DouLi Hat (Rice Hat) Nebula (Sh2-224) and Sh2-223 in Auriga (DoubleStarPhotography)

DouLi Hat (Rice Hat) Nebula (Sh2-224) and Sh2-223 in Auriga

Sh2-224, also referred to as the DouLi Hat or Rice Hat Nebula, is a very faint and intricate supernova remnant approxiamtey 14,700 light-years away located in the constellation of Auriga.

I went into this shot thinking I would becapturing two supernove remnants (Sh2-223 & Sh2-224), only to learn afterwards that Sh2-223 was once considered to be a supernova remnant candidate, but is now considered to be just a large HIII region.

This object requires significant integration time to do it justice. Single 5 min subs BARELY showed any hint of signal for either of these nebula. I started this project with a solid 8hrs of subs the first night and found that only a very noisy and ghostly sketch of these objects was revealed once stacked. Not to be deterred, I added an additional 12 hours of data over two subsequent nights which helped improve the signal to noise ratio to a degree, but it is still quite noisy. This object IMHO really calls for 3 or 4 times this amount of data to properly reveal it's faint yet intricate beauty.

This is now my longest integration to date (20hrs), and I'm thinking I'm going to be in the double digits for many of my future captures. I think that is going to be a requirment from now on more times then not in order to go after the objects I'm eager to see next! ;-)

Original
Final
C

C

Description: Slight revision to brightness and contrast

Uploaded: ...

	Distinct awarded users	Total awarded images
Image of the day
Top picks
Top pick nominations

	Image of the day	Top pick	Top pick nominations	Total submitted
Deep sky
Solar system
Extremely wide field
Star trails
Northern lights
Noctilucent clouds
Landscape

	Image of the day	Top pick	Top pick nominations	Total submitted
Backyard
Traveller
Own remote observatory
Amateur hosting facility
Public amaeteur data
Professional, scientific grade data
Mix of multiple sources
Other
Unknown

Submitted The date and time when you submitted this image for IOTD/TP consideration.	...
Views by Submitters (available since September 19th, 2023) Every image is assigned to 50% of available Submitters. In the event that at least 80% of them don't view the image before its time in the IOTD/TP process expires, it's assigned to the other 50% of Submitters and the process begins anew.
Promotions by Submitters When 3 distinct Submitters promote the image, it moves on to the next stage of the process: evaluation for Top Pick status. This requirement, in addition to anonymization of images and distribution to only a subset of them, prevents biases and ensures that the best images are selected.
Promotions by Reviewers When 3 distinct Reviewers promote the image, it moves on to the next stage of the process: evaluation for IOTD status.
Early dismissal Staff members have a lot of images to inspect on a daily basis, and they can dismiss images if they believe they don't meet the requirements for IOTD/TP selection. If an image is dismissed 5 times, it's removed from the process. This streamlines the process and ensures that any bias present in promotions could be overruled by other staff members.

Status	Advanced success
Started	...
Astrometry.net job	9041271
PixInsight job	XPSEDY9S44LQDX7PERHSSK51QUBI7GYE
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	05h23m23s.44
RA (top/left)	05h34m15s.78
RA (top/right)	05h13m05s.86
RA (bottom/right)	05h12m54s.99
RA (bottom/left)	05h33m15s.30

Dec (center)	+42°14′18″.6
Dec (top/left)	+43°24′23″.2
Dec (top/right)	+43°34′33″.9
Dec (bottom/right)	+41°00′28″.4
Dec (bottom/left)	+40°50′43″.3

Image Index:

Contribution Index (beta):