Spaghetti Nebula (Simeis 147, Sh 2-240)
History
The emission nebula Simeis 147 (Sim 147, or also S 147) was discovered in the early 1950s by the Russian astronomers Grigory Abramovich Shajn and Vera Fedorovna Gaze at the Simeis Observatory on the Crimean Peninsula. In their «Gaze-Shajn Catalog of Emission Nebulae» published in 1955 they listed nebulae 74 with the notes: «The system of fine-filamentary, arcuate nebulae forms an almost closed circle of ~3°. Includes S147, S149, S151, S155.» And nebula 77 with the notes: «The most prominent part of the filamentary nebula system S147.» [402]
In the second half of the 1950s the American astronomer Stewart Sharpless came across this nebula while searching the photo plates of the «Palomar Observatory Sky Survey» for H-II regions. He listed it as Sh 2-240 and published in in 1959 together with a total of 313 H-II regions in a catalog. He gave a size of 180 arcminutes in diameter, circular form, filamentary structure, medium brightness and noted: «Peculiar filamentary nebula. Radio source.» [310]
Physical Properties
Simeis 147 (SNR G180.0-01.7) is is an optically faint shell-type supernova remnant (SNR) located in the direction of the Galactic anticenter. Its age is estimated to ~40'000 years and one of the oldest SNRs with well-defined shell structure. The supernova left behind the runaway 143 ms pulsar PSR J0538+2817, which has a traverse velocity of ~400 km/s. The distance has been determined as ~1.47 kpc. [259]
| Bezeichnungen | Simeis 147, Sh 2-240, SNR G180.0-01.7, LBN 822, LBN 180.05-01.66 |
| RA (J2000.0) | 05h 39m 00s |
| Dec (J2000.0) | +27° 49' 60" |
Finder Chart
The supernova remnant Simeis 147 is located in the constellation Taurus just south of Auriga and crossing its border. It is right in the middle between the 1.6 mag star β Tauri (Elnath) and 4.5 mag star 136 Tauri. The best observation time is August to April.
