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Hakann
December 18th, 2018, 12:51 AM
I was observing on LaPalma on the Canaries island under the new moon week in December.
That was my 4’th trip to LaPalma in December.

On my first trip I used my Zeiss 2060S bino and I was up on Roque several nights at over 2.000 meter and on the second trip I rented a Mead 16” at 650 meter on the west side just south of Tijarafe.
I also rented a German made Dobson 20” f3.9 that I had up near Roque at 2.000 meter.
I brought my own Ethos EP and Glatter collimation tools.
Third trip I rented the 20” scope again and a 16”.
I had it both outside the house at 650 meter and several nights at Roque.
This trip I rented a 25” f3.2 and used it at 900 meter outside the house. ( located north of Tijarafe also on the west side )
The 16/20/25 was same brand ( Spacewalks )

I had on this trips observing at most nights but I had also both calima as clouds, colder and warmer nights.
Darkness has been pretty dark and last year I had SQM 21.92 at 2.000 meter and this year at 900 meter I had 21.83, but say average is well over 21.6.
It’s always very hazy out to west on Atlantic.

I had amazing nights and this trips has been very education for me ( as I’m rather ’new’ in visual deep-sky astronomy )

I heard weather has no real ’best’ season at LaPalma, that is located west of Morocco in Africa.
But if calima come from Shara it’s no astronomy until it clears out, and it comes often when warmer weather.
Last year and so this year seeing had been a real issue.
I guess best is if winds from north come in.
As the island is very small 55 by 25 km and a crater top at 2.450 meter it is drawing clouds in.
East side has very often clouds when west is ok.

I has been inside both 10.4 meter Canaries and 3.5 meter Galileo and there are several other telescopes there and it’s told one of the best place on Earth.
This year at Canaries they told me on 300 clear nights - but what about seeing.
Ok I heard of arc seeing ’numbers’, but it don’t tell me much.
I’m little worry on the seeing issue there.
-I has plans for my astronomy later on.

This 25” scope had a FL at 2.337 mm whit the paracorr so Ethos 21 mm had around 110X.
I used most 21 mm and the Nikon HW 17/14 mm, but to go higher mag was impossible.
Ethos 6 or 4.7 mm was not to think about.

I guess I’ll just got unlucky on this trips, but this issue whit seeing has brought up my attention down there.
Maybe spring is better, but as I heard spring 2018 was terrible ( most rain )

I had my cheer around the world on bad seeing, but guess my unlock, but I been at great place to as ex in Frankfurt ? ( IVT treffen 2017 )
But LaPalma is important for me vs my plans to clear that out.

Ideas ?

Howard B
December 18th, 2018, 02:28 AM
Bad seeing happens everywhere Hank, but I'm surprised you've had such bad luck at LaPalma. For most places bad to mediocre seeing is much more common than steady seeing, and perfectly steady seeing is as rare as a perfect mirror! Perhaps LaPalma has steadier seeing on a different side of the island or at different altitudes - certainly the summit should have the best conditions of all.

Hakann
December 18th, 2018, 12:58 PM
West side of the island is the best, and not up at north as it is way more wet.
East is often in clouds.
It’s a dark place but I get the feeling this rapid high island might can has seeing issues of huge turbulence.
What that mean for the big telescopes at Roque, I don’t know.
Most of the reporting observations ( I read ) is done whit way smaller telescope than I has use.
After my 4'th trip I know Roque ain’t the cure from 650 meters, if seeing is bad.

Uwe Glahn
December 19th, 2018, 09:05 PM
Hakann,

I know La Palma good because of several observing trips. I also know the location "Athos", their 20-inch and several other places around the island always with large apertures. I also knew some comments of professional astronomers who also work as amateur astronomers on the island.

You speak about the bad seeing conditions. La Palma is famous for its superb conditions on their large telescopes at the mountain top of the Roque de los Muchachos.

