THE SOUTHWORTH PLANETARIUM 207-780-4249 www.usm.maine.edu/planet <http://www.google.com/url?q=http%3A%2F%2Fwww.usm.maine.edu%2Fplanet&sa=D&sntz=1&usg=AFQjCNHulkHuLP13bOG2PkNrPazsGWFs2A> 70 Falmouth Street Portland, Maine 04103 43.6667° N 70.2667° W Altitude: 10 feet below sea level Founded January 1970 Julian Date: 2459113.16 2020-2021: XIV THE DAILY ASTRONOMER Monday, September 21, 2020 Remote Planetarium 92: Week 20 Quiz We apologize for the delay! The quiz pertaining to last week's Remote Planetarium classes is below. Tomorrow we continue our trek through the Universe by entering the Local Group of Galaxies. *1. Which one of the following galaxy types is not included on Hubble's "Tuning Fork" diagram?* a. Ellipticals b. Spirals c. Barred Spirals d. They are all included on the Hubble Tuning Fork *2. What is the difference between an E0 and E7 galaxy?* a. an E0 galaxy is closer to Earth than an E7 galaxy b. an E0 galaxy appears redder than an E7 galaxy c. an Eo galaxy appears nearly circular; an E7 galaxy is highly elongated d none of the above *3. What type of galaxy is the Milky Way?* a. elliptical b. spiral c. barred spiral d. lenticular *4. What is the difference between an Sa and Sc spiral galaxy?* a.an Sa galaxy is more tightly bound than an Sc galaxy b. an Sa galaxy less tightly bound than an Sc galaxy c. an Sa galaxy is closer to Earth than an Sc galaxy d an Sc galaxy is closer to Earth than an Sa galaxy *5. An ellipse is a closed curve containing two ____________.* a. vertices b. foci c. co-vertices d. all of the above e. none of the above *6. Lenticular galaxies are __________* a. regions of prodigious star formation b. regions of little to no star formation c. regions of average star formation d. can produce no, a few or many stars depending on the lenticular galaxy's shape. *7. Approximately ______ percent of all known galaxies in the Universe are irregulars.* a. 10 b. 15 c. 25 d. 40 *8. Astronomers divide irregular galaxies into __________ main types.* a. 2 b. 3 c. 4 d. 5 *9. Lenticular galaxies are likely to be intermediate galaxies between:* a. elliptical and spirals b. elliptical and irregular c. irregular and spirals d. none of the above. *10. Lenticular galaxies are sometimes known colloquially as ____________* a. Long galaxies b. UFO galaxies c. Cigar galaxies d. none of the above. *11. The Big Bang, or genesis event, occurred approximately ________ years ago. * a. 5000 b. 10 million c. 11.3 billion d. 13.8 billion *12. Approximately _________________ years after the Big Bang, the first stars formed.* a. 100,000 b. 20 million c. 200 million d. 560 million *13. The Milky Way and Andromeda Galaxies are due to "collide" within ____________ years.* a. 10 - 50 b. 2 - 8 million c. 30 - 200 million d. 4- 6 billion *14. The Milky Way Galaxy is ____________ light years in diameter and consists of ___________ stars.* a. 20,000; 50 billion b. 45,000; 100 billion c. 75,000; 200 billion d. 100,000; 300 billion *15. The black hole in the galaxy's center is approximately ________________ times more massive than the Sun.* a. 1 million b. 2 million c. 3 million d. 4 million *16. What is the difference between the "Andromeda Galaxy" and "Andromeda Nebula?"* a. nothing. These names refer to the same object. b. the Andromeda Galaxy refers to a grand spiral galaxy about 2.2 million light years from the Milky Way; the Andromeda Nebula refers to a supernova remnant about 2,300 light years away c. the Andromeda Nebula is the largest known gas cloud within the Andromeda Galaxy d. the Andromeda Nebula was the gaseous body out of which the Andromeda Galaxy formed. *17. We know our solar system is not located within the galaxy's center because ___________ are not found in all directions.* a. galactic (open) clusters b. globular clusters c. spiral arms d. dark nebulae *18. Our solar system is approximately _____________ light years from the galactic nucleus.* a. 10,000 b. 23,000 c. 44,000 d. 103,000 *19. _________ waves are thought to be responsible for the formation of our galaxy's spiral arms.* a. gravity b. density c. momentum d. p-waves *20. Whose verse translations of the Homeric epics is considered the "Platonic Ideal of Homeric translation?"* a. Alexander Pope b. Robert Graves c. William Wordsworth d. Christopher Wren ANSWERS *1. Which one of the following galaxy types is not included on Hubble's "Tuning Fork" diagram?* d. They are all included on the Hubble Tuning Fork One will find elliptical galaxies, spiral galaxies and barred spiral galaxies along the Hubble Tuning Fork diagram. Lenticulars and irregular galaxies are also included in the expanded version. *2. What is the difference between an E0 and E7 galaxy?* c. an Eo galaxy appears nearly circular; an E7 galaxy is highly elongated Elliptical galaxies are classified according to degree of elongation. The range extends from E0 for circular elliptical galaxies to E7 for highly elongated ellipticals. *3. What type of galaxy is the Milky Way?* c. barred spiral The center of our home galaxy contains a large bar of stars. *4. What is the difference between an Sa and Sc spiral galaxy?