Category: Astronomy

Exploring the cosmos

A School Star Party

Something was wrong… it was not raining.

Four previous times we have attempted to do this, hold a star party for the students of Waikoloa Elementary School. Four times it has been either cloudy, or outright raining. Yes, raining in one of the driest areas of the island, a place that gets, maybe, ten inches of rain each year.

We even had clear skies!

It was a great event, perfect skies, several big telescopes, and hundreds of eager eyes.

Mr. O and the Kids
Students of Waikoloa Elementary School enjoying the night with Mr. O
Early in the evening I was worried that it was all for naught. About 7:30pm we were all set up and had a total of two guests, a mother and her daughter. They were getting a private showing of the sky at my telescope, with good views of Saturn, star clusters and nebulae. But where was everyone else? Classroom announcements had been made. Flyers had been sent home with every student. Two people?

They hit us just after 8:00pm, a steady stream of students and parents drawn to see the sky. I would guess that well over two hundred folks came by the star party. The skies in Waikoloa are wonderful for this sort of thing. Nice and dark, with the summer Milky Way glowing brightly overhead. We slewed from globulars to nebulae, to binary stars. Steady lines of folks waiting to look through each telescope. I have never gotten tired of the reaction when someone sees something spectacular through the eyepiece for the first time.

Cliff used his 24″ ‘scope to hunt down the new supernova in M101, visible as a small star like object at the edge of a faint halo. I was wondering which star was actually the supernova. Examining some photos afterwards I realized we were looking at the correct object. It will be interesting to observe this event over the coming week, as a nearby Type 1A supernova it should get quite bright.

My thanks to the guys from WHAC who supported this event. Mr. O, our school contact had everything perfectly arranged, from the flyers, to insuring the lights and sprinklers were off for the night. It was a great event, I expect we will do this again.

Astronomy Q&A

I get email. Unlike some more controversial folks on the web, this does not normally contain hate mail. My messages are usually fun to read. A regular feature of my mail are astronomy newcomers asking the usual questions…

Hi,

I found your site while hunting around Google for an answer to a question. I wonder if you can help.

My telescope was bought during the winter of 2011. I’m new to hunting and finding stars and planets. This morning like many mornings I was out and about around 5:38 am. I live in the northern hemisphere, on a farm. As always I look around for any stars that might still be out before the Sun rises fully. If I look hard enough I can find a few. One always sticks out. It is to the south, high in the sky and very bright. At first I thought it was Saturn, but my star chart tells me Saturn would be closer to SSW at 5:35 in the morning. Being I’m not using a compass, I wonder if indeed I’m not facing true south. I’ve read it could be Sirius, but I don’t believe it is, maybe I’m wrong.

Are you able to give me some idea’s as to what star I’m looking at?

Thanks, and I hope you don’t mind the crazy question.

One more question. In the spring when I was looking at Saturn I could have sworn I was able to see the rings of Saturn tilting, or better stated moving up and down for lack of better wording. Am I correct in that? I am using a Celestron AstroMaster 114. Not the best but it was affordable, just in case star gazing was not for me.

Cheers,
[Name withheld]

Saturn 22Apr2010
Saturn with Titan above, Philips ToUcam PCVC740K on a C-14 w/2x barlow, stack of 550 frames selected from 1200
With a message like that I just have to respond…

[Name withheld],

Looking up whenever you walk outside is a good sign that you are indeed a stargazer at heart. I find myself doing the same any time I am under the night sky, even when walking across a supermarket parking lot I look up to see what stars or planets are visible.

Learning the sky simply takes a curious mind and a little experience. The patterns of the sky are regular and predictable. Keep learning and you will be able to recognize any bright star any time you step outside.

A remarkable early morning star could indeed be Sirius this time of year. This is the brightest visual star in the sky and can be quite striking. A quick look at the brightest star in the constellation Canis Major will also reveal the bright constellation Orion just to the north.

Each morning a fixed star like Sirius will rise about four minutes earlier, about one degree higher in the sky each day. The cycle repeats each year with the same stars visible in the same positions in the same season. By fall Canis Major and Orion will be in the evening sky and they will disappear into the Sun’s glare come spring.

Your description of Saturn is interesting… The angle of Saturn’s rings does change, but only over the months and years as the the Earth and Saturn orbit the Sun and the angle from which we view the planet changes.

It may not have been your imagination either. You may have been experiencing what astronomers call poor seeing. This is due to the air above, through which we view the heavens, distorting the light. the effect is the same thing that gives stars a twinkle or can cause the image to shimmer over a hot road. Normally the effect will blur the image slightly, coming and going with moments of clarity. When really bad the image of a star or planet can move about in the eyepiece. I have seen Jupiter look like a bouncing rubber ball under bad seeing conditions.

