Tag Archives: Nebulae

Video: Understanding the colours of nebulae

Posted on July 5, 2020 | Leave a comment

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:

Leave a comment

Posted in Amateur, Astrophotography, Astrophysics, Emission Nebula, History of Astronomy, Nebulae, Observation, Outreach, Profesional, YouTube

Tagged , , , , , , , , ,

Image

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).

Leave a comment

Posted on April 22, 2020 in Amateur, Astrophotography, Emission Nebula, Nebulae, Observation

Tagged , , , , , ,

Image

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).

Leave a comment

Posted on March 21, 2020 in Amateur, Astrophotography, Emission Nebula, Nebulae, Observation, Optical, Star Forming Regions

Tagged , , , ,

Image

Test of M8 from Sydney

Test image of M 8 (The Lagoon Nebula) from my backyard, 15 km North from Sydney’s city center, on 21st Aug 2019.

That was my first attempt to get the new equipment working. I was testing the Skywatcher AZ-EQ6 mount and the ZWO ASI120MM (guiding) and ZWO ASI178MC (main camera) with the ASIair. But I had plenty of problems to get the guiding working as the mount was not properly aligned to the South Celestial Pole (over Sydney, very difficult to see the faint stars using the polar scope of the mount). I had to use the drift method. After that, getting the ASIair properly guiding was hard as I couldn’t find any easy manual and never used PHD for guiding before.

This image combines 25 (of a series of 60) good 180s frames using the ZWO 183MC and my Skywatcher Black Diamond 80 (F=600mm, f/7.5. No darks, flats, biases or light pollution filter was used for this.

Later it was also tricky for me to play with the raw data: I have never used a color camera producing .FITS files before! It took me some time to get a good free(*) software for it and I found Siril. But the “bayer” decomposition didn’t work well with the ZWO cameras and my images had very weird colours.

In March 2020 I learnt a couple of extra things, including changing the bayer matrix from RGGB to GBRG for ZWO cameras and… bingo! So here it is the test image I got that night more than half a year ago! And still testing the equipment!

Ah, yes, stretching, colour contrast, saturation, levels, and luminosity with Photoshop.

Full resolution image in my Flickr.

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

(*) Don’t get me wrong… I’ll get PixInsight eventually, when I get everything working well.

Leave a comment

Posted on March 8, 2020 in Astrophotography

Tagged , , , , , , ,