Category Archives: Astrophotography

Timelapse: A SAMI night at the AAT

See below the new Media Release published by the AAO. This new timelapse video has been also used for StargazingBBC and StargazingABC on March and April 2017.

This new astronomical time-lapse video features the unique SAMI (Sydney-AAO Multi-object Integral-field unit) instrument at the Anglo-Australian Telescope and the beauty of the dark sky over Siding Spring Observatory.

One of the most powerful instruments at the Anglo-Australian Telescope (Siding Spring Observatory, NSW) is the Sydney-AAO Multi-object Integral-field unit (SAMI). SAMI provides 13 fibred based IFUs called “hexabundles” that can “dissect” astronomical objects using spectroscopy. This instrument is used by the SAMI Galaxy Survey, that aims to “dissect” 3000 galaxies in different environments to help astronomers understand galaxy evolution and the tight relationship between gas and stars in galaxies.

However, unlike what the 2dF robot does, SAMI hexabundles must be plugged and unplugged manually very carefully by an expert user.

This video tells the story of a typical observing night with SAMI at the Anglo-Australian Telescope. In the first part, observers carefully prepare the SAMI instrument unplugging the plate they observed the previous night and plugging a complete new plate to be observed that night. SAMI observers usually need half an hour to complete this task, but in this timelapse video it is done in just a minute. Later they move to the AAT Control Room and start observations just as the sun sets. The twilight moves to a moonless, dark night, when only the stars shine over the Anglo-Australian Telescope, providing an spectacular view of the night sky from the Southern Hemisphere, and clear skies for the SAMI Galaxy Survey team to dissect distant galaxies.

In this timelapse you will see the Milky Way rising and setting, the Southern Cross with the Coalsack, the globular cluster 47 Tucanae near the Small Magellanic Cloud, the Large Magellanic Cloud with its strong star-forming region the Tarantula Nebula (30 Doradus), star clusters like the Pleiades moving behind the AAT, Orion rising and setting, the Carina Nebula rising, the magestic Emu in the Sky, and circumpolar stars (with the International Space Station) turning above the dome of the Anglo-Australian Telescope.

All the sequences have been filmed and processed in high resolution (4K) by astronomer Ángel R. López-Sánchez (Australian Astronomical Observatory / Macquarie University) while observing at the AAT for the SAMI Galaxy Survey, between September 2015 and March 2017. He used a CANON 5D Mark III with different lenses, all at f2.8. The night sequences tipically have 24 frames per second, each frame lasting 30 seconds in real time. Therefore 1 second of the night sequences corresponds to 12 minutes in real time.

To enjoy this video, watch it in full screen and at least in Full-HD (4K resolution recommended), in a dark room. As in real live, the details in the sky appear when we are far from the light pollution.

Credits of the video: Ángel R. López-Sánchez (Australian Astronomical Observatory / Macquarie University)
Featuring: Luca Cortese (ICRAR-UWA), Jesse van de Sande (University of Sydney) and Steve Chapman (Night Assistant at the AAT)
SAMI plugger: Ángel R. López-Sánchez (AAO/MQU)
Music: It’s personal (World in flames, 2011), Celestial Aeon Project.

Image

Eta Carinae and the Keyhole Nebula

Eta Carinae and the Keyhole Nebula

Diffuse gas and dust in the heart of the Carina Nebula. The bright star is Eta Carinae, a massive double star at the end of its live that will soon explode as a supernova. The “Keyhole” is the dark cloud in the centre of the image.

Image obtained as part of the “ABC Stargazing Live” events at Siding Spring Observatory (NSW, Australia), 4 – 6 April 2017.

Data taken on 3rd April 2017 using the CACTI camera in 2dF at the 3.9m Anglo-Australian Telescope. Color image using B (12 x 60s, blue) + [O III] (12 x 60 s, green) + Hα (12 x 60 s, red) filters.

More sizes and high-resolution image in my Flickr.

Credit: Ángel R. López-Sánchez (Australian Astronomical Observatory and Macquarie University), Steve Lee, Robert Patterson & Robert Dean (AAO), Night assistant at the AAT: Wiston Campbell (AAO).

