Time: 20:00-22:00 (local time)
Observing site: Tabonal Negro (2362m), Teide N.P., Tenerife, Spain
Instrument: L80/400mm (3” refractor)
Darkness of the background sky: 1
Weather: Clear sky, calm, +13C
Objects observed: NGC 6242, 6281, 6520, 6544
During the fifth and last night of observing during my trip to Tenerife, I drove to yet another different observing spot. During this night I drove to place called Tabonal Negro which is located very near the base of the Peak of Teide at altitude of 2362 meters. I was trying to find a place that would be as far away as possible from any light pollution source, just to see if there are any differences between different observing spots in the Teide caldera.
In this place there was another scenary/viewpoint for tourists which was paved and inteded place for parking cars. Otherwise also this spot was good for observing, but there was heavy traffic during the night and the car headlights were disturbing much. And besides this, there were some people coming to the parking place or leaving it causing severe local light pollution disturbance. So it was practically impossible to observe in peace and solitude as I would like to do. I also noticed that there was not any noticeable difference in observing conditions between this and the other places I went to. It was just as good as the others. Nevertheless, here are the observtions from my last observing night on Mt.Teide:
NGC 6281 (Hidden treasure 80) is a rather large open cluster in the southern part of Scorpius. It is located just 2,5 degrees east from mu2 Scorpii. Of this object I wrote following notes:
According to Skymap pro 9 this should be a large cluster with diameter of 3 degrees, instead the size of the cluster visually appears to be about 1 degree. The cluster is pretty concentrated. Best visible @ 27x
My next target was yet another open cluster in Scorpius known as NGC 6242 (Hidden treasure 79). This object was located in the vicinity of the previous object, just 1 degree to SSE from mu2 Scorpii. It is a pretty small open cluster. Of this object I wrote following notes:
A small, faint-starred and poor open cluster. Low elevation of the object may have affected the appearance of the object.
The third object of the night was NGC 6544 (Hidden treasure 89), a globular cluster in Sagittarius located just 1 degree from M8 to SE. I wrote following notes of this object:
A small, faint globular cluster, even brightness distribution, not resolved.
And finally as the last but not least object of the night and my whole observing trip I observed NGC 6520 (Hidden treasure 88), which is an open cluster 3 degrees south from M8. Of this object, I wrote following notes:
Small, compact and faint open cluster, mostly visible as a starglow.
So, that was my first observing trip to observing southern deep sky objects not visible from Finland. During the trip, I made in total 27 observations during 5 nights. I noticed, that just in terms of the darkness of the sky, Teide is really good but not extraordinarily good. It is as good as Finland is at it’s best – the best SQM readings on Mt.Teide were about 21.4, which is also the best that I have recorder in Finland. The naked eye limiting magnitude was about 6.6, and I have recorder similar NELM’s also in Finland in very dark places. Of course, Teide still has many very important advantages:
- darkness all year round (in Finland light summers restrict observing)
- almost always totally crystal clear sky (in Finland, cloudiness is prevailing)
- almost always pristine, dark sky (in Finland, the sky is always not so dark, because of light pollution, aurorae, etc)
- always comfortable temperature for observing (in Finland, it can be bitterly cold in winter)
- dry air (in Finland air humidity problem is a nuicance every night, especially in Autumn)
- southern objects well observable (although Magellanic clouds are barely below horizon, southern location is huge advantage in comparison with Finland, where northern location restricts objects available)
- easy to travel to
- safe and western
There was one disadvantage though, at least based on my observations: it seems that there is quite a lot of traffic in the roads through the Teide caldera, the car headlights will kill your dark adaptation and disturb observing often. And it is possible, that you cannot observe in peace and solitude. So I would recommend finding an observing spot enough off the main roads where you can observe in peace and solitude.
I’m very happy and grateful that I was able to do this trip! and mostly satisfied with my observations and my results. I hope that this wont be my last observing trip to Mt.Teide! If I will have another chance to travel there to observe, I would focus my observing energy to the objects of Centaurus, Puppis, Vela and Carina.