vendredi 28 avril 2017

Cumulus and WMR200 Oregon Scientific weather station

With the new PC installed, I am now running the weather station all the time. It is an Oregon Scientific WMR200 rather well equipped weather station but I find it highly unstable. I am running it with CUMULUS software which is basic but does the job.
Too many times hardware interface somehow disconnects and the software hangs up. I have been able to work around this by using a script which kill cumulus application every hour and reboot it; this is the script or batch (cumulstart.bat) which I include in the start menu/directory so it launches when Windows 10 boots up:
cd \Cumulus
Taskkill /IM cumulus.exe /F
timeout /T 10
START C:\Cumulus\cumulus.exe
echo Before timeout
time /T
timeout /T 500
echo After timeout
goto loop

Otherwise I am doing a web transfer every 15min of the weather data which is available as graphs on:

I changed a little the code for the main page to insert "inside" temperature & humidity (inside the control room where the weather station is located):

    <td colspan="4" class="tableseparator_temp">Temperature and Humidity </td>
  <tr class="td_temperature_data">
    <th>Indoor Temperature</th>
    <td>2,9 &deg;C</td>
    <th>Indoor Relative Humidity</th>
    <td>54 %</td>
  <tr class="td_temperature_data">
    <td>External Temp</td>
    <td>Dew&nbsp;Point </td>

Here are couple of screens available on-line:

Snowing this april 28th

We got very late snow this year (but weather has been very cooperative so far). This morning around 5h30 snow was covering the garden, the dome and the chicken house...

dimanche 23 avril 2017


Some work beeing done at the observatory:

-new PC (with no mechanical hard drive) installed; much much better and I can leave it ON for long period of time now...

-weather station reinstalled and ok. I had to change the external sensors (Oregon WMR200 model, but spares won't be supported long - a shame!). Weather is now updated every 15min live on:

-LAN at ther observatory is now wired to the house but still use CPL between the box and the LAN line. Testing show a 50% downside in performance but I'm running around 4Mb/s DOWN and 1Mb/sec UP for the ethernet which is more than ok for my need. I should be able to run Astrometry.Net with better performance now...

-The new PC has four seriel ports so I got rid of the Serial/USB converter, much better for reliability as those things are not very reliable.

-outdoor varnish of the newly replaced door and complete southern side of the wooden house

-the Losmandy Titan mount requires a strong refurbishment, this is the next step (CR2032 battery replaced today).

-the garden has never been so cleaned up as I have some time to do it this year...

-two chicken now lives nearby... we got fresh eggs every day now! :-)

mercredi 16 novembre 2016

RCE 2016: Rencontres du Ciel et de l'Espace

Every two years, the french astronomical association (AFA: Association Française d'Astronomie), who is also publishing the major french astronomical magazine "Ciel & Espace", organize a big astronomy fair in Paris: RCE. It takes place at La Villette, a science center in Paris.

RCE is THE major meeting place for amateur astronomers from all the country (and more). There are more than an hundred conferences. Some talks are from key professional astronomers, several are from amateurs presenting their work. This year, I presented an introduction to spectroscopy with some historical background as well as key laxs such as Kirchhoff"s laws and Doppler-Fizeau effect.

Link to the talk slides (french):

At the end, I had the opportunity to see the conference of Hubert Reeves on atoms and their creation (and their abundances in the universe with iron Fe peak and Li-Be-B gap)... It reminded me of a talk he gave 30 years ago at my engineering school (with more equations at that time!), and the ratio He/H just after the big bang... Anyway, it was very nice to see him again! Here are couple of pictures from Stéphane Neveu (my smartphone battery was dead by then!):

Hubert Reeves talk

This show, which attracted around 7500 people, is also a great opportunity to see some new products. This year we had a lot and I can't cover them all. I noticed a new Sharck-Hartmann from Alcor Prism company and an autonomous/automatic visual assisted scope designed by the french startup company Vuonis. This last one has a very nice design and seems a great "toy" for those who just want to see some nice objects, show them to their family/friends & share the images through social networks. A new astronomy in my opinion - anxious to see it in real conditions under clear skies! Here is a picture from Pierre Barroy:

A special note on a low consumption, simple to use but powerful & evolutive AstroPIBox designed by Sébastien Vauclaire & Philippe Deverchère:

 Philippe showing the AstroPiBox to Christian Buil & Valérie Desnoux

Sébastien Vauclair, David Nagler (Televue) & myself
talking about AstroPiBox and other things [Trump! :-)]

 Sébastien was surprised and happy to receive... an asteroid named after him!
I know the feeling... :-)

But RCE is a major place to meet all the friends in the astronomy world! So I was of course in several meal/discussion/groups through the week-end... A very happy moment!!!

a new astronomy tool? no... just France-Sweden soccer match
watched by Christian Buil & ALain Klotz! :-)

One of the (many) dinner group...

