02Lab_Observing-the-Night-Sky-2A_red

.docx

School

Montgomery College *

*We aren’t endorsed by this school

Course

101

Subject

Astronomy

Date

Oct 30, 2023

Type

docx

Pages

Uploaded by JudgeBat3549

M ONTGOMERY C OLLEGE – R OCKVILLE A STRONOMY 101 ASTR101 Laboratory 2 – Observing the Night Sky 1 Name: AAditya Rana All Astronomy begins with looking at the sky. For thousands of years humans have watched the sky at night, carefully noting the positions of the stars and planets, and how they change as the hours, days, and months go by. Indeed, until modern times, knowing the sky was a matter of life and death. If a farmer misjudged when he or she should plant his or her crops, or if a nomadic hunter-gatherer misjudged when to start moving south for the winter, the result was certain death. To make observations of the night sky easier over the millennia, people developed various names for both stars and groups of stars, the latter of which are called constellations . In this assignment we’ll use Stellarium to observe the sky tonight. We’ll see what stars and constellations are visible, and try to understand how they move as the hours pass. PART A Start Stellarium . Make sure you are observing from Rockville by opening the Location window (Find the Location icon at the left-hand side of the screen, or simply press the F6 key.) Enter Rockville in the search bar, and then click on Rockville, United States. Close the Location window. Zoom out until the Field of View (indicated by FOV in the Information Bar at the bottom of the screen) is about 180° . Then drag the horizon around until the sky is centered on the screen and North is at the top. You should see the sky as a complete circle, centered on your screen, with the horizon (North, South, East, and West) forming the edge of the circle, and the zenith at the center. Turn the atmosphere off (if it is on) by pressing “ A” . You should see a sky full of stars (and perhaps some planets and asteroids). Pause the time with the time control buttons or simply press “7”. Set the date for today, and the time for 12:00 AM (0:00 in “military time”) by clicking on the Date/Time icon on the left-hand side of the screen (or by simply pressing the F5 key) and adjusting the time. As you click on various dots in the sky, (almost all of which are stars), a cross hair appears over your selected star, and information about the star appears in the 1 Last edit Spring 2022. 1

ASTR101 L ABORATORY 2 upper left-hand corner of the screen. There is a lot of information here, including, on the first line, the various names of the star. The first name listed in that top line is the common name of the star. Let's start with those names. Find the three brightest stars in the sky (the three biggest dots) and click on them one at a time. Name sure the object you have selected is actually a star! It can be a double star or a pulsating variable star, but do not list planets, asteroids, or other objects. In each star's information listing, nearer to the bottom, the distance to the star is given in light years, abbreviated “ly” (a light year is the distance light travels in one year). Record the names and distances to your three stars. You do not need to include the number after the ±. This is just an error bar on the distance. Please use red font for answers. Star Name Distance (ly) Altair 16.73 Capella 42.80 Vega 25.04 You might recognize some of these stars. Each of these stars is part of a specific constellation, or area of the sky assigned to a particular mythical character, object or animal. To see the stick-figure outlines of the constellations, press the “ C” key on your keyboard, or click on the Constellation Lines button in the toolbar at the bottom of the screen. Lines appear connecting the brightest stars in each constellation. To show the names of the constellations, press the “ V” key on your keyboard, or click on the Constellation Labels button in the toolbar at the bottom of the screen. Many of these constellation names should also be familiar. Name the three constellations that contain your three stars: Star Name Constellation Vega Lyra Altair Aquila Capella Auriga As you can see, it’s hard to tell where in the sky one constellation ends and the next one begins. To see the official borders between constellations, press the “ B” key on your keyboard. The constellations' boundaries appear as red dashed lines. These borders are like the borders between states. Astronomers have agreed to define 2

ASTR101 L ABORATORY 2 them precisely, so that every spot in the sky (and hence every star) is in exactly one constellation.cv To see pictures of the mythical characters associated with each constellation, press the “ R ” key on your keyboard or click on the Constellation Art button in the toolbar at the bottom of the screen. (It might be useful to turn the art off by pressing “ R ” again.) Change the time to 9 PM on March 20, 2021 (open the Date/Time window or press the F5 key), then answer the following questions (It may be easier to see the constellations if you zoom in or out and drag the sky around to re-center it): What constellation is just above the Southern horizon? Puppis What constellation is just above the Northern horizon? Draco What constellation is closest to the Zenith? Gemini Open the Search Window (type CTRL-F or press F3 ) to help you find the following objects. Remember, once you've typed the name of an object in the Search window, hit Enter and that object will be selected and centered on screen. If the object is hidden by the Earth, press the “ G ” to key to hide the ground. Find the constellation Ursa Major . Name two stars it contains. (Remember, click on a star to see its name.) Dubhe Alioth Find the star Shedar . What constellation is it in? Cassiopeia Find the star Alderamin . Look at the information that appears on screen about it. How far away is Alderamin in light- years ? 49.05  Display the labels of the planets and the bright stars by going to the SSO tab within the Sky and Viewing Options window.  Make sure “ Solar System objects ” is checked (or simply press the P key). 3

ASTR101 L ABORATORY 2  Close the Sky and Viewing Options window. Zoom back out to see the whole sky.  Make sure the constellations are displayed. If they aren't, press C , V and B until you see them, their names and their borders .  Move the date to March 20, 2022 and set the time to midnight (0:0:0) . Is the Moon out right now? yes If so, what constellation is it in? Virgo Set the date and time to December 24, 2020 at noon . Note the change in year! Again, make sure that you can see the whole sky by zooming out and dragging the sky around. Find the Sun . What Constellation is it in? Sagittartius Keep the date at December 24, 2020 , but set the time for midnight . Find the Moon in the sky and center it. Please make sure your constellation boundaries are on ! What planet is the Moon near? Mars What constellation is the Moon in? Pisces What constellation is the Moon in on December 26, 2020? Aries Remember, rather than re-entering the new date information each time, you can simply press the “=” key to advance the time by one day. What constellation is the Moon in December 27, 2020? Taurus What about December 28, 2020? Taurus 4

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version