Hola and welcome back to our “ExpeditionLaSagra” blog!
It is one year ago from the first “expedition” to La Sagra, and we hope that this will be a full success like the first one with much new discoveries!
The current status is 446 designated, 18 numbered, and one named object – (164589) La Sagra (discovered on 11th August 2007).
The past few months at OLS some things changed. So, for example, we have an new man in our team! This is Francisco Violat, and he is all the time working and living at OLS. We are sure, this will increase the productivity of OLS. One more change is that the Hotel “Collados de La Sagra” has an new owner. But most important that the workers art still the same, so the desert “Volcano de La Sagra” hasn’t changed
One more difference in this the actual “expedition” is that I am here alone with Francisco, without my brother Aleksandar because he joined to an 10 week long summer student project at STScI in Baltimore.
Also our instrumentation is growing! In the next few days, here at OLS should arrive Bill Yeung’s two 0.45m, f/2 Centurions, so we will totally have 3 of them! We will soon be the place with the highest density of AstroWorks Centurions on Earth. 3 out of 30 (or 31) produced so 10%
Now it seems that we could again have perfect weather for more weeks in one part, so I can not promise to post news every day, but I will do my best and let you know all important news!

Best regards,

Stefan 

The night seems to become clear again, after the rain and snow in the last couple of days.

clouds at OLS and OAM tonight and therefore time for blogging…

I was at OLS from Dec. 26 to 30, together with Salvador and Jaime. We met there with Nico, who is now actually on vacation while Alekandar and Stefan do the observations at OLS. Nico came just briefly for one day to the mountain to fix a couple of things that were in need for maintenance. Among them was the new WiMAX link that connects OLS to the outside world and which is important for every day operations, especially now during this dark run where we want to stay in touch with Stefan and Aleksandar on the mountain.

Because OLS is not actually located on top of La Sagra mountain, but rather a few hundred meters lower and north of it, on a neighbouring hillside, there is no direct visibility between OLS and any village. Getting a fast Internet connection was therefore a tough task, but finally it was possible to connect to the WiMAX network of Iberbanda. This was achieved by installing a 6-m high relais tower south-east from OLS on a distant peak. From that peak there is visibility to the peak where Iberbanda has its access point installed, even further to the east.

Last night and today we have seen for the first time bad weather at La Sagra - wind, rain and snow. The weather is much different than in July, when we were here for the first time. But the good thing is that the nights are 11-12 hours long, which enables more discoveries per night (if the weather is good) and very low temperatures which are good for the CCDs

There is also more time to enjoy the nice Winter sky. In the night of New Year’s Eve I have made some images with the Canon EOS 300D. One of them is shown here. It contains: M45 (Pleiades), Comet 17P/Holmes, NGC 884 and NGC 869 (Double cluster), open clusters M36 and M37, and if you look carefully you will also find M33 with the Comet 8P/Tuttle, and a little above them is M31 (Andromeda galaxy).

Picture: Sky over OLS, with two naked-eye comets. The telescope tube seen in the picture is from the 30-cm f/2.8 reflector.

Hi to all,

this is my first opportunity to write something on the blog since we arrived to La Sagra because we had clear weather and were imaging and reducing the images all the time, and now it is raining

From left to right: Stefan, Salvador Sanchez (the director of OAM) and me in front of Collados de La Sagra hotel.

It was really nice to enjoy the celebration of the New Year’s Eve (on Spanish: nochevieja, or fin de año) on Spanish style. Everything began with a magnificent dinner in the restaurant of Collados de La Sagra (http://www.colladosdelasagra.com/), traditionally including shrimp and lamb. The actual countdown and the New Year’s party was organized in the pub of Collados de La Sagra. The way how to greet New Year was completely new for me, the countdown was followed on a TV from the clock on the top of the comunidad de Madrid building in Puerta del Sol square in Madrid and on each chime of the clock we had to eat one of twelve grapes… this tradition has its origins in 1909, when grape growers in Alicante thought of it as a way to cut down on the large production surplus they had had that year. Nowadays, the tradition is followed by almost every Spaniard, and the twelve grapes have become synonymous with the New Year.

After the clock has finished striking midnight, people were greeting each other and toasted with champagne. Then the party begun and ended at  6 a.m., but we went at 23:15 UT (00:15 local time) back to the observatory because we left the telescopes working and had to start new plans.

Since we arrived to La Sagra, we discovered about a dozen new objects from here, while Reiner found a few more (including 2008 AA and 2008 AB) from Observatorio Astronomico de Mallorca while he was doing confirmations and follow-up with two OAM remote telescopes.

