SH2-129 Flying Bat & OU-4 Giant Squid Nebulae

Fun facts

SH2-129, sometimes referred to as the “Flying Bat” nebula, is a relatively faint emission nebula in Cepheus, a neighbor of the larger and more often imaged IC 1396 Elephant Trunk.  This region is characterized by Ha emission as well as a small, mixed emission and reflection nebula (vdB 140).  What is most remarkable about this region is a recent discovery, made in 2011 by Nicolas Outters, called the “Squid Nebula” due to its shape, but more officially called Ou4.  This region is characterized by a very faint OIII emission that has a bipolar shape reminiscent of a planetary nebula, seen as the teal-colored region just to the left of center.  Although it was originally thought to perhaps represent a planetary nebula derived from an unknown, dying star, more recent evidence suggests that Ou4 is located within SH2-129 itself and is a bipolar outflow emitting in the OIII spectrum, moving at the same rate as SH2-129, and possibly emanating from a triple star system located in the center of Ou4 (HR8119, visible above as the bright star in the center of the Squid).  Though apparently completely surrounded by the reddish hydrogen emission region Sh2-129, the true distance and nature of the Squid Nebula have been difficult to determine. Still, a more recent investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away.  The truly giant Squid Nebula would physically be nearly 50 light-years across.

Other Catalog Designations: SH2-129 Flying Bat Nebula, Ou4 Squid Nebula

Subtype: HII region
Distance from Earth: 2300 light years
Size: 50 light years
Apparent Size: 2°20’

Constellation: Cepheus

{Target information derived from: http://www.starrywonders.com/sh2-129small.html , https://apod.nasa.gov/apod/ap201007.html , and Stellarium }

Capture & Processing Notes

With the beginning of visibility of nebulae, I’ve continued my obsession (started in June 2023) of imaging the SH2-129 Flying Bat and OU-4 Giant Squid Nebulae. Since I was imaging from HCH, Colorado Springs, I decided to capture more data with the OIII filter to supplement the data captured last year on the OU-4 Giant Squid Nebula (the blue region of the image).

Used the data in conjunction with the other data I’ve captured on SH2-129/OU-4 listed below

Composite image’s session sequence plans:

Image was created by registering:

• SH2-129 Flying Bat Combine v2 – RGBHOO (created 10Jan2024)
• SH2-129 4sessionLeX – 23Jun-16Sep (lpg-cbg and StarCal)
• SH2-129 Flying Bat – ASI2400SC with OIII filter – 12&17May2024
• SH2-129 Flying Bat – ASI2400SC with OIII filter – 26May2024

RGBHOO: RGBHOO image, created from the four sessions captured in 23Jun-16Sep2023 using the RGB combine tool to create an RGBHOO image (used the .fits files created on 10Jan2024).  Four sessions captured with the LeX filter were combined using Ha-OIII Color, Ha-OIII extract Ha, and Ha-OIII extract OIII.  The two sessions 15-16Jul2023 were used as the second OIII channel in the RGBHOO image. Four sessions combined to create the RGB with Ha-OIII Color, Ha with HaOIII extract Ha, OIII with HaOIII extract OIII APP algorithms

• Sequence #1 (23Jun2023): Gain: 300, Temp: -0°C, offset=NotSet. 38x10min.  Captured 23Jun2023, 2140MDT – 23Jun2023, 0428MDT.  Total exposure time: 6:20hrs. (HCHASI2400#1SCLeX)
• Sequence #2 (1Jul2023): Gain: 300, Temp: -0°C, offset=NotSet. 21x10min.  Captured 1Jul2023, 2155MDT – 2Jul2023, 0444MDT (with gap 0226-0333MDT), deleted first and last image too much light.  Total exposure time: 3:10hrs. (HCHASI2400#1SCLeX)
• Sequence #3 (2Jul2023): Gain: 300, Temp: -0°C, offset=NotSet. 31x10min.  Captured 2Jul2023, 2210MDT – 3Jul2023, 0436MDT (deleted last image).  Total exposure time: 5:10hrs. (HCHASI2400#1SCLeX)
• Sequence #4 (16Sep2023): Gain: 300, Temp: -0°C, offset=30; 31x10min.  Captured 16 Sep2023 (16Sep2023, 2107MDT – 0301MDT).  Total exposure time: 5:10hrs.

