Amateur Astronomy

After arranging a mirror to direct light into my spectroscope and arranging a camera to take macro-photographs of the vernier, I had a much easier time measuring spectral lines. Below is an image that I took today, along with an annotated diagram created with my Matlab script.

The wavelengths that I observed are:

486.1 (hydrogen-beta -- used as a reference)
516.6 (unresolved doublet, Mg and Fe)
517.1 (Mg)
518.0 (Mg)
527.3 (Fe -- not shown on these diagrams)

The annotations in the second image are literature data (from Wikipedia), not observed data. All wavelength values are in nanometers.

Twinkle, twinkle, little star,
How I wonder what you are!
Up above the world so high,
Like a diamond in the sky!

-- Jane Taylor, "The Star", 1806

Today I happened to notice that the sun was shining through the window and directly onto a spectroscope that was sitting on my bench. I purchased this piece of equipment on eBay several years ago and am now in the process of returning it to working condition. The slit is still a jerry-rigged assembly of masking tape and aluminum foil, but I thought I'd take advantage of the favorable position of the sun to see if I could observe any spectral lines. This is something that I've tried before, but have never successfully accomplished.

After aligning the first telescope with the sun, I positioned the 2nd telescope for viewing and the lines could not have been more obvious. To record the event I grabbed my digital camera (just a little Casio -- nothing particularly fancy) and held it to the eyepiece. The following are some of the spectra that I observed:





I am fairly sure that the doublet in the orange portion of the last (bottom) spectrum is due to sodium (the D lines). Unfortunately there was not enough time to measure the wavelengths of these lines due to the position of the sun (it was only minutes from setting), so I cannot be absolutely sure of their identity. Still, after looking at a diagram I believe that the middle figure (the one that is entirely green) shows some lines from Magnesium (b1 and b2) and Iron (the E line). I am not entirely sure which is which, however. Also, the top figure probably shows the hydrogen-beta line (Fraunhofer F line -- one of the Balmer series lines).

More information on these lines can be found here. There are sites out there with far more detailed databases of solar lines (thousands are known), but this diagram is simple enough for those of us with very basic equipment. A very high resolution spectrum can be obtained from the NOAO (National Optical Astronomy Observatory).

When conditions are more favorable and this instrument is in better condition I will post a more detailed set of observations and some photos of the instrument itself.

It is my quasi long-term goal to put together a system for astrophotography. This consists of three major units: a telescope, a telescope mount, and a CCD camera. Unfortunately, this equipment is very expensive. The mount that I selected -- and the first piece of equipment in this set -- was a Takahashi NJP – about $7500 retail, but on July 22, 2007 I found one that included a Meade Giant Field Tripod on Astromart for about $5500. After corresponding with the seller, I sent a check on July 31.

Needless to say, I was very anxious as I waited at home for the UPS driver to deliver it on August 9. After unpacking the boxes (it was shipped in 6 packages) I was not at all pleased with what I saw. The Temma (electronics) control box was severely dented and, although it was not obvious at the time, the right ascension motor was also destroyed.



The seller (who will remain anonymous) was very helpful in contacting UPS and filing a claim, and on August 14 UPS was supposed to contact me to schedule an inspection visit to photograph the damage. They eventually did call and visited on August 16. The inspector was noncommittal when asked about whether or not the claim would be paid – for the most part she just took photos. After this, there were no developments for quite some time, and what correspondence did occur was between the seller and UPS.

In any case, I was now left with a non-functional and very expensive mount, so repairing it was the only real option. I had it crated in wood and shipped (via FedEx this time) back to Texas Nautical Repair on August 21 – it arrived on August 24 and repairs began.

On September 4 I received an email from the seller indicating that UPS had initially denied the claim due to insufficient packaging (apparently having it double-boxed with the inner “box” consisting of a $400 Pelican case is considered “insufficient”), but that he intended to fight that determination. I do not know exactly what happened next, but on September 10 I received another email from the seller indicating that the claim would be paid by UPS. On October 17 the seller mailed me a check to reimburse me for the cost of shipping the mount back to Texas for repair (which UPS reimbursed him for, I understand).

On October 22 the repairs were finished (costing about $1250, which the seller paid and UPS reimbursed) and Art at Texas Nautical Repair shipped the mount back to me via UPS. I was not particularly happy with this choice of companies, but it arrived intact on October 25. Due to a 3-week business trip to Japan on November 3, I did not do any extensive testing other than to verify that the mount was physically intact.

So, after 4 months of waiting, I have a working NJP mount. The seller in this case was incredibly helpful, and the whole experience didn’t cost me anything extra in the end. Still, I will always have a deep-seated distrust of UPS due to this incident, and I intend to avoid doing business with them whenever possible. Had the seller not been willing to stand up to their initial denial of the claim, I would have been out $1250 due to their gross mishandling of such a valuable item.