Image

Milky Way rising, LMC, and AAT

Milky Way rising, LMC & AAT

Milky Way, Large Magellanic Cloud, and Anglo-Australian Telescope. Combination of. 6  frames, each of 30 seconds, CANON EOS 5D Mark III, 16mm, f/2.8, ISO 1600. Thursday 2 March 2017. The dome was illuminated in one of the frames by a car leaving the building.

More sizes and high-resolution image in my Flickr.

Credit: Ángel R. López-Sánchez (AAO/MQU).

Image

Crescent Moon and AAT

Crescent Moon and the Anglo-Australian Telescope

The Anglo-Australian Telescope (AAT, Siding Spring Observatory, NSW, Australia) is ready for another night observing with the SAMI instrument. A crescent Moon is seen towards the west through the opening of the dome.

Photo taken using a CANON EOS 5D Mark III, 0.6 seconds integration, 70mm lens at f2.8, 400 ISO, Thursday 2nd March 2017, 8pm AEST.

More sizes, including highest resolution image, in my Flickr.

Credit: Ángel R. López-Sánchez (AAO/MQU).

Supernova remnant NGC 2018 with CACTI

Last Thursday 24th November I conducted an outreach exercise while supporting astronomical observations at the Anglo-Australian Telescope (AAT). Using the Australian Astronomical Observatory (AAO) Twitter account I asked people to chose one of 4 given object located in the Large Magellanic Cloud (LMC) to be observed at the telescope with the new CACTI camera while we were changing gratings of the scientific instrument, the spectrograph AAOmega. I’ve called the experiment “LMC Little Gems using CACTI”.

We got 193 votes, thank you to all of you who voted and also shared the post! It was quite exciting, particularly the last 30 minutes when, thanks to some of the best science communicators in Spain (and friends), we got +50 votes!

Well, here are the results:

  1. Cluster + nebula NGC 1949: 22%
  2. Globular cluster NGC 2121: 13%
  3. Supernova remnant NGC 2018: 34%
  4. Cluster + nebula NGC 1850: 31%

I must say my favorite was NGC 1949, but NGC 2018 was also a nice choice.

And the final color image of the object you chose to observe at the 3.9m Anglo-Australian Telescope is:

NGC 2018 - Supernova remnant in the LMC Data taken on 24 November 2016 as part of the AAO Outreach Exercise “Large Magellanic Cloud Little Gems with CACTI”. CACTI camera in 2dF @ 3.9m Anglo-Australian Telescope. Color image using B (6 x 10s, blue) + [O III] (6 x 60 s, green) + Ha (8 x 60 s, red) filters. Credit: Ángel R. López-Sánchez (Australian Astronomical Observatory / Macquarie University) & Steve Lee, Robert Patterson & Robert Dean (AAO) Night assistant at the AAT: Steve Lee (AAO).

NGC 2018, a supernova remnant in the LMC Data taken on 24 November 2016 as part of the AAO Outreach Exercise “Large Magellanic Cloud Little Gems with CACTI”. CACTI camera in 2dF @ 3.9m Anglo-Australian Telescope. Color image using B (6 x 10s, blue) + [O III] (6 x 60 s, green) + Ha (8 x 60 s, red) filters. A high resolution image can be obtained here. Credit: Ángel R. López-Sánchez (Australian Astronomical Observatory / Macquarie University) & Steve Lee, Robert Patterson & Robert Dean (AAO) Night assistant at the AAT: Steve Lee (AAO).

I’ve doing a bit of searching to get some extra information about this object. Indeed, the Large Magellanic Cloud has a high star-formation activity, meaning that star-cluster, star-forming nebula but also supernova remnants are all around the place. However, SIMBAD defines NGC 2018 as Association of Stars, and few references to this object to be a supernova remnant are found (e.g., here).

But looking at the image I can say that this definitively is a supernova remnant, yes, with an associated star cluster too (very probably, the sisters of the massive star that exploded as supernova). How? Well, do you see the filament structure seen in the green colour, that traces the [O III] emission? That is related to a supernova explosion, these features are usually not found in star-forming regions… unless you have a recent supernova explosion, as it is this case!

Thank you very much to all that participated on this outreach exercise! I really hope I can organize another experiment like this sooner than later!