Best regards,
Aleksandar

Hi,

After a successful expedition in July, this blog will also be the expedition diary of the two week expedition from 27th December 2007 to 12th January 2008. The goals of this expedition are almost the same as in July – to discover as many minor planets as possible and to write software for automated follow-up. All old posts of the expedition in July can be found below.

Best regards,
Aleksandar

This one-month experiment, that we have named “Expedition La Sagra”, is almost over. Three more nights and the airplane from Granada will depart again with, I think, two happy students on board. For us at OLS this experiment was something new, but it turned out as a huge success. I am therefore sure that it was only the first one with many more to come in the near future.

Aleksandar and Stefan made good use of their stay at OLS by improving their skills in observational techniques and data reduction methods. After a short time of orientation, they worked completely independent – planning the observations, controlling all telescopes and reducing the images the next day. We hope that this knowledge will help them when they enter University life at Zurich, where they begin to study Astrophysics this fall.

For OLS it was a benefit as well. We saw in this long dark run how well certain telescope/CCD combinations work for asteroid and comet surveying and we will use this knowledge to improve the systems further. It will also influence our decisions once new hardware has to be selected for purchase, in order to extend our capabilities in Solar System work.

Up to now this July campaign has a total of 60 credited asteroid discoveries. The most interesting finding was our discovery of the Mars Trojan 2007 NS2. It is only the fourths known Mars Trojan so far and several newspapers did report about the discovery. However all of them missed the real story behind the story, i.e. the fact who discovered it.

I think it is not uninteresting to point out that this discovery was achieved practically by two 19 year old high school graduates within an educational project. And the fact that this object awaited its discovery for decades, being well observable each year, but all professional asteroid surveys failed to discover it. For me these discovery circumstances are the really big news, not just the pure fact that it was found…

Beside the Mars Trojan, a few other interesting discoveries could be achieved, even if not nearly as important. The objects designated 2007 NL2 and 2007 OU6 turned out to be new Jupiter Trojans. 2007 OU6 however needs more tracking data because our orbital calculations show that other orbital types can’t be excluded yet. To be more precise, we get a cometary orbit with very large semimajor axis and eccentricity for it, that fits the available observations better than a Jupiter Trojan solution. Only new data in the next days will tell however.

Below I’ve added two plots that show the situation in the inner Solar System on July 14 midnight UT. The first plot shows the planets up to Mars and the four known Mars Trojans. One of them, (121514), is in the Lagrangian point (well, rather region) L4, while the other three including our 2007 NS2 are in L5.

The second plot shows the planets up to Jupiter and all its Trojans that are known so far. Two objects are marked with white circles. The one closer to Jupiter is 2007 NL2, which very certainly is a Jupiter Trojan. The other one is 2007 OU6 which is suspected to be a Jupiter Trojan as well, but which could still turn out to be a comet on a very elliptical orbit, being just by coincidence close to Jupiter’s L4 cloud at the moment. We will know more in a couple of days.

Finally I’d like to thank the entities that run OLS for supporting this educational experiment. Salvador Sanchez, director of OAM, for his vital support that made this expedition possible at all. Jose Luis Ortiz and Pablo Santos Sanz of IAA, for their organisational help before and during the expedition as well as for their visits to OLS for introducing Aleksander and Stefan to the hard- and software. Jaime Nomen and Juan Rodriguez of OAM, who helped with data reduction and follow-up observations. And last but not least I wish to thank Senor Arturo and Amancio, the owners of the Ressort Collados de La Sagra, for their hospitality. Without the great cuisine at Collados, the long stays on the mountain would be much less convenient

Beside these OLS entities, I’d like to thank Lutz D. Schmadel of the Astronomisches-RechenInstitut Heidelberg for his effort trying to find additional old precovery observations of 2007 NS2. And for allowing me to schedule my day-job at the ARI so flexible that I can “escape” to Spain and Croatia frequently for such projects

Yours,
Reiner Stoss
OAM Observatories and ARI-Heidelberg

Top picture (from left to right): Stefan and Aleksandar Cikota
Bottom picture (from left to right): Jaime Nomen, Reiner Stoss, Jose Luis Ortiz, Pablo Santos Sanz, Salvador Sanchez, Nicolas Morales (currently at CASLEO – Cerro Burek) and Juan Rodriguez

Vadim Burwitz is working at the Max Planck Institute for Extraterrestrial Physics and is at the same time member of OAM. Therefore he asked us for images of M31 in order to confirm a possible Nova discovery made at Skinakas Observatory, Crete, Greece.

