Category Archives: Observation

Partial solar eclipse from Sydney

Today, 10th May 2013, the combined movements of the Sun, Earth and Moon gave us a very nice Annular Solar Eclipse. Following a similar path to the Total Solar Eclipse we enjoyed last November, the shadow of the Moon over the Earth moved from North Australia to the Pacific. However, today the Moon was close to its maximum distance to the Earth (planets and satellites move following elliptical orbits) and hence its apparent size on the sky was not big enough to completely cover the disc of the Sun. This is indeed the reason the eclipse was an annular solar eclipse.

In this occasion I couldn’t travel to North Australia to enjoy the annular eclipse (actually, I have seen 2 of these in the past, the most recent one was on 3rd October 2005 from Madrid), and even last night I didn’t expect to do anything special about this today. But this morning, while watching it from my backyard using my solar glasses, I decided just to take some few shots using not the telescope but only the tele lens. This is the result:

Partial Solar Eclipse from Sydney. Data obtained using a CANON EOS 600D, a 250mm Tele Lens and a Solar filter (which I hold by hand). I stacked 12 individual frames obtained at ISO 100, f10, 1/80 s using the Lynkeos software. The final processing was achieved using Photoshop. 10 May 2013 @ 09: 10 AEST ( 00:10 UT ), Sydney, Australia.
Credit: Ángel R. López-Sánchez (Australian Astronomical Observatory / Macquarie University, Agrupación Astronómica de Córdoba / Red Andaluza de Astronomía)

I hope you like it.

Timelapse video: The Sky over the Anglo-Australian Telescope

A dark winter night, with the Milky Way crossing the firmament while its center in located near the zenith, is one of the most astonishing views we can enjoy. This vision is only obtained from the Southern Hemisphere and it is really inspiring. In particular, the Milky Way shines over the Siding Spring Observatory, near Coonabarabran (NSW), where the famous Anglo-Australian Telescope (AAT) is located. With the idea of sharing the beauty of the night sky to everybody, in May 2011 I decided to start taking timelapse photography while I was working as support astronomer at the AAT. This technique consists on taking many images and then adding all to get a movie with a very high resolution. The best shots I obtained by September 2011 were included in the video The Sky over the Anglo-Australian Telescope, which is available both in YouTube and in several MOV/MP4 files (HD, iPad, iPhone) in my personal AAO webpage.


“The Sky over the Anglo-Australian Telescope” was my first public timelapse video, released in November 2011.
Credit: Ángel R. López-Sánchez (AAO/MQ), the credit of the music is Echoes from the past, by Dj Fab.

The video, which lasts for 2.7 minutes, is the results of combining around 3800 different frames obtained using a CANON EOS 600D between June and September 2011. Except for those frames used for the sunset in the first scene, all frames have a 30 seconds exposure time, with a ISO speed of 1600. As the videos were created at 24 fps (frames per second), each second in the movie corresponds to 12 minutes in real time. I used several lens to take the images (standard 50 mm, 50mm x 0.65 focal reducer and a 10 mm wide-angle lens). The focal chosen was 5.6 (for the 50 mm lens) or 4.5 (10 mm wide-angle lens). Processing each sequence of the movie took five to six hours of computer time, and usually I had to repeat this at least once for each sequence, to improve the quality. The soundtrack I chose is an extract of the music Echoes from the past, by the french composer Dj Fab, which gives energy to the timelapse.

The Milky Way is setting at Siding Spring Observatory on 21 Sep 2011.
Click here to get the full resolution frame.
Credit: Á.R. L-S.

As my main job while I’m at the AAT is providing instrumental and scientific support to the astronomers who are observing in this telescope, I always set the camera up at the beginning of the night, let it run, and check on its progress occasionally. Sometimes this was not easy: wind knocked the camera over on a couple of times, often the battery ran out, and even once I had an encounter with some intransigent kangaroos. However, finally I got this material, which does not only show the magnificent Milky Way rising and setting above the dome of the AAT, but also stars circling the South Celestial Pole, the Magellanic Clouds over the AAT, satellites and airplanes crossing the sky, the Moon rising and setting, and the most famous constellations as Orion, Carina and the Southern Cross.

Circumpolar star traces (2.7 hours) over the Anglo-Australian Telescope on 20 Sep 2011.
Click here to get the full resolution frame.
Credit: Á.R. L-S.

I hope you enjoy the result. More timelapse videos to come soon!

