Astronomy 110 Laboratory: Observing

WEATHER

The weather in Hawaii is often hard to predict; conditions earlier in the day are not always a good guide. In general, you should be prepared for both outdoor and indoor labs; we will go observing whenever the weather is good, even if it was bad earlier in the day. The links below are helpful in planning observing sessions:

PLANS

If weather conditions permit, we will go to Sandy Beach or Kapiolani Park to observe faint objects including galaxies and star clusters. We will continue estimating magnitudes for beta Lyrae and delta Cepheie. We may continue charting Andromeda and Perseus, and observe spectra of several bright stars. Once Mars has risen high enough, we will record its position and try to observe surface features. If conditions are bad, we will stay at PSB and begin the data analysis for the Variable Star project.

DIRECTIONS

Most observing sessions will be held off-campus in Kapiolani Park. To reach our observing site in Kapiolani Park, you

1. Go SOUTH (downhill) on University Avenue,
2. Turn LEFT onto S. King Street.
3. Follow the signs for Waikiki through the Kapiolani Avenue intersection.
4. At the light beneath the overpass, turn RIGHT onto Kapahulu Avenue.
5. When you reach the Ala Wai intersection, turn LEFT onto Paki Avenue.
6. Continue on Paki Avenue through the Monsarrat Avenue intersection.
7. At Noela Street, turn RIGHT into the parking lot on Paki Avenue.
8. Look for a truck with a `University of Hawaii' sign and State of Hawaii seal.

For a printer-friendly version with map, see the Directions to Kapiolani Park or Google Directions.

To reach our observing site at Sandy Beach, you

1. Take the H1 EAST.
2. When the freeway ends, continue EAST on Kalanianaole Highway.
3. Continue on Kalanianaole Highway past Hawaii Kai, Hanauma Bay, Molokai Lookout, and Blowhole.
4. Turn RIGHT into the Sandy Beach park entrance.
5. Drive through the park to the far end, where you'll find a small parking area with a bathroom/shower building.
6. Look for a truck with a `University of Hawaii' sign and State of Hawaii seal.

LOG BOOK

Observed Venus, Jupiter, and Arcturus with two 8 inch scopes, using 32 mm eyepieces (37.5×) and 14 mm eyepieces (85.7×). Poor seeing due to low elevation and atmospheric turbulence obscured detail on planets. Jupiter was above and to the left of Venus, about one fist-width (10°) apart.

At the park, we set up four telescopes and began by viewing Venus, Jupiter, and Jupiter's four bright moons using 32 mm eyepieces (37.5×) and 10 mm eyepieces (120×). We then reviewed the material on the "Orientation" handout and discussed ways to estimate angles and compass positions of celestial objects. We finished up by observing the Milky Way with binoculars, and used the telescopes to view the double-star system epsilon Lyrae, the globular star cluster M22, and the star-forming nebula M8 (the Lagoon Nebula).

We set up four telescopes with 25 mm eyepieces (48×) and measuring scales, and made our first measurement of the apparent diameter of the Moon. Mare Fecunditatis and Mare Crisium were fully illuminated, while Mare Nectaris and Mare Tranquillitatis were at the terminator. We then attempted to sketch the constellations of Cygnus and Sagittarius, using templates with bright stars plotted. Two problems emerged: (1) the computer-plotted stars are hard to see under field conditions, and (2) it was difficult to orient the templates correctly.

Plans to view the gibbous Moon from Kapiolani Park were canceled due to heavy rainfall.

We set up one telescope with a solar filter and 32 mm eyepiece (37.5×) to view a large sunspot. This spot has an unusual structure, with a sinuous dark region (umbra); most spots are not so complex.

After meeting at PSB, we left for Sandy Beach hoping to get a look at the Milky Way and a few constellations. Although some holes in the clouds allowed glimpses of the stars, we were not able to do any useful observing. After half an hour we packed up and returned to PSB where we did the Simple Telescope lab.