To predict the seeing conditions is pretty difficult. It depends on the altitude, the wind speed, the wind direction and the location on the island. To say it in less words:
1) wind speed >10m/s is always a problem (also on the mountain top - look at the seeing monitors of the observatories)
2) strong wind speed from E to SE + location at the W to NW of the island (Tijarafe-Las Tricias) is bad because of lee effects and turbulences from the top
3) the higher, the better
4) Calima brings bad transparency but typically good seeing
5) N places could be a solution when you get a laminar wind from E-NE
6) best season for good seeing is summer-autumn because of less wind speed from E

To work large aperture in La Palma can be disappointing. You have to be mobile and have to check if it is possible to got to the top with best chance to get good seeing. W side around Puntagorda (Athos) is very comfortable and dark. To be mobile is also important because of the different location of the cloud boundary in high and in direction.

Oliver Stein is an (THE) expert for La Palma. If you have further questions you can try to contact him.

uwe

Hakann
December 19th, 2018, 10:43 PM
uwe,

I used Athos 20” at the water tank at 2.000 meter ( east from Puntagorda ) both 2016 and 2017 in December but seeing was bad and 2017 I know all telescopes was cloosed at new moon of heavy turbulance.
This year I only stayed at Athos as I rented the 25”.
I wanted to bring it up at Roque but it was very instabile all nights plus scope could not be moved out.
Idea was get the 20” up.
But I decided to stay at 900 meters whit the 25”.
Owner did ask me on the optics/scope quality but I could not say vs seeing. I told him ok and pretty much is seeing, as darkness is ok vs I had SQM 21.6 or more.

The reason I did not took the 20” up at water tank was I heard they has stopped cars to go to ’flat side’ ( my rental car had a automatic handbrake so...
-I’m not found to stay on road at Roque under the telescopes.
Narrow road, no place to be, cars do come, lights from hotel etc.
It’s not ok for a 20” Dobson my way see it.

My plan now is to has my 18” down there next December.
If so, I will has it over Canaries telescope and rent a car so I can sleap in it.
( then rent a house in Puntagora or closest after LP-4 )

But maybe December is not the best time.

How can I reach Oliver Stein ?

Uwe Glahn
December 22nd, 2018, 09:25 AM
The water tank place could be terrible for the seeing when you have wind speed over the mountain top - you are directly within the turbulence.

And yes, the possibility of setting up the telescope at the top is absolutely unacceptable. The professionals don't want amateurs near the large telescopes and at the top. There is a new visitor centre near the top at 2000m with flat parking area but new LED lights! We are in Europe and I don't like the handling with amateurs, nothing compared to the US stations.

December is for real not the best time. Instable weather with high Passat clouds, cold weather at the top but no Callima.

Oliver's side is http://www.estelar.de You can contact him from there.

Hakann
December 24th, 2018, 12:34 AM
Ok, if they can has lights at the hotel at Roque, I’m not surprise at all to hear they fill the new visitor centre whit LED’s !

Parking will be close at 5 anyway ( as I was told )
When I was there now a security car was there whit parking lights on.
-Very strange.

I heard several observed over the telescope area.
I guess one will need to be very careful whit even dim reds, to not show one is there.
But maybe best to ask first.
Or maybe close to Sweden solar telescope ?
One might can stay in the moon landscape in the dust under centre, but it will be 500 meters lower ( maybe not a issue )
Besides concrete or asphalt is not the best for a bigger plano mirror just 4” over ground.

Hakann
December 25th, 2018, 02:54 PM
I wonder how winds come in to LaPalma normally ?
As I got it, if ex winds come from east to ex Tijarafe ( city is on the west side of iland located around 650 meter on ridge that might be 1.500 meter high ) so Tijarafe will be in lee and that’s not that good for turbulence if one observe from there.
Roque is located on north ridge.

Could not find contac't info to Oliver on his web. ( I has not Twitter etc )

wvreeven
December 26th, 2018, 03:47 PM
A colleague of mine moved to La Palma to become a telescope operator and I will visit him in the weekend of February 2, 2019. Could you please tell me where you rented the telescopes so I can have a look at them and see if I can rent one as well? Many thanks in advance!


Cheers, Wouter

Hakann
December 26th, 2018, 05:51 PM
http://athos.org/
https://www.facebook.com/athos.centro.astronomico/

Come in whit reports later on vs sky quality.

On the security car, it might been vandalism up there (?)
https://www.flickr.com/photos/106029581@N02/46429692801/in/photostream/

wvreeven
December 26th, 2018, 06:19 PM
Many thanks!