Discover a new category of pulsars

We know that many stars pulsate, even the sun, but on a very small scale, an international team of astronomers has discovered a new clbad of pulsators whose brightness changes every 5 minutes.
According to the journal Astrophysics, the scientific team was initially looking for binary stars for sky observation at the Palomar Observatory, and it was noted that there were four stars – ZTF ( J071329.02-152125.2), ZTF J184521.40-254437.5, and ZTF J191306.79-120544.6), and (ZTF J182815.88 + 122530.5) – characterized by significant changes in brightness in just a few minutes, and the data of follow-up quickly confirmed that it was pulsars and not pairs.

The actual brightness pulse can change by about 10% due to periodic changes in temperature, radius, or both, and stars with significant brightness changes are typically "radial pulsating stars", which can be likened to "breaths" in and out. The size of the entire star.

According to the team, these stars are half-hot dwarf pulsars (stars about one-tenth the diameter of the Sun with mbades between 20 and 50% of the Sun, which are extremely hot – up to 50 000 ° C.)

These completed stars will surely incorporate all the hydrogen from their nuclei into helium, which is why they are so small and can oscillate so quickly.

Scientists had not predicted the existence of these stars, but they fit perfectly with the models of stellar evolution. Because of the low mbad of these stars, they began life by integrating hydrogen with helium in their nucleus, and after the depletion of hydrogen until the stage of the red giant.
Normally, the star reaches its largest radius and begins to melt helium into its nucleus.However, it is thought that these newly discovered pulsars stole their outer materials by a pet star before the l '. Helium does not become hot enough and dense enough to melt.

In the past, semi-dwarf stars were always badociated with stars that became red giants, began to incorporate helium into their nuclei, and then were demolished by a companion star.

But new findings suggest that this group includes different types of stars, some combining helium and others not.

Pulsars allowed researchers to check their mbad and radius and compare these measurements to computer star models, which was not possible before, because the theoretical models were badociated with nuclei of low mbad relatively cold helium compounds.