At the park, we began by checking the position of Venus. Thick clouds obscured our view of Scorpius, so we instead charted Cygnus through thin intermittent cloud cover, and estimated magnitudes of its stars. We also previewed some October and November constellations, including Lyra, Cepheus, Cassiopeia, and Pegasus. After about an hour the clouds began to clear and we set up three telescopes to view Albireo (beta Cyg), the Ring Nebula M57, and the globular cluster M15. We charted Sagittarius, estimating magnitudes of stars in the `Teapot', and used binoculars to view the globular cluster M22, the Lagoon Nebula M8, and the star cloud M24. We also viewed the Andromeda Galaxy M32, which was noticeably elongated. Finally, we watched Mars rising through broken clouds.

We started outside of PSB at 6:45 to chart the position and phase of the Moon. We then set up two telescopes with 3× barlows and 25 mm eyepieces (144×) to observe the phase of Venus and measure its apparent size, and finished up at PSB by checking Venus's position. At the park, we charted the constellations Lyra, Cepheus, and Cassiopeia. We began the variable star project, recording magnitudes for beta Lyrae and delta Cephei. We also viewed both of these stars with telescopes; both are easily resolved double stars. Mars became visible just before wrapping up, but clouds cut short an attempt to check its position.

Unstable weather ruled out a meeting in the park. We began by charting the position and phase of the Moon, and recorded a position for Venus. We then did the Parallax in the Lab exercise. Clouds prevented us from observing an occultation at 20:27 HT, but at the end of class we measured the Moon's apparent diameter using two telescopes with 25 mm eyepieces (48×) and measuring scales.

Showers precluded any observing. We stayed indoors and reviewed ongoing observing projects, including the Phases of the Moon, the Shape of the Moon's Orbit, and Planetary Motions. A computer projector was used to display animations of the Moon, Venus, and Mars. After the break we viewed photos of the recent Lunar Eclipse and discussed the Simple Telescope lab and the problem of accurately measuring magnification.

At the park, we began by reviewing constellations and magnitudes. We estimated magnitudes for variable stars beta Lyrae and delta Cephei. After the break, we observed Mars, recording its position for the first time. We set up four 8 inch scopes and one 12 inch. Two of the smaller scopes, with 3× barlows and 25 mm eyepieces (144×), were used to measure Mars's diameter; the other scopes were used to view the planet. The 12 inch scope turned out to be astigmatic, so the best views were obtained with the smaller instruments. Several people succeded in seeing surface features on Mars; Sinus Meridiani and Sinus Sabaeus combined to form an apparent `band' around the planet.

We began by charting the position of Venus, and then sketched Pegasus, the first of November's constellations. We continued estimating magnitudes for beta Lyrae and delta Cephei. Once Mars had risen high enough, we recorded its position and observed surface features; Syrtis Major and Hellas together presented the appearance of an upside-down `Y'.

At PSB, we began by setting up a 10 inch scope with a digital camera and and display to view the occultation of a mag. 8.6 star by the Moon at 19:12 HT. We also charted the position of Venus, and used two 8 inch scopes with 3× barlows and 25 mm eyepieces (144×) to measure its diameter and observe its phase. At the park we set up six 8 inch scopes and the 10 inch and used them to observe and sketch the first quarter Moon. We continued estimating magnitudes for beta Lyrae and delta Cephei. Once Mars had risen high enough we turned the scopes on it and were able to see Mare Tyrrhenum and Mare Clmmerium.

Bob McLaren gave a 30-minute lecture on EM radiation and spectra, and then discussed the use of the spectroscopes. Each student was asked to observe and record the spectra of at least four sources. The sky was very clear and the Moon well up by 8:30, so we got a diameter measurement.

We met at PSB for about 1 hour to measure images of the Moon and complete the data analysis for the project on the Shape of the Moon's Orbit.

REPORTS

Joshua E. Barnes (barnes@ifa.hawaii.edu) Last modified: November 27, 2005 http://www.ifa.hawaii.edu/~barnes/ASTR110L_F05/observing.html