Henize 70

Henize 70 (N70) is a faint^[7] emission nebula^[8] and superbubble^[5] located in the Large Magellanic Cloud in the constellation of Dorado.

Henize 70

Emission nebula
Superbubble
Amateur photograph of Henize 70
Observation data: J2000 epoch
Right ascension	05h 43m 17.5s[1]
Declination	−67° 50′ 48″[1]
Distance	~50,000[2] pc
Apparent dimensions (V)	7′ × 8′[3]
Constellation	Dorado
Physical characteristics
Dimensions	346 × 396 ly[4][a]
Notable features	Superbubble
Designations	Henize 70,[5] N70,[3] LHA 120-N 70,[3][6] DEM L 301, MCELS L-373[6]
See also: Lists of nebulae

Observation history

Henize 70 was first observed in 1950 in a survey of bright planetary nebulae. Based on appearance it was proposed that it might be a supernova remnant.^[7] In 1956, it was added to a catalogue of Hα emission stars and nebulae by Karl Gordon Henize, where it was described as an emission nebula rather than a planetary nebula.^[8]

Origins

ESO image of Henize 70

A paper published in 1978 proposed that the formations of Henize 70 and other emission nebulae could be due to stellar winds.^[9] Later in 1981, a scientific article mentioned a higher likeliness of a supernova explosion forming the nebula instead of stellar winds.^[10] A 2014 study measured that Henize 70 featured high S_II and Hα ratios, indicating that it is not a supernova remnant.^[11]

Henize 70 has spectral line ratios relatively similar to that of supernova remnants due to having similar S_II/Hα line ratios although most supernova remnants have higher N_II/Hα line ratios.^[12]

Notes

1. Using angular dimensions of 7’ × 8’ and a distance of ~170 kly.
   ${\displaystyle d\times \sin {\theta }}$