* a. an Sa galaxy is more tightly bound than an Sc galaxy. Spiral galaxies are classified according to the "tightness" of their spiral arms. Sa galaxies are tightly bound; Sc galaxies are more open. See image below. [image: 1. Spiral Galaxies Type Sa Type Sb Type Sc.jpg] *5. An ellipse is a closed curve containing two ____________.* d. all of the above. An ellipse contains two foci, vertices and co-vertices as seen in the image below. [image: CNX_Precalc_Figure_10_01_0042.jpg] *6. Lenticular galaxies are __________* b. regions of little to no star formation Lenticular galaxies are disc galaxies that contain little to no gaseous material and so are not active regions of star formation. *7. Approximately ______ percent of all known galaxies in the Universe are irregulars.* c. 25 Irregular galaxies do not fit into any of the other galaxy categories. However, they comprise about one-quarter of all galaxies in the cosmos. *8. Astronomers divide irregular galaxies into __________ main types.* b. 3 Irr-I, Irr-II and dlrr. *Irr-I:* might contain some structure, though not enough to place it on the Hubble Tuning Fork diagram *Irr-II:* devoid of any structure *dlrr*: a dwarf, irregular galaxy. *9. Lenticular galaxies are likely to be intermediate galaxies between:* a. elliptical and spirals Galaxies evolve. Lenticulars are early-type galaxies in states of transition. *10. Lenticular galaxies are sometimes known colloquially as ____________* b. UFO galaxies Lenticular galaxies resemble the disk-like ships that are popularly called "UFO's." *11. The Big Bang, or genesis event, occurred approximately ________ years ago. * d. 13.8 billion According to current cosmological models, the Universe began about 13.8 billion years ago in an event dubbed "The Big Bang." Everything within the Universe (space, time, matter and energy) arose in this event. *12. Approximately _________________ years after the Big Bang, the first stars formed.* d. 560 million The first generation of stars formed about half a billion years after the Big Bang. By that time, the Universe consisted primarily of hydrogen and helium. From this material stars coalesced and through a series of complex fusion reactions created heavier elements. *13. The Milky Way and Andromeda Galaxies are due to "collide" within ____________ years.* d. 4- 6 billion In the distant future, our home galaxy will merge with the Andromeda Galaxy to produce a mega-galaxy consisting of more than one trillion stars. *14. The Milky Way Galaxy is ____________ light years in diameter and consists of ___________ stars.* d. 100,000; 300 billion The Milky Way Galaxy is a grand spiral galaxy, larger than any other galaxy in the Local Group except Andromeda. If the Milky Way Galaxy were reduced to the size of North America, our solar system would fit inside a coffee cup. Earth would only be visible through a microscope. *15. The black hole in the galaxy's center is approximately ________________ times more massive than the Sun.* d. 4 million Every spiral and elliptical galaxy contains a supermassive black hole in its center. The Milky Way's central black hole is four million times more massive than the Sun. Astronomers can estimate its mass by measuring the velocities of stars around the center. The more massive this body, the faster the stars in its proximity will move. *16. What is the difference between the "Andromeda Galaxy" and "Andromeda Nebula?"* a. nothing. These names refer to the same object. The term "Andromeda Nebula" dates back to the time when the Milky Way Galaxy was believed to have been the only galaxy in the Universe. The Andromeda Nebula was then thought to have been a vapor cloud within our home galaxy. It turned out to be a galaxy well outside the bounds of the Milky Way. *17. We know our solar system is not located within the galaxy's center because ___________ are not found in all directions.* b. globular clusters The old, massive star clusters congregate around the halo, the spherical region surrounding the Milky Way's nucleus. Astronomers have only observed these clusters in and around the Sagittarius region. These observations lead astronomers to conclude that our solar system is positioned well away from the nucleus. *18. Our solar system is approximately _____________ light years from the galactic nucleus.* b. 23,000 The Sun and its attendant bodies are about 2/3 of the way between the nucleus and outer part of the galaxy. Our solar system is along the Orion spur, an off-shoot from the Orion-Cygnus Arm. *19. _________ waves are thought to be responsible for the formation of our galaxy's spiral arms.* b. density Density waves are compression waves, like those that transmit sounds. Spiral arms were believed to have formed around the "crests" of these waves. *20. Whose verse translations of the Homeric epics is considered the "Platonic Ideal of Homeric translation?"* a. Alexander Pope So, we included only mythology question. British poet Alexander Pope (1688-1744) translated Homer's epics "The Iliad" and the "Odyssey." His translations are considered among the best. Some scholars argue that his English translations are unsurpassed. To subscribe or unsubscribe from the Daily Astronomer: https://lists.maine.edu/cgi-bin/wa?SUBED1=DAILY-ASTRONOMER&A= <https://lists.maine.edu/cgi-bin/wa?SUBED1=DAILY-ASTRONOMER&A=1>