S1: okay um, this is the planetarium and (i'm trying to get this to work here...) this is the evening sky in Ann Arbor as it will look tonight at about, seven P-M. [SU-M: are you serious? ] and the reason we know it's Ann Arbor is because the sky is very blue. and very light polluted if we go out to a rural area, it'll look a little bit darker, and you'll see, probably five times as many stars. so before we get started here uh i'd like to point out a couple of different ways of orienting ourselves in here first of all if you look to the four corners of the planetarium, we see north up here, and west, south, east. and these are the actual directions of the building. so this is actual north if you've got a good sense of, geography if you go outside the building and look in that direction that's north, for those of you who don't have that if you think about where North Campus is, that's north. this point, directly above my head, what do i call that if i'm an astronomer?
SS: the zenith 
S1: the zenith. okay? and we've got a line that runs, from north to south, passing through the zenith what do we call that? 
SS: meridian 
S1: the meridian, and if i've got stars, uh crossing, which way are they gonna cross this way or this way? to my point of view will they move from the east to the west or the west to the east? 
SS: east to west 
S1: east to west. okay if i start here, and i draw a line, all the way around the base of the dome, what's that line going to represent? 
SS: the equator?
S1: um actually, no. 
S2: damn 
SS: the horizon? 
S1: nope and that's because the celestial equator is about here so farther up in the sky. and i'll tell you in a minute why i know that. so what would we be seeing? 
SS: horizon 
S1: horizon okay um so horizon what's the definition of that...? okay, it's a_ okay here's my zenith, and if i go ninety degrees to any side, that's as far down as i can see. so ninety degrees to, any side of the, zenith is the horizon, and the celestial equator, passes, ninety degrees below the North Pole. and how do we know where the North Pole is? what's a good reference point? 
SS: Polaris 
S1: Polaris and how do we find Polaris? 
S3: Ursa Minor (xx) 
S1: Ursa Minor, it's part of Ursa Minor, and what points to it? 
SS: Ursa Major 
S1: Ursa Major. okay and, we find those in the northern part of the sky, [S2: that is a spoon ] we've got, Big Dipper over here can everybody see that? 
SS: mhm 
S1: okay so the Big Dipper_ in winter it's standing on its tail. so the tail's down here, and here's the dipper, and we use these two stars here, to point, to Polaris. now there's actually nothing very distinguished about Polaris it's very dim, and it's not particularly exciting. but, everything in the sky rotates around that because that's very close, to the North Pole. so i'm going to crank this around and hope that you don't get sick. <SS LAUGH> but what you'll want to see is that all the stars that are within a certain number of degrees from Polaris never rise or set what do we call those? 
SS: circumpolar 
S1: circumpolar stars. so if i keep my pointer there, [S2: oh shit ] <ROTATES CEILING> everything else moves and we all get sick. <SS LAUGH> and we go backwards in time. and that's even more fun. 
S2: make it go really really fast. 
<SS LAUGH> 
S1: okay so that's how the sky is going to move, a couple of other things that we can do in here, um, this is a representation of, the, grid, that we use to divide the sky, so these lines that run, north south what do we call those? 
S3: declination 
S1: declination, and the ones that run this way? 
SS: right ascension 
S1: okay that's a measure of right ascension. it's actually flipped when we talk about it these lines the lines of right ascension, because they measure how far, east or west we are, uh when we look up here, this part we've got numbers that have degrees so here is three-sixty, uh we're at zero, fifteen thirty forty-five. so what we find is that, if we divide, the number of degrees in an orbit so three hundred and sixty degrees, we divide that by twenty-four hours in a day, we find that there are fifteen, degree zones and that represents one hour of movement. so in twenty-four hours we'll have seen all of these stars pass this point, and we'll be back to where we started. so this line here is representing the celestial equator, it's actually a bit lower than it ought to be but, assume that that represents the celestial equator, what then does this dashed line here represent with the months written? 
SS: the ecliptic 
S1: the ecliptic. so they're not lined up, and, another thing to look at, no not that, there we go. uh, this line is running across the meridian so if we start at the base here we've got zero ten twenty, degrees all the way up to ninety degrees being at the zenith, Polaris, what number is Polaris associated with? 
S2: forty-two 
S1: forty-two. and forty-two is what... forty-two degrees of... altitude. [S2: oh ] so altitude is the number of degrees from the horizon, to a star. so this star here would be at what altitude to us? 
S2: twenty-six 
S1: yeah about twenty-six, and this one would be at, 
S4: (be at) eighty 
S1: eighty degrees of altitude. so altitude is determined by the observer. just like circumpolar stars, a star can't say oh i'm circumpolar, all the time, because circumpolarity depends on the observer. to somebody at the North Pole, there are gonna be a lot of circumpolar stars. and somebody at the equator isn't going to see many at all. or won't see any. so circumpolarity and altitude and things like that are defined by where you are, observing from. so, um, what we would find if we went outside tonight, there are_ i know this is a stellar course, so we're looking mostly at stars, but there are a few planets that are really really bright right now, so you ought to be able to find those. if we went out, and it's, six or seven P-M so just after it's getting dark, if we look over here to the southwestern part of the sky, about here, there will be a very, bright object, that's larger than any star that you'll see in the sky, any guesses on what that would be? 
S4: Jupiter 
S1: nope not Jupiter [S4: oh ] good guess 
S2: Saturn? 
S1: not Saturn, good guess 
S3: Venus?
