Bellwork 9/13 Please hand in:  Old bellwork sheet (if you haven’t already)  Timeline activity Safety contracts Then, grab a new bellwork sheet  NASA receives billions of dollars for space exploration and research. In your opinion, is it worth it? Why or why not?

Quick Discussion In a small group of 3-4, please discuss the following questions and outline your answers on a whiteboard What information did you find interesting or compelling? What did you have questions about? Is studying space worth the money we spend? Please, be prepared to share out what your group discussed.

Bellwork 9/15 Happy Friday!!  In your own words, what causes the phases of the moon?

Announcements Today: Finish Modeling Lab & Discuss, Begin Constellations and Positions Tuesday 9/19: Lab Quiz (2 questions), Celestial Sphere computer simulation Thursday 9/21: Stellar Parallax notes & activity Monday 9/25: Review, Begin Unit 2 Wednesday 9/27: Unit 1 Test

Lab Grade 3 components: Working in the lab & collecting data Working through the analysis questions Lab Comprehension Quiz  These will be short (1-3 questions) and will be very similar to the lab analysis questions

Modeling Lab

Pareidolia--the tendency to perceive a specific, often meaningful, image in a random or ambiguous visual pattern

People of the past used this phenomenon to designate locations & positions in the night sky. Why would they care to do that?

Constellations A recognizable pattern of stars in the sky Used to separate & locate regions of the sky 88 constellations They were not all designated at one time

Constellations Bayer System System of labeling stars First for Brightness Using Greek alphabet α Brightest β 2nd Brightest And so on

Celestial Sphere Stars appeared to move around a fixed point and rotate around Earth We now know that these “star trails” are due to the Earth’s rotation…not the stars’.

Celestial Meridian: Divides the sky in half from north to south. Zenith: Bisects the meridian This point never changes on the celestial sphere, but from the observers’ point of view, the stars at the zenith change “Actual” zenith vs. “local” zenith How do we tell “what’s what”?

Locating Objects in the Sky: There are 2 ways to look at it… 1. Equatorial system of location Two location components Declination – the angular distance north or south of the celestial equator Measured in degrees  Right ascension – the angular distance measured eastward along the celestial equator from the position of the vernal equinox Measured in hours & minutes 

Right Ascension (or "RA") and Declination (or "Dec") are global coordinates any particular star has the same RA and Dec for all observers on Earth, and that position remains the same, night after night.

Locating objects in the night sky: Local Coordinates 2. Altitude and Azimuth local coordinates each observer sets up his own reference frame Altitude and Azimuth of a given star will change over just a few minutes as the star appears to move across the sky

Ecliptic Zodiac The apparent path of the sun through the stars The broad belt of constellations that lie along the ecliptic 12 total constellations

Anatomy of a Planisphere: Inner ring: time of day Declination: Degrees in “viewing window” Middle ring: Months & Days Outer ring: Right ascension (hours & minutes)

How to use a Planisphere Set the planisphere to the correct day and time Make sure you’re holding the planisphere in the correct orientation  “East horizon” on the left, “West horizon” on the right Find the Declination Find the Right Ascension (a straight edge can be helpful with this)

What the heck am I looking at?!? Horizon (looking South) Horizon (looking North) Directly overhead…or the Zenith

Planisphere Practice: What is the RA & Dec. of Arcturus? (near constellation Bootes) RA: ~14hr 15min Dec: ~+20⁰

Planisphere Practice: What is the RA & Dec. of Betelgeuse? (in constellation Orion) RA: ~6hrs Dec: ~+8⁰

Planisphere Practice: Set your planisphere to September 16th at 10:00pm. Name a constellation that is RISING (on the East Horizon). Taurus Perseus Aries Ect…

Planisphere Practice: Set your planisphere to January 12th at 6:00pm. Name a constellation that is SETTING (on the West Horizon). Sagitta Cygnus Capricornus Ect…

Planisphere Practice: Set your planisphere to February 28th at 8:00pm. Name a constellation that is close to its ZENITH.  Zenith = bisecting line of the meridian… SO divide your “window” in half horizontally and choose a constellation at that bisecting line Gemini, Auriga, Camelopardalis

…There is more than one answer here! Bellwork 9/15 How do astronomers communicate the location of objects in the celestial sphere? …There is more than one answer here!

Anatomy of a Planisphere: Inner ring: time of day Declination: Degrees in “viewing window” Middle ring: Months & Days Outer ring: Right ascension (hours & minutes)

What the heck am I looking at?!? Horizon (looking South) Horizon (looking North) Directly overhead…or the Zenith

Planisphere Practice: What is the RA & Dec. of Pollux? (near constellation Gemini) RA: ~7hr 45min Dec: ~+28⁰

Planisphere Practice: Set your planisphere to July 15th at 9:00pm. Name a constellation that is RISING (on the East Horizon). Pegasus Delphinius Aquarius Capricornus

Planisphere Practice: What is the RA & Dec. of Sirius? (near constellations Monoceros & Canis Major) RA: ~6hr 45min Dec: ~-17⁰

Planisphere Practice: Set your planisphere to April 15th at 11:00pm. Name a constellation that is SETTING (on the West Horizon). Gemini, Canis Minor, Cancer, Auriga

Planisphere Practice: Set your planisphere to February 28th at 8:00pm. Name a constellation that is close to its ZENITH.  Zenith = bisecting line of the meridian… SO divide your “window” in half horizontally and choose a constellation at that bisecting line Gemini, Auriga, Camelopardalis

Planisphere Practice: Set your planisphere to October 15th at midnight. Name a constellation that is close to its ZENITH.  Zenith = bisecting line of the meridian… SO divide your “window” in half horizontally and choose a constellation at that bisecting line Cassiopeia, Perseus

Planisphere Practice: Set your planisphere to March 20th at midnight. Name a constellation that is close to its ZENITH.  Zenith = bisecting line of the meridian… SO divide your “window” in half horizontally and choose a constellation at that bisecting line Ursa major