Two sessions of OIII, using OIII Color algorithm

• Sequence #1 (15Jul2023): Gain: 300, Temp: -0°C, offset=NotSet. 24x10min.  Captured 15Jul2023, 2258MDT – 16Jul2023, 0440MDT.  Total exposure time: 5:10hrs. (HCHASI2400#1SCOIII)
• Sequence #2 (16Jul2023): Gain: 300, Temp: -0°C, offset=NotSet. 23x10min.  Captured 16Jul2023, 2209MDT – 17Jul2023, 0411MDT.  Total exposure time: 3:50hrs. (HCHASI2400#1SCOIII)

RGB: Four LeX sessions combined to create the RGB with Ha-OIII Color.  Used the Star Calibration Tool to create a correctly colored star field (rather than the predominant red that is in the LeX version.

• Sequence #1 (23Jun2023): Gain: 300, Temp: -0°C, offset=NotSet. 38x10min.  Captured 23Jun2023, 2140MDT – 23Jun2023, 0428MDT.  Total exposure time: 6:20hrs. (HCHASI2400#1SCLeX)
• Sequence #2 (1Jul2023): Gain: 300, Temp: -0°C, offset=NotSet. 21x10min.  Captured 1Jul2023, 2155MDT – 2Jul2023, 0444MDT (with gap 0226-0333MDT), deleted first and last image too much light.  Total exposure time: 3:10hrs. (HCHASI2400#1SCLeX)
• Sequence #3 (2Jul2023): Gain: 300, Temp: -0°C, offset=NotSet. 31x10min.  Captured 2Jul2023, 2210MDT – 3Jul2023, 0436MDT (deleted last image).  Total exposure time: 5:10hrs. (HCHASI2400#1SCLeX)
• Sequence #4 (16Sep2023): Gain: 300, Temp: -0°C, offset=30; 31x10min.  Captured 16 Sep2023 (16Sep2023, 2107MDT – 0301MDT).  Total exposure time: 5:10hrs.

OIII: Two separate images (one image with data from 12&17May2024 stacked together; one image with data gathered on 26May2024 were registered, captured with the OIII filter. 

• Sequence #1 (12May2024): Gain: 300, Temp: -0°C, offset=30. 37x5min.  Captured 13May2024, 0038MDT – 0408MDT.  Total exposure time: 3:05hrs
• Sequence #2 (17May2024): Gain: 300, Temp: -0°C, offset=30. 55xmin.  Captured 17May2024, 2340MDT – 18May2024, 0439MDT.  Total exposure time: 4:35hrs

• Sequence Plan (26May2024): Gain: 300, Temp: -0°C, offset=30. 19x10min.  Captured 27May2024, 0040MDT – 0429MDT.  Total exposure time: 3:10hrs (ASI2400-SC-OIII)

Capture: RGB: 18 & 23 June, 1 & 2 July; 16 Sep 2023, Total: 19:50 hours. OIII: 12, 17 & 26 May 2024, Total = 10:50 hours. Total exposure time: 30:40hrs

Shooting location: All data gathered from HCH, Colorado Springs, Colorado

Processing summary: Captured with SGP. Stacked and registered in APP. Star removal with Starnet++. Processed in LR/PS using Nico Carver’s technique of colorizing the OIII layer and blending it into the main image.

Equipment

Polar alignment: QHYCCD camera (controlled by Polemaster)
Imaging stream: (Southern Cross) Askar FRA600 on Rainbow Astro RC-135E, ZWO ASI2400MC#1 camera, Filter: Optolong LeXtreme (RGB) or Askar OIII 3nm filter (OIII)
Mount: Rainbow Astro RC-135E (controlled by iHubo ASCOM driver)
Autoguider: Orion 60mm Multi-Use Guide Scope, Orion StarShoot AutoGuider Pro Mono Astrophotography Camera (controlled by PHD2)
Equipment controlled by HP Probook (DSO CTRL 1) running Sequence Generator Pro v3.3.0.1305