Demetra : a new version is available
By François Cochard and Olivier Garde
During the last spectro party at OHP this summer (August 2019), Many of you used Demetra software with your Alpy 600 spectrograph. You gave us some suggestions on this occasion (you also reported some bugs!). It’s mainly following these remarks that we propose you today this new version 184.108.40.206 which you can download HERE.
But this new version also includes new features. Here are the main ones.
A logo for Demetra !
Demetra clearly needed a “visual identity” to communicate better on this software. So we created this logo. The name Demetra refers to Demeter, the goddess of the harvest in ancient Greece; spectroscopy is “harvesting the light of the stars”, and Demetra helps us a lot! What better than a spike of wheat in the colors of the Rainbow to evoke this mission.
We will regularly use this logo to give more visibility to the Demetra software – do not hesitate to give us your impressions.
When you launch the software, the welcome window now tells you which spectrograph the software is configured for.
For the moment, Demetra only processes the Alpy spectra, but eventually it will be able to process the spectra of the other spectroscopes of the Shelyak range. When you download the Demetra Alpy software, it includes a set of demonstration images, made with this instrument (this logic will then be respected for the other instruments, but we’ll talk about it when the time comes).
Display of references lines for spectral calibration
When calibrating a spectrum, Demetra now tells you which reference lines it used during the calibration process. This allows you to immediately see that the calibration went well.
Check the spectral calibration
Similarly, at the end of the data reduction process, Demetra displays the Balmer lines (hydrogen lines). As these lines are present in most stellar spectra, it is a good way to check at a glance that the calibration is correct.
Adjustements to improve user comfort
In addition to these new features, this new version of Demetra corrects some bugs and improves daily use. For example, when the spectral profile is displayed in real time in the acquisition module, we realized that the value of the pixel under the mousse cursor was that of the graph (profile), and not that of the image itself. even. It is now corrected.
Also, if you want to calculate the visualization thresholds in a image zone, you can frame this zone, and make a “double right click” to immediately see all the details of this zone (you can also use the contextual menu, but as it is a very common operation, we wanted to make it even more accessible).
Demetra will continue to evolve in order to make spectro always easier. You probably know that we are actively working on extending Demetra to the eShel spectroscope (we are currently in the testing and documentation phase), but even for the Alpy, Demetra will continue to evolve. So keep telling us all your suggestions: it’s you who know best how Demetra should move forward!