We imaged M31 with Sagra2 and helped him to confirm the new Nova. The position of the object is RA(2000) = 00h 43m 03.29s , Dec(2000) = +41° 14′ 52.94″ with an accuracy of 0.1″ and the first measurement yesterday morning showed a brightness of R=18.5 (on 2007 07 19.09367) and this morning R=16.2. For more information, please see this Astronomer’s Telegram.

Click here to enlarge the image.

Stefan and Aleksandar report that the weather at OLS has been marvellous in the last few days. This means the telescopes are collecting photons all night long and both are buried under images that they need to reduce during the day. So I’ll give a short update.

Those of you who read the Minor Planet Mailing List (MPML) will know already: There is now a confirmed fourth Martian Trojan!

To make a long story short… we noticed that this object might be interesting, right from the start when we reported the two nights to the Minor Planet Center (MPC). Our comment in the discovery report was: “Looks like a deep mars-crosser or maybe Amor type”. MPC’s NEO Rating service reported a score of 36% that the object is a NEO.

Our strategy is to make at least three nights for all new objects, especially if they look interesting regarding their orbital type. So we left the two 30-cm remotely controlled telescopes tracking this object on the following night and our new orbital calculations showed the trojanish solution.

We then reported our follow-up observations, again with a comment (“The follow-up we have so far of this Martian-Trojan candidate”) and then contacted Tim Spahr, MPC’s director. He confirmed the interesting orbital type by locating pre-discovery observations by Spacewatch, which improved the calculations. However the orbit was still a bit uncertain and Tim said that before a second opposition is not available, the Trojan status can’t be proven. Still he decided to publish the discovery in a Minor Planet Electronic Circular (MPEC), to draw the communities’ attention to this object. That was on Monday, Its official designation is now 2007 NS2.

On Wednesday, MPC’s associate director Gareth Williams managed to locate old, previously unidentified, observations of this object by LONEOS and LINEAR from 1998. With them, the orbit got very well determined and later that day Aldo Vitagliano (Universita’ di Napoli “Federico II”) confirmed the trojanish status on MPML, after he did a Monte Carlo simulation with 100 clones integrated over a period of 10.000 years. Only minutes later the object was added to MPC’s official list of known Martian Trojans.

With this discovery, the known population of Martian Trojans was increased by 33%. To be honest, the main goal for this one-month observing run at OLS was to discover new NEOs and comets. But hey, there are thousands of known NEOs so far and almost as many comets. The discovery of the only fourth known MT is therefore much more satisfactory

And who knows, maybe the NEO or comet discovery is just a few images away…

Currently there is a discussion on MPML about these objects. If you are interested, jump to the thread here.

Sorry again for the long lag between new posts, but everyone is very busy with observing and reducing data. Stefan and Aleksandar, meanwhile without “jefe” (=boss) at OLS, and OAM folks (Salvador, Juan, Jaime and me) who help remotely by controlling one telescope (the Killer) at OLS and by doing the necessary “second nights”, again remotely but this time with the telescopes at Observatorio Astronomico de Mallorca.

Meanwhile the Croatian press got wind of this story. See for instance this article at Jutarnji.hr .

Hi to all!

It’s now the eighth night in a row that we have perfect sky. After some technical problems at the beginning of the expedition, now all telescopes are working the whole nights mostly without problems. Stefan is controlling Sagra1 and Sagra2, Jose-Luis Ortiz the four Tetras, Reiner and Jaime Nomen the Killer and I do control the Centurion.

Usually we start to prepare (open the shelters and start cooling the CCDs) the telescopes before dinner at 19h UT. When it gets dark enough, at 21h UT, we start to scan the sky and do it for more than six hours, until 03:20h UT. In this time we are able to take with Centurion between 20 and 24 triplets, this means between 30 and 36 square degrees with the limiting magnitude 20. The Sagras are also going pretty deep, maybe even deeper than Centurion, because Stefan is imaging 9×240sec of the same field. Then he stacks 3 by 3 images and blinks them in Astrometrica.

Anyway, we have over 900 measurements of known objects and discovered over 30 new asteroids with the Centurion and the Sagras. 23 of these asteroids have already received designations:

K07N00Y
K07N00Z
K07N01A
K07N01K
K07N01N
K07N01Q
K07N01R
K07N01S
K07N01T
K07N01U
K07N01V
K07N01W
K07N01X
K07N01Y
K07N01Z
K07N02A
K07N02J
K07N02L
K07N02P
K07N02Q
K07N02S
K07N03B

Most of the new asteroids are several degrees away from the ecliptic. With the Centurion we can’t image at less than 40° altitude because of the wall of the shelter, and the ecliptic is in summer quite low. Only with the Sagra1 we are able to image exactly on the ecliptic. But the Centurion will be moved in the new dome soon and then we will have the whole sky available.

