9 May 2016 Mercury Transit

The day started out as partly cloudy with a blustery wind up to about 15mph. At 6:30am, the sun was well up, and 45 minutes it both cleared the trees and was to start a morning-long experience with the little planet Mercury crossing its face. Those 45 minutes came and went, and the clouds stayed until about 10am, when things started to clear out. We even had a few strong rain showers, associated with the looming cumulonimbus clouds that were rolling by. The wind picked up, the skies cleared, and the sun came out to play!

We had two telescopes in operation. The newest, the 16″ SCT in the Kurtz Dome was operating with a newly constructed solar filter: Baader solar film and cereal boxes combined with hot melt glue and duct tape. This makes for an excellent off-aperture 6″ screen for the monster scope. The other was our Heliostat which has an inverted Byers fork mount that moves a primary flat mirror to reflect sunlight onto the secondary and then into a 6″ refractor waiting through a hole in the Chart House wall in the library. We had some excellent views and enjoyed visitors from NH and MA as well as several astronomy classes and some members of the astronomy club.

Mercury Transiting the Sun 9 May 2016

9 May Transit of Mercury seen through the 16″ SCT. A Nikon D7000 was used to snap this image which shows the small round dot of Mercury along with two sunspot groups.

16inch_workjing_end

The working end of the 16″ SCT with the D7000 attached for prime focus work.

heliostat_selfie

The heliostat in use. This is also a unique selfie opportunity.

sol_eshel_2016-02-13

Echelle Spectrograph Up and Running

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.

sol1

sol1

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.

ThAr

ThAr

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:

H Aplha

H Aplha

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 😉

sol_eshel_2016-02-13

sol_eshel_2016-02-13

Resistors

Magnetometer in the Making

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.

Parts and pieces

Parts and pieces! This will be the magnetometer when it is all put together!

The keyboard

This is the primary user interface: a keyboard of 4 buttons. These are the only surface mount items to worry about.

The keyboard

This is the primary user interface: a keyboard of 4 buttons. These are the only surface mount items to worry about.

Resistors

Soldering the resistors onto the board. Next will come the capacitors and other parts.

Resistors

Resistors and capacitors in place.

Voltage tolerance test

Resistors and capacitors in place along with voltage regulators. Here we are ready to apply power for the first time to see if the boards voltages are within tolerances.

New Visual Telescope for the Observatory

The observatory took delivery of a new 16″ f/8 ACF Schmidt-Cassegrain telescope this summer. It has been installed, collimated and tested out on a recent clear night. This telescope joins the list of instruments available for swap in the Kurtz Dome. With a 16″ aperture, it has the largest light gathering power of all the instruments at the observatory and also the highest resolving power. We cannot wait until Saturn and Jupiter are in our skies! Stay tuned for information about open houses and other observing opportunities. http://www.twitter.com/PEA_Obs

16" telescope newly installed

The new 16″ telescope just after installation with Dr. Ward and Dr. Adams.

16" First light

On the evening of the 16″ first light. We were able to enjoy nice views of M-16, M-13, M-57 and more.