A Heart Full of Firsts: Imaging the Heart Nebula

 Our Hearts are Overflowing with Anticipation!

If you ask my wife or me, we will both say the best night of our lives was without question the night our daughter was born. I didn’t think it would be possible to come close to that feeling of pure joy and love. I’m starting to rethink that, as our daughter and son-in-law recently announced they are expecting their first child, our first grandchild. Speaking for my wife and me, our hearts are overflowing with joy and anticipation. As our family prepares nurseries for this new arrival, I would like to dedicate this image of the Heart Nebula—a giant stellar nursery—to my wife, daughter, son-in-law, and expected grandchild.

This image represents another a technical first for me. I used two different dual narrowband filters to capture the data. I used an Optolong L-eXtreme filter to capture hydrogen-alpha (Hα) and doubly ionized oxygen (O III), and an Optolong L-Synergy filter to capture singly ionized sulfur (S II) and O III. This enabled me to process the image in the SHO palette with data from all three emission lines. Since this was my first time processing this combination of data, I found it quite challenging to get a result I was pleased with. After many hours of research, experimentation, and trial and error, I’m pleased with this result. I look forward to the many firsts still to come for our family. Here’s the resulting image:

Image 1: The Heart Nebula (Sh 2-190)

 

Image 1: The Heart Nebula (Sh 2-190) captured from my backyard over two nights in September.

What is the Heart Nebula?

Before getting into the equipment and processing details, it’s worth pausing on what makes The Heart Nebula such a compelling subject. The Heart Nebula is a giant stellar nursery, a vast cloud of gas and dust where new stars are actively forming.

Object type: Emission Nebula with Central Open Star Cluster

The Heart Nebula is a massive emission nebula that is part of a large faint complex of nebulosity known as the W3/W4/W5 Complex. At its center lies the young open cluster Melotte 15. Ultraviolet radiation from its massive stars ionizes the surrounding gas, while powerful stellar winds help sculpt the nebula’s distinctive structure.

Location in the sky: Cassiopeia, within the Perseus arm of the Milky Way Galaxy

The Heart Nebula lies within the Perseus Arm of the Milky Way galaxy in the constellation Cassiopeia. It can be found between the constellations of Cassiopeia and Perseus, next to The Soul Nebula (IC 1848) and not far from The Double Cluster (NGC 884 & NGC 869). This location makes it a great target for late summer and autumn imaging in the Northern Hemisphere. From my location in Western New York, the target is circumpolar; because of its proximity to the North Celestial Pole, it never sets. However, it is best placed, high in the sky in summer and fall.

Distance / size / scale

The Heart Nebula is approximately 7,500 light-years from Earth. It has a radius of about 165 light-years. The Heart Nebula spans about 2 degrees in the night sky, about four times the diameter of the Full Moon.

Visual features

The Heart Nebula exhibits a cavity and shell type structure, which is common for stellar nurseries. The massive stars in the central star cluster power the ionization of the gas and shape the structure with their powerful stellar winds.

• Blue O III nebulosity is strongest within the central region or cavity of the nebula and in the Fish Head Nebula.
• Orange / Yellow Hα and S II emission mark the outer shell of the structure. Faint Hα is also visible in the background of the image.
• Dark Nebulae — concentrated knots of gas and dust that obscure the light behind them — are scattered throughout the image. A superb example is the gill-like structure in the Fish Head Nebula.

The SHO, or Hubble, palette accentuates the contributions of ionized sulfur, hydrogen, and oxygen in a visually striking color scheme.

Why it matters

The Heart Nebula is a stellar nursery that is actively being shaped by the young stars it has already created. The Heart Nebula belongs to the larger W3/W4/W5 complex and forms the brightest part of the W4 Superbubble, also known as the W4 Chimney. This structure may help channel hot gas from the Milky Way’s disk into its halo.

Image 2: Finder Chart for The Heart Nebula (Sh 2-190)

 

Image 2: A finder chart for the Heart Nebula (Sh 2-190).

Prominent Objects in the Field

Object 1: Sharpless 2-190 (Sh 2-190) — Large Emission Nebula — Known as the Heart Nebula, this large emission nebula resembles a heart and is an active region of star formation.

Object 2: IC 1805 / Melotte 15/ Collinder 26 — Open Star Cluster — Located near the lower-right portion of the Heart Nebula in this image, the Fish Head Nebula is one of the complex’s brightest regions and was the first portion to be discovered. The central dense region is referred to as Melotte 15 or Collinder 26. Young by astronomical standards at 1.5 million years old. The stars in this open cluster are the sculptors of the Heart Nebula as their radiation and powerful stellar winds ionize the gas and clear out the vast bubble in the center.