It wouldn’t be possible to discover so much without Reiner’s help, because he is doing follow-up of the new objects with the REMOs at Observatorio Astronomico de Mallorca (MPC620), while we are scanning a new part of the sky on each night. Thanks to Reiner and the OAM team therefore.

It is interesting to note that one of these asteroids is probably a Hungaria, and one a Jupiter Trojan. We also have a couple other interesting objects which need more observations to determine their orbital types. More in the next post…

Stefan has also imaged the comet C/2006VZ13 two times while one of the telescopes was free:
http://www.minorplanets.org/ExpeditionLaSagra/img/C2006VZ13_20070709.jpg
http://www.minorplanets.org/ExpeditionLaSagra/img/C2006VZ13_20070713.jpg 

Ciao,
Aleksandar
P.S.: The “Milky Way over La Sagra” was taken by Jaume Andreu. 30sec exp with Nikon D40X. Jaume and Juan Rodriguez (both OAM) were here over the weekend for a short visit.

Weather has been good at OLS in the past few days and that’s the first reason why this blog was so neglected. A second reason is that Stefan and Aleksandar (with “jefe” Jose-Luis) are fixing several problems. The systems at this new observatory are rather “in construction” so most do not work perfectly yet and things can/must be improved. Centurion (45-cm f/2.8) works well and makes good images. Well focused and tracked, after a problem with the attaching of the external guiding scope was fixed. Unfortunately this telescope is not yet mounted in its new dome, but still in one of the shelters. Therefore it cannot access the ecliptic which is currently low in the South. Search area is therefore north of the ecliptic with 240s exposures and 3 visits per field. Due to the “not so high QE” CCD (STL11000M) the Vlim is only slightly better than V 20.0. Expected to find a few dozen new MBAs and with some luck also something more unusual.

Sagras (the two 36-cm f/2) work partially. They give the guys a lot of headache. Problems with software mostly. And without a perfectly working software these telescopes can’t be used properly because the hardware is “undersized” so the system needs to be closed-loop controlled by software. This is true for the undersized mounts as well as for the Hyperstar configuration. I am always wondering how this f/2 setup can work at all on such a messy OTA like a Celestron SC, but it works, and better than expected. One only needs to monitor the focus frequently. And good tracking can only be achieved with autoguiding. Fortunately the ST10XMEs that are mounted to the Sagras have an internal guider, which does the job most of the time. They are supposed to do the follow-up for the Centurion discovery candidates. With 240s exposures they get pretty deep. Typically they make 10 consecutive exposures on the same field. One is typically less good (tracking…) so the remaining 9 are stacked in sets of 3. They reach to V 20.x with this procedure and can therefore track all discoveries from the Centurion.

Killer is scanning very large areas of the sky. Image acquisition is not so much of a problem. The picture you see here is a bit outdated, because meanwhile Killer is mounted on an LX200 fork mount. Mount and CCD are controlled by OAM’s Remosoft, therefore once fed with a few “plans”, it collects images all night long without the need to intervene. There are some issues however involved here. The CCD doesn’t seem to be orthogonal to the optical axis. The adapter that connects the CCD to the Nikon allows some adjustment but it is almost impossible to get it right. Only a slight turn on one of the screws and the image shows considerable coma. Additionally these telephoto lenses were obviously not made for astronomical imaging. A change in temperature shifts the focus considerably. The dew remover that is attached around the lense makes focus drift even worse. Fortunately the night temperature is more or less constant so once a focus was achieved it remains more or less stable. Not perfect, but good enough for the moment. Clearly this system has a lot of room for improvements, by adding a robofocus and a better adapter to adjust the tilting of the CCD camera.

Killer images get reduced the next morning by Jaime’s software. Typically there are about 50 triplets that need reduced. The software is solving them and then running a findmover procedure.. For each detected mover a “croppy” triplet is made (small area of the original image) and this together with the astrometry and some parameters like the rate of motion and the P.A. get added on a webpage. So whenever the observer gets up in the next morning, well, afternoon, he simply has to load that webpage to see the movers detected last night. Currently we are still optimizing the detection settings, because some real known movers get missed, which makes me feel uncomfortable. Even though I am aware that the detection efficiency is never 100%, not even on the big NEO surveys. Well, yeah, PanSTARRS will go over 100%, I am sure…

To help Aleksandar and Stefan, currently the image acquisition and data reduction for Killer get done remotely by Jaime (from Barcelona) and me (from Germany). This is possible meanwhile after the observatory was connected via a radio link a few days ago. So we are now on broadband, thanks to to this WiFi link that connects OLS via a relay-tower to the next village, which is Puebla de Don Fadrique, maybe 15km away. The relay-tower was necessary because there is no direct line of sight between OLS and the village.

