NN Serpentis is a binary system with an eclipsing post-common envelope located approximately 1670 light-years distant. It’s a White Dwarf, by the way. It was most likely a star similar to our own, the Sun, before it had reached the end of its existence and depleted all of its fuel. A white dwarf and a red dwarf are eclipsing in the system. Between being a Main Sequence star and its current state, it would have risen in size and then shed its material as a Planetary Nebula, which has subsequently dispersed. Every 0.13 days, the two stars orbit each other. It would not have enough mass to go supernova.
NN Serpentis is not part of the Serpens constellation shape, but it is within its boundaries. It is 1701.78 light years away from Earth. The white dwarf’s location in the night sky is determined by the Right Ascension (R.A.) and Declination (Dec.), which are equal to Longitude and Latitude on Earth.
Planets discovered using timing complement those discovered through radial velocity and transit surveys since they are easier to find the larger their orbits are. The existence of planets around evolved stars raises intriguing questions about whether the planets are primordial and survived the host binary’s evolution, or whether they formed from material ejected during the course of stellar evolution, and may also impose unusual constraints on the binary’s evolution.
Planetary system
The discovery of hundreds of planets orbiting stars other than the Sun has awakened scientists to the potential impact of planets in a wide range of situations. Among these are the remarkable Kepler discoveries of planets crossing across both stars in the closer binary systems they orbit.
Several teams have hypothesized the existence of a planetary system around NN Ser. All of these groups rely on the fact that Earth is in the same plane as the NN Serpentis binary star system, allowing humans to view the larger red dwarf eclipse the smaller white dwarf every 0.13 days. Astronomers can then utilize these frequent eclipses to detect a pattern of minor but major anomalies in star orbits that could be attributable to the presence and gravitational effect of circumbinary planets.
NN Serpentis d is a gas giant exoplanet in the habitable zone of an O-type star. It has a mass of 2.3 Jupiters, takes 7.9 years to complete one orbit around its star, and is 3.43 AU away from it. It was discovered in 2010 and was announced at the time. Chen (2009) used these “eclipse timing variations” to propose an orbital period ranging from 30 to 285 years and a minimum mass ranging from 0.0043 to 0.18 Solar masses.
Qian predicted a minimum mass of 10.7 Jupiter masses and an orbital period of 7.56 years for this planet, which is most likely positioned at 3.29 Astronomical Units in late 2009. This has since been disproven by additional measurements of the binary stars’ eclipse timings.
The post-main sequence eclipsing binary NN Serpentis has recently been identified as a possible home for at least two huge planetary companions. In that paper, the authors proposed two alternative architectures that fit the eclipsing binary observations with nearly comparable precision.
In late 2009 and early 2010, academics from the United Kingdom (Universities of Warwick and Sheffield), Germany, Chile (Universidad de Valparaiso), and the United States collaborated (University of Texas at Austin). It has been proposed that the differences in eclipse time are caused by two gas giant planets. The more massive gas giant orbits the twin star every 15.5 years and is about 6 times the mass of Jupiter; the other orbits every 7.75 years and is about 1.6 times the mass of Jupiter.