Keep looking up!
Andrew

Just a Little Nudge

One of the tasks I have helped with on the K1 AO Laser is aligning the Launch Telescope Assembly (LTA). This is not so much an electrical engineer’s task, but a mechanical one. So how did I end up with the task? Simple, I was present the first time it was done. Since the mechanical engineer who was first responsible has now left the observatory, I get the job by default. Just the way things work around here.

The launch telescope is a small telescope, about 0.5 meter in aperture, that projects the laser into the sky. Mounted behind the secondary mirror of the Keck 1 telescope, it must be precisely aimed to exactly the same spot in the sky the main telescope is aimed.

Launch Telescope Adjustments
Adjusting the mounting of the K1 Launch Telescope
The procedure is not all that difficult. Mount two dial indicators in place, restrain the motion by using wooden wedges or a really big c-clamp, loosen the bolts, make the adjustment, tighten the bolts. No problem, right? The challenge is to move the large assembly just a few thousandths of an inch and have it stay exactly where you want it while re-tightening the bolts.

In practice this adjustment is about one to two hours crouched in the secondary assembly of the Keck 1 telescope. Each time the bolts are tightened the assembly moves about 10-15 thousandths of an inch. Thus I have to guess how much to offset the measurement so it ends up correct when the bolts are tight. It takes anywhere from three to five repetitions to get right sometimes.

This is where I curse the mechanical engineer who dreamed up the mounting for the launch telescope. I look at the dial indicators, shift my stance against the cold steel to stop the cramping, loosen the bolts and try again.

The last adjustment was a mere 0.004″ (four one-thousandths of an inch) to move the pointing about 30 arc-seconds on the sky. I am now only about 10 arc-seconds from the optical axis. Keep in mind that a single arc-second is 1/60th of an arc-minute, which is in turn 1/60th of a degree. Ten arc-seconds is pretty good, but we want closer. Here I go one more time…

Postcard from the Summit – In The Hall

Another processed infrared image from Mark Devenot. This time the subject is an everyday scene inside the facility with some of the crew standing in the hallway. The odd feature behind them is actually the large doors that lead into the Keck 1 Telescope dome. Everything looks much different in the thermal infrared…

IR Hallway
In the hallway, a mid wave infrared image taken with a FLIR PM250 camera, with artist effects added in Photoshop, photo by Mark Devenot

Oops, a little too much power there…

How powerful is the K1 AO laser?

For someone who has lately been used to working around relatively harmless power levels, beams of a few milliwatts, this is a reminder that lasers are potentially very dangerous. With a milliwatt power level beam there is no danger in getting a hand in the beam, be mindful of your eyes, but otherwise not a lot of concern. This is vastly different, beam power here is measured in tens of watts… The bright yellow beam looks so innocent, appears so harmless. Give that beam a chance, a momentary slip, and it will burn you… badly.

Anything in the beam is at risk, even components we thought were robust enough to withstand the power levels. In this case a reflective ND filter that was to reflect most of the beam into a beam dump, allowing a small amount to continue up the beam train for use in alignments. So much for the ratings on the manufacturer’s data sheet, the beam punched through the coating and even started to melt the glass…

Burned Filter
A reflective ND filter burned through by the K1 AO Laser

Postcard from the Summit – Red Bow

Waimea is a place of rainbows. So common are they here it is a rare day that goes by without at least one rainbow.

But what does a rainbow look like at sunset? When the Sun’s light is reddened by passage through so much air and haze. The bow will begin to lose all color except for red, this creates a red bow…

Red Bow above Mauna Kea
A snow covered Mauna Kea at sunset as seen from Wiamea, with a bit of a red sunset bow above the western slope

SCRAM!

Shut it down! Shut it all down!

I get home from shopping in Kona and unloading a pile of groceries from Costco. Looking forward to a relaxing Saturday evening. That changed when I checked my e-mail.

Keck Webcam 4 Jun 2011
Several inches of snow in the Keck Telescope parking area on June 4th!
Oh joy…

Much of the systems on the summit are automated, up to and including sending e-mails when thing go wrong. The system works pretty well at letting the engineering staff know when attention is needed. The automated messages do tend to bomb a person’s inbox when it really goes bad.

Dozens of warning messages have flooded my inbox…

WARNING! K2AO temps are warm! dmrackTemp=45.42 degC, enclosTemp=37 degC

Ugly numbers indeed! 37°C is about 100°F in the AO electronics room. I have no choice… shut it down. Messages from MKSS indicate that the power lines have been hit by lightning and the power is out to the summit. The backup power is holding out, but the glycol cooling system is off. Without cold glycol flowing in the lines many of the rooms are without cooling systems to take away the heat generated by all of the computers and other electronics.

Continue reading “SCRAM!”