I almost  forgot… a few discoveries were also done meanwhile, with designations assigned by MPC. Nothing unusual so far, from what can be said with two nights on each object. Second night’s data came from OAM on Mallorca, via a remotely controlled 30-cm. Thanks go out to Juan Rodriguez and Salvador Sanchez (both OAM) for that! Having such a dedicated telescope for follow-up enables us to go with the wide-field systems at OLS on new areas each night.

Hi!

The weather here at La Sagra during the last two nights was close to perfect! We observed with one of the “Sagra” telescopes, with the Centurion and with the “Killer”. On thursday night we observed only a few fields with the Sagra and Centurion, and focused on the scanning with Killer. The area we scanned with Killer was about 1425 square degrees with a limiting magnitude of approximately 17, due to enterfering moonlight! On friday night we imaged five fields with the Sagra telescope, six fields with Centurion and 1100 square degrees with Killer. In the beginning we had some problems to reduce the Killer images, but today Jaime Nomen, the author of the OAM reduction software, arrived and now we hope that things will go more smoothly. The reason why the searched area with Killer last night was smaller than on the previous night was that we were on a visiting trip to Calar Alto – the big Spanish-German astronomical observatory, just 85 km south of here and we returned to OLS pretty late. 

It was a very nice trip and I am really impressed by the size of the 3.5-m telescope dome, which is nearly as large as the one of Keck Observatory. When we have more time, we will create a gallery with more pictures from this trip. For now please enjoy these previews.

Finally we wish to thank Jesus Aceituno (staff of Calar Alto) and Fran Aceituno and Jose-Luis Ortiz (both IAA) for the interesting tour and a pleasurable stay at Calar Alto.

Ciao,
Stefan

The sky getting dark after sunset on wednesday night. Venus and Saturn above the new dome where the Centurion will be installed soon.

Foggy during second part of the night. Just a few test regions scanned with Centurion and Killer. Let’s hope for more search fields tonight.

Hi,

After an overall 15 hours long trip we finally arrived to Observatory La Sagra. First we had dinner in Collados de La Sagra and I have to say that the food is excellent! In the first night, after we have toured the observatory and the equipment, Pablo Santos Sanz showed us how to work with the Centurion 18. At first we had some problems with the pointing – the pointing error was too big, but later everything was working without any problems. The sky, here at La Sagra, is incredibly clear and was dark, as I have never seen it before, until the Moon raised. I was wondering how the sky can be soo dark. I’m impressed!

Driving to Orio al Serio (BGY) at night.

It is past 1 a.m. and the students should just depart from Zagreb right now. It is a 600km trip by car through the night before they will reach Orio al Serio airport close to Bergamo/Milano in Italy in the morning. From there they have a flight booked to Granada airport (GRX), where they are supposed to arrive at 2:15 p.m. today. OLS is another 2h ride with the car.

So what is the programme for this July observing run at OLS? The goal is to scan as much as possible of the visible sky and find many new asteroids. With some luck maybe a NEO or a comet too. Usually this time of the year, when the large professional surveys are clouded out by the US southwest monsoon, is a promising season for amateur asteroid and comet hunters.

Unfortunately the ecliptic is low in the sky and the summer Milky Way is right in the opposition region, so we’ll have to test how good our detection capability will be in such crowded fields. If the software is not able to handle it, we’ll need to avoid the galactic equator, or go with short exposures and less sensitive parameters just for the bright stuff in those regions.

The two instruments which are supposed to do the most imaging work are a 45-cm f/2.8 reflector with a 11 Megapixel CCD giving a 1.5 square degree field of view (OLS-Centurion), and a 14-cm f/2.8 refractor with a 16 Megapixel CCD giving a 25 square degree field of view (OLS-Killer). Obviously the pixel scale of the Killer is a bit crude with 4.76 arcseconds but it should be good enough to search for bright objects, especially fast-movers. Killer is supposed to scan large areas of the sky for the bright stuff (mag17), while Centurion will go for much less area but to mag20.

Being pretty far south in continental Europe, OLS has currently about 5.5 hours of astronomical darkness. Frankfurt in Germany, just 12° more northern, has currently no astronomical darkness at all but only astronomical twillight with the Sun never going below -12° altitude. So Thank God we are in Spain! Weather prediction for the coming days looks good (see Weather forecast link in the Blogroll on the left panel).

So much for that. Once Aleksandar and Stefan debark at OLS this evening, there will be more.

Ciao,
Reiner

Hola a todos and welcome to the Expedition La Sagra Blog!