SNR G070.0-21.5: A Supernova Remnant in Pegasus Constellation

 The Supernova Remnant (SNR) G070.0-21.5, discovered in 2002, is an astronomical marvel nestled in the Pegasus constellation. Located approximately 3,250 light-years away, it was identified by a team of Greek astronomers who noticed distinctive optical filaments that indicated the presence of one or more SNRs. The remnant holds a unique position in the halo of the Milky Way, far removed from the galactic plane.

With an estimated age of around 90,000 ± 10,000 years, SNR G070.0-21.5 is a colossal and relatively faint SNR in our galaxy. In 2018, a rapidly moving white dwarf named D6-2 was discovered in its vicinity, travelling at an impressive speed of 1,200 km/sec.

The optical structure of SNR G070.0-21.5 has shown signs of shock-induced heating, suggesting its large scale. Its filaments are noticeably straighter compared to those observed in younger SNRs, such as the Cygnus Loop. The location of D6-2, traced back 90,000 years, aligns with the center of SNR G070.0-21.5, indicating that the remnant might be the aftermath of a type Ia supernova. The progenitor of this event was likely a binary system of two white dwarfs, with one surviving the explosion and being ejected at high speed.

In 2015, researchers observed hydrogen emission in the form of Hα from SNR G070.0-21.5, which spans an area of approximately 4°.0 × 5°.5 degrees - eight to eleven times the size of the full Moon. This hydrogen emission coincides with weak X-ray emission detected in the remnant's northern part, as observed with ROSAT.

Accompanying this text is a composite optical image of SNR G070.0-21.5, captured using a small amateur telescope. The image was created using a combination of broadband filters (RGB) and narrow band filters that focused on the emission of ionised oxygen ([O III]) and ionised hydrogen (Hα). 

Image Credit goes to Bray Falls @astrobin.