Last week, NASA released the latest image from the James Webb Space Telescope, a close-up view on the molecular cloud complex Rho Ophiuchi. This is a bright and colorful object located in the constellation Ophiuchus, 400 light years away and very close to the Milky Way core. Here is that image:
Rho Ophiuchi, JWST and me
Rho Ophiuchi is also known as XSS J16271-2423; it is the closest stellar nursery to Earth and includes the bright orange star Antares.
The timing is perfect because, for the past few weeks, I have been working on gathering data on this exact same target with my own amateur telescope.
For the first time in my astrophotography journey, I decided to do a 2×2 panel mosaic of this object to get a very high-resolution image that shows the entire molecular cloud complex. I used 300-second exposures for about 2-3 hours on each panel and then stitched and processed everything. You can see the final image below:
This object is very low in the sky, so it is not easy to photograph. This is because the light from the nebula and stars goes through some atmospheric disturbance. Being so low, I was only able to spend 2 hours per night while it was at its highest position.
My telescope is installed at a remote observatory called Utah Desert Remote Observatories. This allowed me to capture data every clear night and under very dark skies. The dark skies especially matter here because this object is mostly a broadband target, meaning it can be shot without any filters.
- Telescope: Celestron RASA 8
- Camera: ZWO ASI2600MC
- Mount: 10Micron GM1000HPS
- Computer: Eagle 5S
- Filters: None
The sky quality on this shoot was two. (Generally, the sky quality ranges on a scale from one to nine -9, with one (Bortle one) being the least light polluted.
The image above shows the exact equipment used to capture this image.
Rho Ophiuchi shooting challenges
NASA’s photo of Rho Ophiuchi is much clearer and with better resolution, as expected. That said, here are some of the factors that make JWST’s images clearer and show the importance of having this wonderful device.
As I mentioned before, shooting conditions are not ideal: The low position in the sky, creates atmospheric disturbance; The light pollution, even at level two, is not zero. JWST, begging so high, obviously is not impacted by those two factors.
But, also, the post-processing part of the image creation is not trivial:
The data was not easy to process. First, all the images had to be debayered, calibrated, and aligned. Then, the images had to be divided into their respective panels and stacked to create four master files.
The four master files then had to be plate-solved and stitched together into the processing software (PixInsight).
This process created some residual black lines on the edges and a few inside the image. Those had to be fixed as best as possible so that they were no longer visible.
Lastly, the image was processed like any other deep-space image, being careful to bring out as much detail and colors as possible without bringing out noise or unwanted artifacts.
Are you able to spot the section photographed by NASA’s JWST on my amateur image? If not, this will help! This comparison image shows Rho Ophiuchi three times:
- Shot with a DSLR and a wide lens
- Then shot again with my telescope (seen above)
- And, lastly, the photo from JWST
It’s always fun when you spend several nights imagining an object and see that NASA releases a new picture of that same object!
About the Author
We are Antoine and Dalia Grelin. For the last ten years, we’ve been honing our skills as amateur astrophotographers. Our goal is to motivate people to jump into this wonderful hobby of astrophotography and help others to capture their first images of the night sky.
We do this through videos on our Galactic Hunter YouTube channel, hundreds of written tutorials on our astrophotography website, and through books about astrophotography. Half of our images are taken from the desert, far away from all the light pollution of the city, and the other half from our backyard in Las Vegas, NV using specialized filters