Hartl-Dengel-Weinberger 3 (HDW 3)

Image Title: Hartl-Dengel-Weinberger 3 (HDW3)

Copyright: Juan Marin Otero

Date image was taken: November 16, 2025

Location: Starfront Observatories, Texas

Data Acquisition Method: Remote Observatory (Commercial)

Description and Details: Hartl–Dengel–Weinberger 3 (usually shortened to HDW 3, catalog names PK 149−09.1 / PNG 149.4−09.2) is a large, very old planetary nebula in the constellation Perseus. It has extremely low surface brightness and is considered highly evolved — the remnant of a star that has long since shed its envelope and left behind a faint, expanding shell.

This object is extremely faint and requires long integration times to get the best out of it. The exposures were as follows:

Antlia Blue Pro: 36×600″(6h) (gain: 0.00) f/8 bin 1×1
Antlia Green Pro: 35×600″(5h 50′) (gain: 0.00) f/8 bin 1×1
Antlia Red Pro: 34×600″(5h 40′) (gain: 0.00) f/8 bin 1×1
Chroma H-alpha 3nm Bandpass 50 mm: 161×1200″(53h 40′) (gain: 100.00) f/8 bin 1×1
Chroma OIII 3nm Bandpass 50 mm: 161×1200″(53h 40′) (gain: 100.00) f/8 bin 1×1

Total : 124h 50min

The equipment used is listed below:
Planewave CDK12.5
Imaging Cameras
ZWO ASI6200MM Pro
Mounts
Astro-Physics 1100GTO-AE
Filters
Antlia Blue Pro · Antlia Green Pro · Antlia Luminance Pro · Antlia Red Pro · Chroma H-alpha 3nm Bandpass 50 mm · Chroma OIII 3nm Bandpass 50 mm · Chroma SII 3nm Bandpass 50 mm
Accessories
Optec Sagitta Off-Axis Guider · Pegasus Astro Ultimate Powerbox 3 · ZWO EFW 7 x 2″

Name: Juan Marin Otero