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10 full nights under the pristine Fall skies of La Palma

November 26, 2017

With the core of our own galaxy, the milky way, disappearing under the horizon, the Fall sky might seem boring at first glance. Think twice about it: colorful airglow, meteor showers, myriads of colorful nebulae and easy-to-spot deep-sky objects, zodiacal lights, satellites and much more... That's the daily spectacle I bought tickets to for ten days, in one of the darkest places on Earth. Are you ready for a jaw-dropping space show?  

 

 

Four and a half hours a day… That’s how long I have slept each day for ten days. Why would I bother being deprived of vital sleep though? Because my mission and goal was to show the night sky in a different way. The second opus of my sequel ‘Galaxies’ aims at finding new techniques and skills to bring the beauties of the cosmos to the general public, and in this optic, I went to spend a bit more than a week in a privileged place: a dark sky reserve. La Palma is located in the Canary Islands, just a few hundreds kilometers west of northern Africa. Its climate and location enable professional and amateur astronomers to gaze at the stars almost year round in a very little light polluted sky. In fact, the cooperation of more than 19 countries in building a giant observatory site on top of its volcano at 2400m is no surprise, because the skies are drier, purer and darker up there. Having shot on top El Teide in Tenerife- the neighbor island, two years before (See video below), I thought it was the perfect place to go shoot the wonders of the winter night sky. Tenerife also possesses decent skies and opportunities to gaze at the core of the milky way, but when your goal is to observe and capture fainter deep-sky red glows, you need a less polluted and bright atmosphere. That’s why I embarked for an epic and restless astro-adventure on Canary’s darkest island.

 

 

Epic and restless, because the objective was to spend all night shooting. So I have done! Every evening I would drive one and a half hours from sea level to 2400m of altitude along the dangerously winding coastal roads to arrive at the top El Roque de Los Muchachos, the volcano. The air is very thin and chilly up there, not to mention the constant wind gusts, making any kind of portable time-lapse astrophotography challenging. I would start shooting from dusk till dawn in the dry cold air, and rest in my rental car while my cameras are shooting. At the break of dawn, I would drive down to my holiday condo and sleep for about 4-5 hours. I needed to get back up, because no matter how much I planned the trip before hand using google Earth to find good shooting spots, you need to scout during the day, otherwise you won’t get a chance to see anything. If you don’t know what dark is, I advise you to get up there. It is so dark because of the basaltic nature of the island's rocks, that almost none of my sequences are taken below ISO 6400 and 10 seconds of exposure, no matter what the focal length is. You need all the light you can gather!

 

For example, I took this stunning vertical panorama of the milky way setting on the Observatorio del Roque de Los Muchachos along with Saturn (yellow dot), Lagoon nebula (pink dot), Scutum (shield constellation) and the pyramidal slanty beam of white light across the milky way emerging from the western horizon: the zodiacal lights. In order to get such an detailed shot, I needed to climb the rocky mirrador along the crater ridge (the Observatory was closed at night!). Then, I needed a close-up lens to get as much detail, and shoot consecutive images that I would stitch together later (6 in total). On top of that, I used a tracker to compensate for the rotation of the Earth and get pin-point stars! I wouldn't have been able to get that much contrasts and details it it hadn't been for the quality and darkness of these skies! 

 

 

 

La Palma is extremely beautiful and weird at the same time. The island is sort of divided into two parts. The first one to the east is the one I didn't go to much, as the road going up the volcano is very dangerous. It receives warm and humid air rising up from the Sahara above the 100km of sea that separate the island from Africa. This causes the east coast of La Palma, and subsequently the eastern slopes of El Roque, to be almost like Hawaii: hot, lush green and extremely humid. Conversely, as the volcano stands in the middle of the island, it blocks all kind of low cloud bringing humidity to the other side. The Atlantic ocean's influence to the west also brings clouds and thunderstorms, but the low clouds seem to magically disappear encountering higher pressures and temperatures from Western Africa, so the west coast gets very little rain. It causes a major change in the fauna and flora from east to west. In the latter, it is very hot and dry, almost like a mediterranean climate, with lots of pine trees, cacti, grassy rocky slopes (Photo above). 
 

 

Now why would I go spend 10 straight days on a cold and windy volcano if the bright side of the milky way isn't there anymore? Besides, the rest of the island is almost constantly under a blanket of boiling low clouds, so you wouldn't even be able to enjoy swimming or sunbathing... Well, because the 'dark side' of the milky way, what we call the 'winter side' (because it is visible in the winter) holds a great deal of other interesting objects and events, and I wanted to include a maximum of them in my upcoming movies with the gear and time I had with me. 