Looking forward (already!) for the 2018 edition!!!

mercredi 12 octobre 2016

V711 Tau - a RS CVn star

V711 Tauri is a RS CVn star. It is a binary system with a late evolved chromospherically active star and a main-sequence or sub-giant companion. With a magnitude V=5.64, it is fairly bright and within reach of 0.28m telescope with the echelle instrument. The binary period is 2.8 days.

A key article on this system and why to observe it is there:

telescope inside the dome with optical fibers

On the night of october 9th, I woke up around 1am to check the sky and it cleared up from cloudy evening. I started acquisition of 10 min exposures, signal seemed ok.

 first spectrum of the serie, quickly reduced in ISIS

The signal went up at the beginning as the star was rsing high in the sky but after few hours I noticed the signal was getting poor - a quick check outisde confirmed that clouds were coming back. Oh well, I got 20 spectra covering around 4 hours of time.

observatory control computer screen shot at the end of the acquisitions

I reduced the 20 spectra together to obtain a high signal-to-noise spectrum but I also looked at the individual spectra over time around Halpha, no significant change nor shift seems to appear (maybe a small shift, to be confirmed).

merged spectrum (over the visual domain)

Halpha (order 34) 

spectrogram over 4 hours (Y axis is time, X axis is wavelength); bright line is H alpha

Olivier Garde observed it on october 3rd and I was able to observe it again night of october 11th.

PRISM control screen at the end of the observing run on V711 Tau on october 11th
with Gemini hand controler & telescope camera also visible

Here is a comparison of those three observations, there are some radial velocities involved due to the binarity of this system (Doppler effect):

and the code in MAtLab using my scripts to obtain this graph (modified for the Y legend & title full text):
otz_plot -600 800 0 1 '' -f '_v711tau_20161009_987_34.fits' -f '_v711tau_20161011_950_34.fits' -y p 1 2451142.943 2.83774 -w Ha -s 6549 6550 -x RVH -t s 'V711 Tauri (RS CVn star) - Halpha - Olivier Garde & Olivier Thizy' -l Doi -p png

Here is the spectrogram obtained in ISIS with the one from october 9th (on top) as a comparison:

On can see that Halpha emission (but not only) is actually shifting toward the blue during the approximatly 5 hours total exposure. A graph showing the first and last exposure show a shift of about 40km/s in about 5 hours:

This is promising for the future and more observations are required!...

dimanche 9 octobre 2016

Jour de la Nuit - Le Versoud with GAG

October 8th, 2016 was a national day to switch back the stars. Around 700 event were organized in France. One occured in Grenoble and one in a small city close by - Le Versoud. It was organized by the GAG - Groupement Astronomique du Grésivaudan:

I went to help them and after a talk done by the president of the association, wer were lucky enough to see the Moon between clouds. Around 30 people were there, with lof ot small children.

mercredi 5 octobre 2016

441 days later...


I have my observatory up and running for 441 days now. I looked at my notes and I have observed 60 nights - so around 14% of the nights or an average of more than 4 nights per month.

Total observing hours is around 300h (so 5h in average per night... but winter nights are coming back!). I also have a strong increase after I left Shelyak with 32 nights and 179 hours observing since that time - I am wondering why... :-)

I recorded 230 spectra/targets (around 4 per night) for a total exposure time of 153h (6.4 days!) so an average of 40min total exposure time per target.

My exposure/observing ratio is 51% (in other word, I have around 49% 'overhead' time). This could be just time to start & open the observatory, visual observation with other people (they are included in), time to point a target, maintenance time, etc... There is room for improvement there as 49% is too high. Several issue with guiding and GoTo accuracy due to motor stalled or motor lag is the primary root cause and I'm working to improve it.

I have put my spectra in a personal database, similar to what I use for ARAS spectra I am responsible for. The list of spectra with a thumbnail:

And the last one only with some details for each spectra: