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What You Will Do on Day 5
This field trip will visit The Haystack Observatory where we will tour the facility and then meet with Dr. Arthur Neil to discuss his current work with Geodesy and also GPS. Depending on research schedules, Haystack's Small Radio Telescope (SRT) will be demonstrated. We will then visit Alden Planetarium at Worcester's EcoTarium to view an astronomy program covering the night sky visible from the local latitude. We will return to the hotel for a late lunch and down-time in preparation for an evening viewing of the night sky.
The purpose of this trip is to become familiar with the different aspects of Astronomy and to actually make observations using both radio and optical telescopes.
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What You Will Need For Day 5
• Picture ID
• Drinking Water, Snacks
• Rain Gear, Extra Socks
• Insect Repellent
• Planisphere, Binoculars
• Flashlight
• Blank Sky Charts (provided)
Fees (per person):
• $10 - EcoTarium Admission (Members Free)
• $350 - Alden Planetarium Admission
• $5 - $10 for lunch
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Field Trip
MIT Haystack Observatory
Stop #1
(~2 hours)
IMAGE 1 - MIT Haystack Observatory
From: MIT Haystack Website
The Haystack Observatory uses radio astronomy to study the Earth's atmosphere and the motions of the Earth's tectonic plates, the Sun, space weather, and Cosmology - the study of the origin and structure of the Universe. Haystack provides resources to teachers, students, and clubs, through a grant from the Nation Science Foundation, to introduce radio astronomy, geodesy, and atmospheric science to the public.
Construction on the Haystack Observatory began in 1960 and operations commenced in 1964 with observations of Moon, Mercury, Venus & Mars. This 37 meter-wide radio telescope was used to examine the surface of both the Moon and Mars to evaluate proposed landing sites for the Apollo Program and the Viking Mission, respectively. Haystack was the site where the "fourth test" of Einstein's General Theory of Relativity was successfully completed.
While at the observatory, we will take a guided tour, including a demonstration of how the radio telescope is moved to a particular coordinate, and then learn how radio astronomy at Haystack is used in:
Geodesy - tectonic movement of the lithospheric plates:
GPS - how atmospheric conditions can affect the accuracy of GPS signals.
[Click Image to Enlarge]
IMAGE 2 - Approach to Haystack
Stephen C. Daukas, June, 2006
IMAGE 3 (right) is a view of the 18-meter wide Westford Radio Telescope that is one of many radio observatories in a global network of radio telescopes gathering data on Earth's plate motions. This network is an example of interferometry - see IMAGE 1 in the background reading - known as VLBI, or very long baseline interferometry.
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IMAGE 2 (left) shows the approach to the Observatory and the radio telescope's geodesic radome. This particular telescope is visible in the upper-left of IMAGE 1 (above).
[Click Image to Enlarge]
IMAGE 3 - Haystack - Westford Telescope
Stephen C. Daukas, June, 2006
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IMAGE 4 - SRT
From: MIT Haystack Website
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Small Radio Telescope (SRT)
One of the instruments we will examine is the Small Radio Telescope (SRT). IMAGE 4 (left) shows one example of a do-it-yourself SRT built using a kit from CASSI Corp. that includes everything necessary to operate the telescope. This kit is specifically designed to provide access for amateur astronomers and students to radio astronomy. The SRT uses a standard 7.5 foot satellite TV dish (not the two-foot digital TV dish) mounted on top of a computer-controlled motorized Azimuth/Elevation mount. Included software controls the antenna and selection of source coordinates.
Haystack provides information, guides, and exercises for using the SRT. For example, the SRT can be sued to detect solar flares, or to measure the Galaxy's rotation, or to measures the Sun's flux density over the 28 day solar rotation. IMAGE 5 (below) shows a Solar Flux data plot from the SRT compared to NOAA data from the same period.
Additionally, the SRT can be used for interferometery with two or more antennas. Haystack provides a complete system (motherboard, USB 2.0, Linux, GPS) capable of performing real-time interferometry.
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IMAGE 7 - SRT Solar Flux
From: Haystack Observatory Web Site
Geodesy & Atmospheric Science
Geographically distributed radio telescopes (VLBI) are used to detect the motion of Earth's tectonic plates. This motion can be directly measured by several techniques. Haystack has been tracking the distance between an antenna in Germany and Westford for ten years. The data show that North America and Europe are moving away from each other at a constant rate of ~17 millimeters per year. The same techniques show the relative plate motion at the San Andreas transform fault in California to be moving at the rate of ~5 centimeters per year. In addition to Tectonic measurements, the "wobble" of Earth's rotation about its axis can also be determined, as well as relating time (atomic clock) to Earth's rotation.
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Researchers at Haystack are also involved with the study of the climatology of the various layers of the atmosphere and how space weather interacts with our atmosphere.
How space weather affects the accuracy of the constellation of GPS satellite signals as they descend through the layers of Earth's atmosphere will be discussed during or visit. For example, large magnetosphere/ionosphere storms studied using Millstone Hill radar (IMAGE 8 right, IMAGE 9 & IMAGE 10 below) identified the magnitude of these events and the consequences to the middle latitudes over the United States.
Depending on the space weather / atmospheris interactions on a given day, accuracy of GPS receivers on the ground will vary. Understanding these variations is important and must be taken into account for those GPS applications requiring great accuracy.