Moon, Jupiter, Jewel Box and Comet Lemmon

Besides being an astrophysicist I’m an active amateur astronomer. After 6 years living in Australia, finally in May 2012 I bought my own, small amateur telescope: Skywatcher Black Diamond Refractor Telescope, with an aperture of 80 mm and a focal distance of 600 mm. It provides beautiful images of the sky. However, besides once while stayed at Siding Spring Observatory and the two “great astronomical events” of 2012 (and the final reason I got the telescope), the Transit of Venus in June and the Total Solar Eclipse in November, I have not had too much time to play with this toy.

Last Monday 18th February it was clear in Sydney and I tried to get some shots of the conjunction between the Moon and Jupiter (actually, from South Australia the Moon occulted Jupiter!). This is the vision I got from my telescope:


Conjunction between the Moon and Jupiter observed from Sydney on 18th February 2013. I used my Skywatcher Black Diamond Telescope D = 80 mm, f = 600 mm and my CANON EOS 600D at primary focus, at 200 ISO. It is a composition of two images: one taken at speed 1/60 and another at 1/10. I did what I could to get a nice balance between them. Credit: Angel R. López-Sánchez.

After this, I decided to try to find the bright comet Lemmon 2012 F6, that was located near the Small Magellanic Cloud. It was actually easier I thought and, besides the light pollution, I got it. So on Tuesday 19th, again clear, I prepared the telescope but this time including the motors and performing an alignment of the mount to the South Celestial Pole. This task is not easy when there is too much light in the sky, as the stars used to do it are faint. At the end I got this view of the comet. I was not able to detect the tail with my eyes, however it does appear when combining several frames, as I did for this image.

My vision of the comet Lemmon 2012 F6 from Sydney on Tuesday 19th February 2012, at 21:20 AEST (10:20 UT). I combined 7 frames of 6 seconds exposure each (42 seconds total exposition time), at 1600 ISO using Skywatcher Black Diamond Telescope D = 80 mm, f = 600 mm and my CANON EOS 600D at primary focus. Note the faint tail moving towards the upper-left. Credit: Angel R. López-Sánchez.


An annotated version of this image can be found here:


Annotated version of my vision of the comet Lemmon 2012 F6 from Sydney on Tuesday 19th February 2012, at 21:20 AEST (10:20 UT). I combined 7 frames of 6 seconds exposure each (42 seconds total exposition time), at 1600 ISO using Skywatcher Black Diamond Telescope D = 80 mm, f = 600 mm and my CANON EOS 600D at primary focus. I have included an arrow folowing the faint tail, the orientation, and the position of the star &epsilon Tucanae. Credit: Angel R. López-Sánchez.

To get a good focus I decided to use the famous Jewel Box star cluster, very close to Mimosa (β Crucis).


Image of the “Jewel Box” star cluster (NGC 4755 or Kappa Crucis) in the Southern Cross from Sydney (actually, 4 km from the city center) on Tuesday 19th February 2013, 20:50 AEST (09:50 UT). It combines 6 images with 5 seconds exposure each ( 30 seconds total time) at 400 ISO, using a Skywatcher Black Diamond Telescope D = 80 mm, f = 600 mm and my CANON EOS 600D at primary focus. The bright star at the left is Mimosa, β Crucis, one of the brightest stars of the Southern Cross. Credit: Angel R. López-Sánchez.


Any of these images are very spectacular but considering that they have been taken just 4 km from the center of Sydney, with all the light pollution, plus the extra “fight” with the mozzies, I’m happy to share them with you.

NEA 2012 DA14 observed from the AAT

Yesterday I explained we are resuming the scientific observations at Siding Spring Observatory (NSW, Australia) since the recent bushfires on 13 January 2013. Today we have used this telescope to observe the Near Earth Asteroid (NEA) 2012 DA14, which is getting its closest encounter to our planet today (it will be at only 27000 km from the surface of the Earth). Here you have the details:


The path of the NEA 2012 DA14 from the AAT. Observed during the evening twilight on the 15 February 2013 using the FPI camera of the 2dF instrument at the 3.9m Anglo-Australian Telescope located at Siding Spring Observatory (NSW, Australia). 25 frames, 2 seconds exposure each, 5 seconds between frames. First frame obtained at 09:53:54 UT, last one at 09:56:22.
Support Astronomers: Lee Spitler (MQ/AAO) & Andy Green (AAO).
Night Assistant at the AAT: Steve Chapman (AAO).
Edition of the data and movie: Ángel R. López-Sánchez (AAO/MQ).
Link to the video in my Flick.

