Category Archives: Nebulae

Video: Understanding the colours of nebulae

Today I’ve released in my YouTube Channel the very first video of a series that seeks to connect professional astrophysics with amateur astronomy and outreach. This video, is entitled “Understanding the colours of the nebulae“, or why square brackets are important when naming metallic transitions in nebulae.

Do you know how profesional astrophysicists and amateur astronomers get vibrant colour images of nebulae? In this video I provide insights of the Physics behind these images. I emphasise why the ionic transitions of metallic elements (i.e., any element that is not hydrogen or helium) in nebulae must be written with brackets, as they are not recombination lines but collisional excited lines, that is, a kind of forbidden lines that only appear in extreme low-density gases because of the collision of ions with free electrons in the gas.

The video includes my subtitles in both English and Spanish.

An extended article about the video will be added here soon.

I hope you like it! And remember:

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The Trifid Nebula from Sydney

The Trifid Nebula, M 20, from my backyard, 15 km North from Sydney’s city center, on 15th June 2020.

This image compiles 40 x 300s images (3.3 hours total integration time) obtained with my Skywatcher Black Diamond 80, an Orion X0.8 focal reducer (f/6), the ZWO ASI178MC camera and an OPTOLONG L-Pro filter.

I used the ZWO ASIAir to control the camera, the mount (Skywatcher AZ-EQ6) and the guiding system (ASI120MM + Orion 50mm finderscope).

Flats and darks included. Data processed with Siril software. Color / saturation / levels / contrast / smart sharpen with Photoshop.

Full resolution image in my Flickr.

Credit: Ángel R. López-Sánchez (AAO-MQ).

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The Heart of the Carina Nebula in H-alpha

The center of the Carina Nebula, with the bright star Eta Carinae and the Keyhole feature, in H-alpha.

Data taken from the backyard at home, ~15 km from Sydney’s city centre, on Monday 19th and Tuesday 21st April 2020.

Equipment: Skywatcher Black Diamond 80 (F=600mm, f/7.5), Skywatcher AZ-EQ6 (mount), ZWO ASI178MC (main camera), ZWO ASI120MM + Orion 50mm guidescope (guiding), 2″ Baader ultra-narrow (3.5 nm) H-alpha filter, and ASIair controlling everything (using my son’s iPad).

This image combines 35 x 600s light frames, and 30 x 600s dark frames. Aligned and stacked with SiriL, stretching, colour contrast, saturation, levels, and luminosity with Photoshop.

Full resolution image in my Flickr.

Credit: Ángel R. López-Sánchez (AAO-MQ).

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M42 from Sydney

Image of M 42 (The Orion Nebula) from my backyard, 15 km North from Sydney’s city center, on 10th Mar 2020.

Equipment: Skywatcher Black Diamond 80 (F=600mm, f/7.5), Skywatcher AZ-EQ6 (mount), ZWO ASI178MC (main camera), ZWO ASI120MM + Orion 50mm guidescope (guiding), 2″ UHD Optolong filter, and ASIair controlling everythin (using my son’s iPad).

This image combines 60 x 20s light frames, and 21 x 20s dark frames. Aligned and stacked with SiriL, stretching, colour contrast, saturation, levels, and luminosity with Photoshop.

Full resolution image in my Flickr.

Credit: Ángel R. López-Sánchez (AAO-MQ).

My contribution to 2018 #StargazingABC

How can I say it in just few words? It was both very exciting and exhausting, with a little bit of bitter too. But, overall, last week at Siding Spring Observatory was one of the best experiences I have had in a long time working at the telescope, combining science research, amateur astronomy, outreach and science communication during the Stargazing ABC Live shows.

The AAT is ready for #StargazingABC. Hosts Julia Zemiro and Prof Brian Cox are sit in the piano, while Brian still rehearsing. Credit: Ángel R. López-Sánchez.

When I’m writing this, at 6:44pm 30th May 2018, I’m still observing at the Anglo-Australian Telescope. I’m doing it remotely from Sydney. It is my last night in a very long run (18 nights in May) for my own research project, which I will detail here eventually. I’m exhausted and need a good break, body and mind can’t survive this crazy rhythm, sleeping an average of 4-5 hours per day, and without any break during the weekends.

But let me at least quickly mention here my contribution to the 2018 Stargazing Live shows:

1. I provided A LOT OF information about Astronomy and the Anglo-Australian Telescope to the ABC and BBC crews. This is something that I’ve been doing during the last months, and might be considered as part of my role of “AAO Science Communicator Officer”.

2. I provided plenty of astrophotography and video-timelapse material, which was used during the shows. The most important of these is the new timelapse video “Stargazing at Siding Spring Observatory“, that you can enjoy here:

3. I spent some of my scheduled time at the Anglo-Australian Telescope to prepare a nice, new image of a beautiful astronomy object, that was later discussed during the show. It was the planetary nebula NGC 5189, for which I provided extra information in the previous post.

4. But the most important contribution for the show was actually observing with the AAT two transients reported by the citizen scientists who participated in a program to search for type Ia supernova in other galaxies. After confirming that the transient was there, we got spectroscopic information using KOALA+AAOmega, reduced the data, analysed the data, confirmed that both transients were type Ia supernova in distant galaxies, and wrote a science report with the discovery!

This was something I originally didn’t plan to do, but, as I said, it was my own research program that scheduled at the AAT during the StargazingABC, so I decided to do it and it got a reward, as this also allowed us to submit two science reports with the discoveries!

These two nights were really exciting! I really want to thank my friends and colleagues Lluís Galbany and Yago Ascasibar, as well as the AAT Night Assistant Kristin Fiegert (AAO), for their wonderful help in all of this.

The discovery of the transients and the confirmation that they were type Ia supernova in distant galaxies has appeared in many media news these days, including in ABC Science News, and also here: “Citizen scientists find two supernovae and (slightly) revise the age of the cosmos“.

It was also a privilege talking with Prof Brian Cox, who is absolutely great, and even recorded a short video with me for my son. Thank you a lot, Brian!

Prof Brian Cox and me are ready for #StargazingABC.

Where is the “bitter” I mentioned in the first paragraph? Well it is when the credit is not given. And not credit was given to me during the shows. I was still hoping at least having my name in the screen, in an ideal world even participating in person during the shows. But with my name (Ángel) and my strong English accent… well… perhaps in another life… I know what I did and I know how important my contribution was, and as I said I really enjoyed a lot all the time.

I hope I’ll be back if #StargazingABC returns in 2019!

PS: If you are in Australia, you can watch anytime the 3 episodes of 2018 #StargazingABC following this link to the ABC webpages.