:

http://iopscience.iop.org/article/10.3847/1538-4357/aac9c4/meta

No Surviving Companion in Kepler's Supernova:

Abstract

We have surveyed Kepler's supernova remnant in search of the companion star of the explosion. We have gone as deep as 2.6 L ? in all stars within 20% of the radius of the remnant. We use FLAMES at the VLT-UT2 telescope to obtain high-resolution spectra of the stellar candidates selected from Hubble Space Telescope (HST) images. The resulting set of stellar parameters suggests that these stars come from a rather ordinary mixture of field stars (mostly giants). A few of the stars seem to have low [Fe/H] (<?1) and they are consistent with being metal-poor giants. The radial velocities and rotational velocities vrot sin i are very well determined. There are no fast rotating stars because v rot sin i?<?20 km s?1 for all the candidates. The radial velocities from the spectra and the proper motions determined from HST images are compatible with those expected from the Besan?on model of the Galaxy. The strong limits placed on luminosity suggest that this supernova could have arisen either from the core-degenerate scenario or from the double-degenerate scenario.