B161 & LDN 1121

B161 and LDN 1121 in Cepheus, imaged from a light polluted urban sky

B161 & LDN 1121

Barnard 161 & LDN 1121 • Dark nebula complex • Cepheus • ~1500 light-years from Earth


🗓️
June – July 2024

Overview

This image shows B161 and LDN 1121, two dense dark nebulae embedded within the much larger emission nebula IC 1396. The frame captures just over 10% of IC 1396, focusing on a region where glowing hydrogen, oxygen, and sulphur gas overlap. The inky dark structures are cold clouds of dust that block the light from background stars, creating high contrast silhouettes that are particularly striking in narrowband astrophotography.

Background

IC 1396 is a very photogenic region of the sky. It’s a large object, so well-suited to wide-field telescopes. In fact, I captured it a few years back using my Askar FRA400 telescope. If you have a longer focal length to play with, like my Askar 130PHQ‘s 1000mm, then you can really zoom in to see get those details. Most people are drawn to the the Elephant’s Trunk Nebula, and I photographed that back in October 2022. There’s a lot more to see in this region of space though, and I decided to return to it in order to snap the lesser-known region next to the Elephant’s Trunk, known as B161 and LDN 1121. Here’s my wide-field view of IC 1396, and the box shows the area covered by my latest image:

Askar FRA400 photo of nebula IC1396, with the region containing B161 and LDN 11121 highlighted

Specifically, B161 and LDN 1121 are these areas:

B161 and LDN 1121's location labelled

Just out of curiosity, I cropped the old Askar FRA400 view to match my latest attempt with the Askar 130PHQ. Of course it’s not a fair comparison as the two were processed differently, and have different integration times, but use the slider view below and you’ll get an idea of the benefits that a bigger telescope can give. The 130PHQ view is certainly sharper and has more detail, but I’m impressed with how well the FRA400 holds up even when cropped in so much. The differences are definitely more apparent when viewed on a big screen!

B161 and LDN 1121 in Cepheus, imaged from a light polluted urban sky
Framed astrophoto taken from a light-polluted city, available to buy as a fine art print

Close-ups

  • Close-up view of the nebula's central region
  • Close-up view showing a darker area and surrounding nebulosity
  • Close-up viewing showing blue and orange nebulosity
  • Close-up view showing intricate detail

Imaging details

Date

2 June – 8 July 2024 (five weeks)

Location

Bristol, UK (Bortle 8)

Telescope

Askar 130PHQ Flatfield Astrograph

Camera

ZWO ASI 2600MC Pro

Mount

Sky-Watcher EQ6-R Pro

Guiding

WO 50mm + ZWO ASI 120MM Mini

Control

ASIAIR Plus

Software

PixInsight, Lightroom

Image by

Lee Pullen

Filter

Channels

Exposure

Optolong L-Quad Enhance

RGB (stars)

15 × 2-minutes (30 minutes)

Optolong L-Ultimate

Hα / OIII

240 × 5-minutes (20 hours)

Askar Colour Magic ED

SII / OIII

240 × 5-minutes (20 hours)

41 hours

Imaging details

Date
2 June – 8 July 2024 (five weeks)

Location
Bristol, UK (Bortle 8)

Telescope
Askar 130PHQ Flatfield Astrograph

Camera
ZWO ASI 2600MC Pro

Mount
Sky-Watcher EQ6-R Pro

Guiding
WO 50mm + ZWO ASI 120MM Mini

Control
ASIAIR Plus

Software
PixInsight, Lightroom

Image by
Lee Pullen

Filters

Optolong L-Quad Enhance
RGB (stars)
15 × 2-minutes (30 minutes)

Optolong L-Ultimate
Hα / OIII
240 × 5-minutes (20 hours)

Askar Colour Magic E2
SII / OIII
240 × 5-minutes (20 hours)

Total exposure: 40.5 hours

Processing walkthrough

For the main bulk of data — that’s 20 hours of Optolong L-Ultimate and 20 hours of Askar D2 — I used 300-second subframes. This is simply to produce lower numbers of files in order to delay my harddrive from filling up! For the RGB data (Optolong L-Quad Enhance) I used 120-second subframes. This is because I only needed a little bit of data for the stars, so a few short subframes was sufficient.

As for the processing itself, I wanted to make this one more vibrant than usual as a bit of an experiment to see the range of colours I could obtain. I might return to the data one day and tone it down a bit, but I kinda like having something so dazzling in my gallery.

Example astrophotography image promoting one-to-one online astrophotography masterclasses

Example source data

Here are example single subframes and freshly integrated stacks, just with simple stretches applied.

Seestar S50 image

Here’s an image of this region of space taken using my Seestar S50 telescope. The nebula’s shape is just about becoming apparent after 88 minutes of integration time.






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