 

Credits: Stardate.org

 

This is when you have to do a lot of planning. Using my app StarWalk 2, I would only focus on what would be available to see in the November sky in La Palma (See on the milky way map above). From 20:30 LT (astronomical twilight) till 6:00 LT, the 'Fall' part of the milky way would be visible as shown on the picture above (APOD). Now there were many things I wanted to photograph, some for the first time, and some others again to get better shots, learning from my past mistakes. The first thing I wanted as I got up there, was the disappearing core of the milky way. I had to be quick, because within two hours after sunset, the whole Sagittarius area along with Saturn would dive under the horizon, and I only had 5 days to do so, after which the moon would be too bright. I really wanted to get some close-up shots of it, from 50 to 135mm. So I did it. I shot three scenes (50, 85 & 135mm) using my Vixen Polarie and the Pure Night filter, to get maximum contrast and detail in the fine dark Hydrogen gas lanes in front of the bright core. Also, how cool would it be to gaze at the Lagoon and Trifid nebulae (enhanced by the modded camera) set in front of foregrounds like telescopes or a sea of boiling clouds? 

As the core was dipping below the line of sight, I would try and photograph the Scutum region (Shield constellation) using the same techniques, but the light emanating from it is not as bright because dark clouds are blocking a lot of it, and also because the bright central bar of our milky way stops somewhere around there. Thus I had to increase ISO or time of exposure. As I was done with the shield, I would consecutively turn to the Swan area. I have shot this area many times before with focal lengths ranging from 14 to 500mm, but I wanted to take advantage of my knowledge and the good conditions to perfect my frames of this area, and get almost noise free, contrasted and colorful pictures out of it. Well even then, it was not as easy as you might think (and this is true for all my shots). First the wind picked up almost every night, compromising the time of exposure and sharpness, especially the shots taken at longer focal lengths. Then November is the perfect time to observe airglow, an upper-atmosphere layer of glowing gas which atoms had been excited by the sun's radiations during the day. It results in bright and colorful gravity waves, but this can dramatically affect the clarity and contrasts of your shots, and it did mine! The Canary islands are also under the constant influence of winds picking up dust and sand in the Sahara and carrying them in altitude over our heads. This considerably increases the haze and noise in your picture. However the real challenge of an astrolapser is the adapt to the local conditions: if the wind picks up, you need to lower your shutter speed to avoid jitter as much as possible, meaning you will have to compensate in any other way. This game of fine manipulation is what makes your astrolapse look good, or horrendous. There is no in between. The slightest slip-up, and you could see the result of a long energy and time investment go to waste (I did have to delete all of my first night’s captures because of misjudgment…). When that being said, I eventually did succeed in getting a clean shot of the Swan area (North-American nebula, Pelican Nebula, Sadr region...). This region also presents some interesting dark dust lanes that are often difficult to show at wider angles because of the noise and too much clarity. I found out in post-processing that reducing clarity reduced the brightness of stars, a bit the details, but dramatically enhances nebulosity. 

Not far from there in the sky, the Andromeda Galaxy was one subject I have attempted time-lapsing before at 135mm and longer, so I really wanted to get a clean shot at it setting behind a foreground. I needed a far-away background while Andromeda was still kind of high up in the sky to avoid too much noise and diffraction from the atmosphere. Unfortunately the island does not really possess such an interesting and bright foreground, so I decided to shoot a scene were it simply disappears behind pine trees. 

 

In that area of the sky, there were also two subjects of interest for me: the Pleiades and the California nebula. I had already imaged the Pleiades at 135mm in the past, so I know it was possible to get the reflective blue light, but would it be possible to time-lapse the blues of the refection nebula and the red of the faint emission nebula in the same frame while guaranteeing enough details and events (shooting stars, satellites) for it to be visually interesting? Well you're going to have to find out in Galaxies Vol. II, but the image above should give you a good hint! 

Going further in the winter night sky as the winter milky way rises to the east, a huge area of interest is coming up: the Orion region. The Orion constellation (The Hunter) is the symbol of winter nights, and was also going to be the focus of Galaxies Vol. II. However, no one has ever succeeded (at least on the internet) to show what's mostly interesting about this area: the beautiful red-glowing gas clouds. The region is extremely rich in emission and reflection nebulae, a testimony of formerly exploded stars. However this cosmic tragedy gives way to a stunning spectacle of light and colors that one ought to take with while shooting astrophotography. That's why I used my Baader astro-modified 6D camera to shoot these nebulae and reveal their true beauty. The best shots are astonishingly at 135mm, where I was able to fit almost all of Barnard's loop, the Orion nebula, the running-man nebula, the horse head nebula and the flame nebula. What was my surprise when I saw that it was not only possible to get so much detail and nebulosity in single frames, but also with a foreground and geosynchronous satellites 'moving' across the frame, giving it a real depth/perspective! Geosynchronous satellites are usually fixed above one Earth location (higher gravity-independent orbit) and usually do not move against the background sky. Nonetheless when you are tracking the sky as I did, these satellites become 'mobile' and you can see them follow each other across the frame, a show that only a few have shown to this date. Eventually I wanted to shoot the nebulosity in the Vela region (Gum nebula), but it was too low on the horizon to do so (it was hidden behind too much airglow and dust).