Object 3: NGC 896 / IC 1795 — Bright Emission Nebula –— Located near the lower-right portion of the Heart Nebula in this image, the Fish Head Nebula is one of the complex’s brightest regions and was the first portion to be discovered. The nebula is an active stellar nursery. It contains dense pockets of interstellar gas and thick dust lanes that are being compressed and ionized by massive newborn stars.

Additional details: The field contains numerous Lynds’ Dark Nebulae (LDN) and multiple bright nebulae from Lynds’ Bright Nebulae (LBN).

Image 3: Annotated image The Heart Nebula (Sh 2-190)

 

Image 3: An annotated image of the Heart Nebula (Sh 2-190).

Imaging Details

·       Capture dates:

o   9/7/2026

o   9/26/2026

·       Location: Eden, NY

·       Target: The Heart Nebula (Sh 2-190)

·       Total integration: 7 hours and 21 minutes total

·       Exposure breakdown:

• 9/7/2026: 52 subs at 180 seconds each
• 9/11/2026: 57 subs at 300 seconds each
• All Exposures: Gain = 100, Offset = 50, and Sensor Temperature = -10 °C

·       Filters: Optolong L-eXtreme (9/7/2026) and L-Synergy (9/11/2026)

·       Moon and sky conditions:

• 9/7/2026: Moon - 17% illuminated, waning crescent, transparency = average, and seeing = average.
• 9/11/2026: Moon: New Moon, transparency = above average, and seeing = average.

Equipment Used

• Telescope: Askar FRA400
• Camera: ZWO ASI2600MC Pro
• Mount: Sky-Watcher EQ6-R Pro
• Filters: Optolong L-eXtreme (9/7/2026) & Optolong  L-Synergy (9/11/2026)
• Guiding: ZWO 30 mm Mini Guide Scope / ZWO ASI290MM
• Control and acquisition software: N.I.N.A & PHD2
• Other accessories: PrimaLuceLab Sesto Senso 3 & SvBony 241 Pro

Processing Details

• Calibration frames: 50 Darks, 50 Flats, & 50 Dark Flats
• Calibration and integration: All pre-processing was performed in PixInsight. Two master light frames were created, one for the L-eXtreme data and the other for the L-Synergy data.
• Star Alignment: The L-Synergy master light frame was registered to the L-eXtreme master light frame using the Star Alignment process.
• Crop: Registration artifacts were cropped from the registered L-Synergy image and the exact same crop was applied to the L-eXtreme image using the Dynamic Crop process.
• Create S II, Hα, and OIII images: The DBExtract script was used to separate the L-eXtreme and L-Synergy data into separate grayscale narrowband images.
• Create SHO image: The grayscale S II (red channel), Hα (green channel), & O III (blue channel) were combined into an SHO image using the ChannelCombination process.
• Background Extraction: The GraXpert process was used to remove any gradients.
• Background Neutralization: The background was neutralized with the BackgroundNeutralization Process.
• Color Calibration: The Color Calibration process was used to help color balance the image.
• Deconvolution: Deconvolution and sharpening were applied with BlurXTerminator.
• Stretching: The image was made non-linear with the Multiscale Adaptive Stretch process.
• Star Removal: the stars were removed, producing separate stars-only and starless images, with the StarXTerminator process.
• Starless Processing:
• Noise reduction: Noise was reduced/removed with the NoiseXTerminator process.
• Adjust Histogram: The histogram was optimized with the Histogram Transformation process.
• Second Application of Noise Reduction: A second application of the NoiseXTerminator process was used to clean up remaining fine noise in the image.
• Normalize the SHO Image: The Narrowband Normalization Process was used to normalize the SHO image.
• Contrast & Saturation: Contrast and saturation were enhanced with the Curves Transformation process.
• Sharpen: The BlurXTerminator process was used to sharpen the image (stellar sharpening and stellar halo reduction were set to zero and a manually entered PSF was used).
• Dark Structure Enhance: Regions of dark nebulosity were enhanced with the Dark Structure Enhance script.
• Star processing: 
• Increased star saturation with the Curves Transformation process.
• Removed green noise with the SCNR process.
• Removed Magenta color from stars with the Correct Magenta Stars Script.
• Combine Starless and Star Images: The PixelMath process was used to screen the stars back into the starless image.

Conclusion

Processing this target was more challenging than I anticipated. Combining data captured through two different dual-narrowband filters with a one-shot color camera added complexity to the workflow, but it also made the result especially rewarding. I hope you enjoyed this image of a giant stellar nursery as our family prepares nurseries of its own for the arrival of our first grandchild.