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IMAGE 8 - Millstone Telescopes
From: MIT Haystack Web Site
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[Click Image to Enlarge]
IMAGE 8 - Millstone Telescope
Stephen C. Daukas, June, 2006
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[Click Image to Enlarge]
IMAGE 9 - Millstone Telescope (fixed)
Stephen C. Daukas, June, 2006
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EcoTarium Museum of Science & Nature
Alden Planetarium
Stop #2
(~2 hours)
IMAGE 10 - EcoTarium
From: Jason Papagan, Boston.com (Boston Globe) staff
Our second stop will be a visit to the Alden Planetarium at the EcoTarium in Worcester where we will view the Constellations of the Zodiac program. This ~45-minute program presents a tour of the night sky's constellations and will prove to be a useful primer for the evening's viewing.
After the program, we will have lunch on-site. The EcoTarium offers snadwiches at its Food Pavilion, and has many scenic picnick spots. Additional time is alloted for exploring the EcoTarium's exhibits and trails. the Timescape Trail & Meadow Trail are recommended. The Timescape Trail is a short trail offering interpretive signs highlighting bedrock geology, flora succession, etc., and the changing use of the region over the past 100 years. The Meadow Trail traverses a New England meadow restored to pre-european settlement. Depending on time, the Tree Canopy Walkway offers a first-hand look at the life of a treetop scientist (40 feet up)! You can use the chair harness, if you wish.
Observing the Night Sky
Stop #3
(3+ hours)
IMAGE 11 - Waiting for Night
From: Rogers Obervatory, Northwestern Michigan College Web Site
Our evening will be spent observing the night sky on the grounds of Shrewsbury High School. This is not a particularly dark location, but it is close by and the major constellations are visible with the naked eye. Binoculars will also be used, as will one or two telescopes.
The easiest way to get started observing the night sky is by locating Polaris, the North Star. Once that is located, other stars and Constellations can be located relative to it.
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Polaris is part of the constellation Ursa Minor, also known as the Little Dipper. IMAGE 12 (right) shows the relationship among the Big Dipper (part of Ursa Major), the Little Dipper (Ursa Minor), and the North Star (Polaris). Finding Polaris isn't too difficult, especially when using your planisphere. If you can see the Big Dipper, you can use the two stars of the "dipper" to draw an imaginary line that points to Polaris.
Once you have Polaris located, you can start the evening activity: We will be locating the circumpolar constellations - the constellations that do not set below the horizon.
IMAGE 13 (below) shows how to estimate the angle between objects in the sky. Hold your arm as shown in the image.
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 IMAGE 12, Polaris
From: University of Maine Web Site
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When your arm is fully extended, you can estimate the angle, in degrees, between two objects using your fist and fingers as shown below. Because of anatomical proportions, this will work for a young child as well as for an adult. If you were to use this method to examine the Big Dipper, you would find that it is about 20° wide (tip of handle to lip of ladel) and the two stars that line up to point to Polaris are seperated by about 5°.
IMAGE 13 - Estimating Anglse With Your Hand
From: Columbia University, Astronomy & Astrophysics Web Site
With your planishpere, your bare hand, and your eyes, you can now create a chart of the circumpolar constellations using the blank chart paper provided. You may find the following helpful when creating your chart (all values are reasonably accurate):
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Draco:
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Dec: +80° to Dec: +50°
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RA: 10h to RA: 20h
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Cassiopeia:
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Dec: +50° to Dec: +60°
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RA: 23h to RA: 3h
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Perseus:
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Dec: +59° to Dec: +31°
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RA: 4h 50m to RA: 1h 30m
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Auriga:
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Dec: +55° to Dec: +28°
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RA: 7h 30m to RA: 4h 40m
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Ursa Major:
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Dec: +61° 45' 03.3" to Dec: +44° 29' 54.7"
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RA: 11h 03m to RA: 11h 09m
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Ursa Minor:
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Dec: +89° 15' 50.7" to Dec: +71° 50' 02.5"
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RA 7h 30m to RA 4h 40m
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What star is represented by the first declination given? Can you explain this from your observations?
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Can you fill in the blanks using your observations, the chart you created, and the information above?
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Camelopardalis:
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Dec: +___° to Dec: +___°
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RA: ___h to RA: ___h
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Cepheus:
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Dec: +___° to Dec: +___°
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RA ___h to RA ___h
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IMAGE 14 - Circumpolar Constellations
From: University Corporation for Atmospheric Research Website
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IMAGE 14 (left) is one example of what your final chart might look like.
However, time is against you when making this sort of chart. The Earth continues to rotate on its axis causing the constellation to move across the night sky.
Refer to the Background reading, specifically the section on Astronomical Coordinates to review the basics, and don't worry if this doesn't "click" right away - making a set of observations is the best way to get comfortable with the Celestial Sphere, Declination, and Right Ascention.
Binoculars and optical telescopes are not necessary for the above exercise, but they will allow for better viewing of individual stars. Some of the "stars" in the above constellations are double stars, or not stars at all. We will make the most of the evening by viewing and discussing the night sky, making observations, and locating & viewing other objecs of interest.
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This completes day five of the tour. When we are sufficiently tired, we will return to our hotel, and meet for breakfast at 8:00 AM.
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