20140110 - Exoplanet Observing Preparation plus some Comet Observations and Images

I had hoped to have been writing up a successful observing run today, but it was not to be. :( However I did manage to put the time to good use and none of the research I carried out for it is wasted. :)

Once the internet was back on I checked the weather for the coming week. It was not looking good at all. It looked as though there was going to be some clear patches last night, then a couple of days of cloud and rain, then a clear night starting at midnight on Saturday and then four days of either cloud, rain or snow!

I checked against my lists of exoplanets to observe to see what transits and secondary eclipses were due to take place last night and created a potential observing list.

Find The Stars

Now the great majority of exoplanet host stars are known by the name of the survey that discovered them, then a number to indicate the order that they were discovered and finally a letter to indicate the planet. The first planet to be discovered orbiting a star is "b", the second "c" and so on. There are exceptions to the rule and when appropriate I will mention them. :)

So the starting point is to identify the star so that I have something to do a "find" or "locate" when using the planetarium programme I use to control the telescope.

The best way to do this is by using an online astronomical database called SIMBAD . It is a fantastic toolset and one that I will mention quite a lot in the future. Today though I will just cover some of the tools.

One of the query options is by identifier and this is the one I start with. It does not have all in them so I will cover a few other options as well. Let us say that the exoplanet I want to know about is CoRoT-1 b. I key in CoRoT-1 - after all it is the star I am interested in. This brings up the correct page. I then scroll down to the Identifier Section where it lists all the other names it is know by. One of the identifiers listed is GSC 04804-02268. This is ideal for my purpose as GSC (Guide Star Catalogue created for the Hubble Space Telescope) is one of the catalogues supported by the SKY programme I use to control the telscope.

If this does not work then I do a simple Google/Yahoo/Bing search on the exoplanet name and GSC and normally that will pull up a paper or a Wiki that will give me the answer.

The last option is again using SIMBAD, but instead of using the Indentifier Query I use the by Coordinates Query and enter the RA and DEC  and this should bring up the star.

This chore is reducing as I have a file that I keep updating each time I observe a different exoplanet.

Location of Star

I know time range that I need to observe (this is in the original observing list) so the next thing I need to do is check which parts of sky these potential options will traverse, (of course it is the Earth that is revolving on its axis and not the sky). I use the SKY programme to help me see where in the sky they will be at different kinds. I eliminate from the list all those that cross the Meridian (imagine a line starting directly to the South, going up overhead, through the Pole and to directly North). This is because the type of telescope mount here is a German Equatorial Mount  which is not capable of tracking across the Meridian.

Prioritise

I then look at what is left in the list. Unless there is any with a special priority I then decide which are the best ones to observe. I take into account altitude, where the Moon is, the brightness of the star, the range in potential magnitude variation during the transit and few other odds and ends LOL `(the odds and ends are actually a blog in their own right as it includes comparison stars and guidestars)

Finder Charts etc

The final thing I can do before the evening is to download any finder-charts I need. Many of the steps taken only have to be done once, so once a you have observed a specific exoplanet, the next time most of the preparation work has been done.

Back to Last Night

On my list I had four options, two rising in the East and two setting in the West. The weather forecast had mentioned a strong wind from the East, so I had a walk up to the observatory to see how strong it was. It was quite strong so I scrubbed the two in the East off the list. I waited a couple of hours for the first in the West, during that time it was clear to the South West, but guess what the cloud came in. The same thing happened at four in the mornings so I packed up and went to bed :(

Hangout about Exoplanets

Talking about exoplanets LOL. On Wednesday evening I attended a google hangout on exoplanets involving Astronomy and Discovery   magazines and chaired by +David Eicher Editor of Astronomy. It was great. No dumbing down, interesting and suitable for all. I look forward to more of them. You can even
ask questions :) so I did :) . I am quite new to this hangout idea, so not sure how long they are kept on line. Here though is the Link to a recording, but how long it will remain live I do not know.Well worth an hour of your time.

