An update on the build status of the magnetometer. The board has been tested for correct voltages and other parameters. The three sensors have been wired with filter capacitors and connected for some software testing as well. They have not been placed in any permanent housing, and we are investigating best practices for that. We anticipate installation in the fall term once students are back on campus and we regroup. Some images:
Over the past few weeks, the high resolution spectrograph was down due to our working on installation of a new control PC and the replacement of the imaging fiber. The spectrograph is an Echelle design, utilizing a grating design that overlaps 50+ orders of spectra before then being split out into separate rows on an CCD image. The raw spectra image looks like a series of curved lines, but the software does its magic, sorts out which row is which and then reconnects them all into one long, high resolution spectra.
The wavelength calibration is done using a Thorium Argon lamp at the observatory. This lamp generates many well-known emission lines that the spectrograph software then uses to set wavelength values to the spectra of objects being studied. The ThAr spectrum is below with the spectral orders labeled and the identified emission lines wrapped in green boxes.
Once the software has all this figured out, each row is calibrated for wavelength and intensity and is saved in a tremendous FITS file. Below is one small piece of that FITS file for our Sun, the region around 656.3nm, the Hydrogen-alpha line:
Compressed to fit the screen here is a spectrum of our sun (actually clouds above our observatory, because imaging the sun directly would be the last thing we’d want to do with this device!). The image has been saved from Shelyak Instruments EShel software and calibrated within VSpec software. Wavelengths are in ångströms. The violet side shows that we have to work on radiometric correction for the instrument…. in progress 😉
Space weather has long been an interest of mine, and of many of the students passing through my astronomy courses. The interaction of the Sun, it solar wind and our Earth’s magnetic field are just fascinating. Living in high latitudes, we sometimes are given the pleasure of seeing some aurora. In collaboration with the University of New Hampshire, we have taken on the building of a 3 axis fluxgate magnetometer. The unit is from a kit which you can check out here at the SAM-III Magnetometer page. If you are not quite so keen on soldering small components (only a few are surface mount), then you can also order a pre-built one…. but it costs more.
Here is our progress to date in photos.
Here is a short video showing the basic setup and use of the visual observing dome.
One very helpful tool in our observatory operations has been the Clear Sky Chart. This timely clock shows the conditions of sky clarity, haziness, moisture, wind, and temperature all in one handy plot. Skies are generally clear when both Cloud Cover and Transparency fields are dark blue to black in color for any given time. Time is the x-axis with a red vertical line showing midnight. Darkness is measured by both sunlight and moonlight: perfect for those deep sky astronomers who dislike lunar brightening. More information about this chart and how it was made can be found at the Clear Sky Chart Homepage.