“They look up in awe, but they don’t realize—they are more fragile than the dust from which I breathe. And still, we shine.”
NGC281 – Pacman Nebula – SHO (Hubble Palette)
Description
NGC 281 is a bright emission nebula and part of an H II region in the northern constellation of Cassiopeia and is part of the Milky Way’s Perseus Spiral Arm. This 20×30 arcmin sized nebulosity is also associated with open cluster IC 1590, several Bok globules and the multiple stars.
NGC 281 is also known as the Pacman Nebula for its resemblance to the video game character.
Edward Emerson Barnard discovered the nebula in August 1883, describing it as “a large faint nebula, very diffuse”.
Image Information
| Object(s) Catalog No. | NGC281 |
| Object Type | Emission Nebula |
| Constellation | Cassiopeia |
| Size | 35′ |
| Magnitude | 7.4 |
| Distance | 5545.4 Light Years |
Conditions
| Date | September 30, 2024 |
| Astronomical Dusk: | 21h |
| Moon Age | 28 days |
| Moon Phase | [Waning Crescent] |
| Temperature | Approximately 16 degree Celsius |
| Transparency | Above Average |
| Seeing | Above Average |
| Wind | 9 km/h |
| Humidity | 76 % |
| Sky ADU | n/a |
| Sky Flux (e/min) | n/a |
Equipment
Software
| Mount | CGEM – OnStep Retrofit |
| Imaging Scope | Modified Orion ED80T CF |
| Guiding Scope | APM 60mm Image Maste |
| Imaging Camera | ASI294M Pro |
| Guiding Camera | QHY5L-II-M |
| Additional Optics | SharpStar Field Flattener – 2.5″ |
| Filters | Baader SHO filters (7, 8, 8.5nm) |
| Acquisition | N.I.N.A. |
| Auto-Guiding | PHD2 |
| Processing | Pixinsight |
Acquisition Details
Number of files acquired
– 36 (Kept 35) Lights
– 90 Flats
Total Integration Time: 4.5 hours
Start Time – Stop Time: [20h14- 1h41]
| Filters | L | R | G | B | Ha | OII | SII |
| Camera Temperature | -10 | -10 | -10 | ||||
| Binning | 1 | 1 | 1 | ||||
| Number of sub-frames | 18 | 9 | 9 | ||||
| Sub-frames duration (sec) | 300 | 600 | 600 | ||||
| Number of good sub-frames | 18 | 8 | 9 | ||||
| Number of Flats | 30 | 30 | 30 | ||||
| Flats Duration (sec) | 20 | 20 | 20 | ||||
| Number of Darks | Master | Master | Master | ||||
| Number of Flat Darks | Master | Master | Master | ||||
| Darks Duration (sec) | 300 | 600 | 600 | ||||
| Number of Bias | 0 | 0 | 0 |
Auto-Focuser Position: 2637
Autoguiding Average 0.55″
Acquisition Notes
Nice transparency which translated in less light pollution being reflected.
Processing Notes
Getting easier to process with new AI tools (e.g. GraXpert, StarNet, BlurXterminator)
I am starting to love my new ASI294MM Pro.
Upgraded my motherboard and CPU and added storage to handle the larger images.