While I was waiting around last night

I processed a number of images I had taken a few days ago of some comets. Below is a selection of a few of them. The one good thing about comets is that in a normal exoplanet observing night there is normally time to slot in before, between and after, a few images of comets.  

290P Jager 2014-01-06 20:33 N Mag 13.7
4" Pentax at F4 ST8 clear
SON@OSC
The small boxes - viewing left to right show the progress of the comet over 30 minutes covering about 20 arc seconds.

C/2012 X1 Linear 2014-01-07 04:58 N Mag 10.7
4" Pentax at F4 ST8 clear
SON@OSC

C/2013 R1 Lovejoy UT 2014-01-07 05:46 N Mag 8.3
4" Pentax at F4 ST8 clear
SON@OSC

20131220 - All change in the Observatory

As I mentioned in the previous Blog it is time for exoplanets again.

What is an exoplanet (or extrasolar planet)? It is a planet that is in an orbit around a star other than our own Sun :)

I received a few days ago, along with the other Searchlight Observatory Network Observatories, the agreed list of targets and time table from Professor +Svetlana Berdyugina at Kiepenheuer-Institut für Sonnenphysik .

Svetlana has been observing exoplanets for a number of years. It was Svetlana and her team that discovered, a number of years ago, that a planet (HD 189733b) in orbit around HD 189733 is blue. This was later confirmed this year by Hubble observations.

There are a number of different ways to discover and monitor exoplanets. The current project involves known exoplanets using a technique called Exoplanet Transits. This only works with systems that are near to edge on to us. The observation process involves measuring the change in brightness of the host star when an explanet passes in front of it. The techniques involved are similar to those used for variable star observing. I will write, in the near future, a number of Blogs covering the various methods of discovering and monitoring exoplanets :).

Ideally I should have changed the telescope configuration and started some test runs a few days ago, but after a few months of overall good observing nights the weather changed. We have had clouds, we have icy rain and lots of interuptions with the power.

Yesterday's driving rain stopped me from opening the observatory so with the alarm set early I went up to the observatory to check it out. Apart from a few small wet spots and the need to reset the power everything was OK. It was still fairly cloudy but with holes so I managed to see some stars for the first time in days. It was not suitable for imaging properly but decided to take some images of Comet Lovejoy before changing the configuration.

After these were taken it was time to start to change the configuration.

For the past couple of months the ST8 CCD Camera along with its filter wheel has been on the 4" F4 Pentax refractor and the ST7 CCD Camera was on the C14 F11 SCT.

I now needed to swap the cameras over and also reduce the focal length of the C14 by putting in a focal reducer and once done rebalance the telescope and check that the cable will not get tangled up, (four power cables and four data cables!).

That is the easy bit done! The sky or should I say the clouds stopped most other things being done until this evening and daybreak - providing that it is clear.  So hopefully I will be able to refocus the two telescopes and take new sets of dark, flat and bias frames.

N.B. For none astronomers I promise to do a Blog posting in the next few days explaining the reasons why I needed to change the configuration and what are the effects.

There are a number of jobs I can do during the day, some of which are already under way, including producing an observing timetable.

It is now starting to get dark. There are thick clouds on the horizon and thin cloud overhead. Providing the cloud overhead does not get much thicker I will be able to finalise the configuration, otherwise it will be the case of getting up at four in the morning to check if the cloud has gone and if it has to do the finalisation then.

As there will not be much to show image wise with exoplanets, I will be showing images of various objects that I have yet to process, or will be able to take when exoplanet observing is not taking place.

Other work in progress

I am in the middle of getting another observatory up and running. I have building a roll off structure for it and late afternoon we got it up to the observing area ready for cladding. Pictures tomorrow.

The other day

I mentioned in the previous Blog that a drop in power stopped the telescope mount from working for an hour or so. What I did not mention was that the computer and cameras did not stop.

The following image was taken at ten o'clock at night with just moonlight. It will give you an idea of the power of the telescope (4" refractor) and a time controlled CCD camera :) The distance to the buildings is about three miles.