Henize 70: What is it? (Alex Woronow)

Henize 70: What is it?

Henize 70: What is it?

OTA: CDK24 f/6.55
Camera: QHY 600M
Observatory: Telescope Live (CHI-1)
Date of Capture: Feb-Mar, '23
Date of Processing: Nov, '23

Exposures:
H: 5 x 300 sec
S: 5 x 300
O: 5 x 300
H: 6 x 600 sec
O: 8 x 600
S: 7 x 600
Total Exposure time: 4.75 hours
Image Width: 28.75 arc-minutes

Processing Tools:
1.   Commercial: PixInsight, Topaz (Studio2, Denioise AI), Photo Director 365
2.   Pixinsight Addons: NoiseXTerminator, BlurXTerminator, StarXTerminator
3.   My Scripts: NB_Assistant, AC_Restar, Subframe Weighting Tool (Excel w/ J. Hunt), ColorTweaker

Target Description:
Discovered in 1950, the origin of Henize 70 remains somewhat enigmatic.

When first discovered during a survey of planetary nebulae, it was tagged as a supernova remnant (planetary nebula) and was. However, it was subsequently (1978) described as an emission nebula—a cloud excited by the UV emanating from a hot central star and stellar winds. But in 1981, it was thought to be more likely a supernova again. A 2014 spectrographic analysis of the emissions suggested that it was not a supernova remnant, then Henize conducted another spectrographic analysis and determined it was a supernova…but with unusual spectral properties. (Wikipedia)

Processing Description:
Amazing! The total exposure time per 3nm narrowband filter is only about 1.5 hours, and that was all that was needed: not 8 or 80 hours! Furthermore, the subframes for each filter were split between exposure times of 600s and 300s, and they were aligned, weighted, and integrated without regard for this factor.

Would more exposure time and consistent subframe exposures help? Maybe somewhat, but not very much, even on this rather faint target, at least with a low read noise CMOS camera.

Statistics:
Distance: 60K ly
Apparent Magnitude: 14
Average Surface Magnitude: 27
Pixel Span at Target: 3 x 10^14km

Alex Woronow

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Status	Advanced success
Started	...
Astrometry.net job	8786507
PixInsight job	THK8LEFBVHPV3KWK6FWIC53OJJKQYJTB
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	05h43m23s.155
RA (top/left)	05h40m51s.191
RA (top/right)	05h45m58s.118
RA (bottom/right)	05h45m52s.348
RA (bottom/left)	05h40m49s.590

Dec (center)	-67°50′36″.48
Dec (top/left)	-68°00′27″.10
Dec (top/right)	-67°59′56″.30
Dec (bottom/right)	-67°40′29″.15
Dec (bottom/left)	-67°40′59″.99

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