The data were obtained by Lee Spitler (MQ/AAO), Andy Green (AAO) and Steve Chapman (AAO) during the evening twilight while waiting the sky was dark enough to start the scheduled scientific observations. We will try to get more data of this object during the morning twilight. More to come soon!

Update at 14:45 AEST, 16th Feb 2013

I’ve checked there are some problems to watch the video using smartphones and tablets such iPhones and iPad. Just try this link and it should work, although you may get a low resolution version of it. I’m creating a new video to be uploaded to YouTube. At the same time, I’ve just finished this image showing a mosaic with 13 of the frames obtained for the video.

Mosaic with the path of the NEA 2012 DA14 from the AAT. Observed during the evening twilight on the 15 February 2013 using the FPI camera of the 2dF instrument at the 3.9m Anglo-Australian Telescope located at Siding Spring Observatory (NSW, Australia). Each frame has an exposition time of 2 seconds.Times are shown in Universal Time (UT), add +11 hours to get the local time in NSW.
Support Astronomers: Lee Spitler (MQ/AAO) & Andy Green (AAO).
Night Assistant at the AAT: Steve Chapman (AAO).
Edition of the data and movie: Ángel R. López-Sánchez (AAO/MQ).


Finally, I confirm we also observed the NEA at the AAT during the morning twilight.

Update at 16:55 AEST, 18th Feb 2013

An updated version of the video, which is now in HD and includes the celestial coordinates, has been included in this excellent article published today in The Conversation by Simon O’Toole (AAO).


The path of the NEA 2012 DA14 from the AAT. Observed during the evening twilight on the 15 February 2013 using the FPI camera of the 2dF instrument at the 3.9m Anglo-Australian Telescope located at Siding Spring Observatory (NSW, Australia). 25 frames, 2 seconds exposure each, 5 seconds between frames. First frame obtained at 09:53:54 UT, last one at 09:56:22.
Support Astronomers: Lee Spitler (MQ/AAO) & Andy Green (AAO).
Night Assistant at the AAT: Steve Chapman (AAO).
Edition of the data and movie: Ángel R. López-Sánchez (AAO/MQ).

Back observing at the Anglo-Australian Telescope

On 13th January 2013 the Siding Spring Observatory and the beautiful Warrumbungle National Park near Coonabarabran (NSW, Australia) were terribly affected by the worst bushfire in NSW in the last decade. Although the astronomical facilities have not experienced any severe damage, the bushfire has destroyed some houses at the Observatory (including the Lodge), burnt tens of houses and destroyed the majority of the trees in the National Park.

However, tonight Thursday 14 February, after a month and a day since the bushfire, astronomers are recommencing observing with the 3.9-m Anglo-Australian Telescope at Siding Spring Observatory. I’m one of these astronomers who are now performing the observations remotely from the Australian Astronomical Observatory (AAO) headquarters in North Ryde, Sydney, supported by technical staff at the telescope. The AAO has made public today a press release informing that astronomers are back to work at the AAT!.

The Spindle Galaxy with the AAT. It is an edge-on lenticular galaxy classified as NGC 3155 or Caldwell 53. The data were obtained on 14 February 2013 using the FPI camera of the 2dF instrument at the 3.9m Anglo-Australian Telescope located at Siding Spring Observatory. 8 x 20 s + 5 x 40 s + 1 x 60 s integration time (460 s), combined with IRAF. Colours derived using U, V and I images obtained at the 2.5m Cerro Tololo International Observatory by Kuchinski et al. (2000).
First astronomical observations after the bushfires on 13 January 2013.
Credit: Ángel R. López-Sánchez (AAO/MQ) & Lee Spitler (MQ/AAO),
Night Assistant at the AAT: Steve Chapman (AAO)
.

Although we are using tonight the Two Degrees Field (2dF) instrument with the AAOmega spectrograph, which allows the acquisition of up to 392 simultaneous spectra of objects anywhere within a two degree field on the sky, we have also used the auxiliary camera that 2dF possesses, the Focal Plane Imager, to take some images of the Spindle galaxy, also known NGC 3115 or Caldwell 53, a lenticular (S0) galaxy located at around 32 million light years from Earth.

However, tonight’s observations are having the AAT looking up to a billion light-years out into space to test our ideas about the still mysterious Dark Energy.