S1: Venus. yeah it's gonna be Venus. so that'll be over here, and the other two that were mentioned Saturn, and Jupiter will be over here. [S2: oh ] so, Jupiter is, half way in size between Saturn and Venus and that's very bright, and Saturn is a little tiny dot but it's got a very intense brightness to it, and what you'll notice about planets besides the fact that they're going to be much brighter, than any of the stars, is that the planets don't appear to twinkle, so if you stare at them they'll have a constant brightness, and most stars will seem to have some change, in their apparent brightness when you look at them. now i'm going to move the sky forward just a little bit, mkay this is what the sky would look like if you went outside at say eight thirty tonight. and, Venus will be, lower that'll be way down here, closer to your horizon, and Jupiter and Saturn will be overhead. and if you look right here, we see it looks like somebody made a mistake. because it's all fuzzy, and dim. this represents the Pleiades, and the Pleiades are a star cluster. so if i took out a pair of binoculars tonight, and looked at the Pleiades, i would be able to see more than a hundred stars all grouped together, there. and the Pleiades tonight and Jupiter and Saturn, will be forming a triangle. so if you can find one you can find the others. the Pleiades if you stare directly at them they'll disappear because they're rather faint 
S2: yeah i noticed [S4: yeah ] that they 
S1: so if you look here like if you look just a little bit aways from it so that they're slightly out of the corner of your eye you'll be able to see them. it's because our eye doesn't have enough receptors, uh if you look directly at something, uh it loses its sensitivity. [S2: huh ] so you wanna look slightly away from those. um let me turn these lights up just a little but more, to make a point. when we look in the sky in the evening, we'll see a big arch, of stars here, and these are all pretty bright, and right here we can see Orion's belt, and that's very recognizable the trick to remember is that, in here everything looks very close together, but Orion's belt when you look at it, in real life, is going to look, much bigger it's going to take up a huge part of the sky. so, you gotta look for something a little bit bigger, but you'll be able to see this arch of stars, and Orion. and what i'm going to do is just briefly run through, the stars that are in this part of the sky. so that when you go outside tonight you'll be able to already, identify certain things if you're sitting in the south and want to move like over where you can see better, that might be, wise. yeah and you'll be able to see better, from here. can you see okay there? okay um, let's start with Orion, does anybody know what Orion's occupation is?
SU-F: hunter 
S1: hunter. kay so he's a hunter so he's got a couple of weapons with him, but what we see he's wearing a belt, and, these four points, here, form a rectangle and we can imagine that they are being, cinched by this belt so he's wearing a tunic, cinched by a belt. dangling from his belt, is a scabbard, and actually, they- it looks like there are three stars that make up the sword here. the middle one is the Orion Nebula. so, uh that's another thing if you've got a telescope it's a lot of fun to look at, and in this arm, you go out to his elbow here and out to his hand. uh, this is a club. so he's carrying a club. and, in this hand here we see four stars that are kind of curved. that's his shield. so in his right arm he's got a club, in his left arm he has a shield. and, there are two stars here that are bright enough that we, should learn what they are. this star up here is called Betelgeuse. and uh, anybody heard of that name before? 
S2: yeah 
SS: yeah 
S1: yeah. the Disney cartoon or Disney movie was named after that star. this star is very red, so, it tells you right there that, this star is relatively cool. and this star down here_ oh i didn't even tell you what this_ this is his right shoulder, or his right armpit, you know he's holding the club up so, that's Betelgeuse and then down on his left side, this is his left leg or his left knee or his left foot, depending on who you talk to, and that is Rigel. so we've got Betelgeuse and Rigel, anybody know what Orion is hunting?
S2: a bear? 
S1: kay not hunting a bear [S2: dang ] no good good guess uh, 
S2: cuz of Ursa that's why 
S4: a bull? 
S1: Ursa the bears are both in the north Ursa Minor is here [S2: dang ] Ursa Major is here [S2: dang ] other guesses? it is an animal 
S3: a bull? 
S4: Taurus? 
S1: Taurus. Taurus is a bull. and that is who he's fighting. what we're going to do is, the belt is here, we'll go to the right, and we get to this star, this is Aldebaran, and Aldebaran is the eye of Taurus. Taurus is a little bit unfortunate, uh in the way he's drawn. but he's got two very distinguishing features and those are his horns. and, if we start at Aldebaran, and we move out here, that's one horn, we move out here, that's the other horn. now what we notice, okay. height of horn, height of Orion. <SU-M LAUGH> <LAUGH> no wonder Orion was a little bit scared. so, Taurus here now the rest of his body is really impressive. this is his head. and his head is actually made up of the stars in another cluster called the, Hyades. so this is the Hyades that's the Pleiades. so his head is here and his body, is here. not terribly impressive. i think this is part of his body too but, kinda hard to see a bull but he does have impressive horns, and the Pleiades is riding on his back. so is Orion hunting by himself? 
SS: no 
S1: no he has with him two companions what kind of animals are they? 
SS: dogs 
S1: dogs so he's got two hunting dogs with him, we can get to the first hunting dog by following the belt down to the left, and this star is Sirius, Sirius is the Dog Star, by nickname and Sirius other than, the moon and the planets is the brightest thing that you'll see in the sky, so tonight Sirius will be very bright, and Sirius is part of Canis Major the big dog. and this is actually drawn pretty well. up here we have the head, and if Sirius is the eye, these four stars are his ears, and these four are his mouth. so he's yapping at something, so his head is very large, then these stars form his backbone, and his tail, and his back legs are here and his front legs are there. so a big head and a little body. can we call see how that works? [SS: yeah ] does it remind you of a particular type of dog? i always i don't know the name for these but if you draw a little bowtie, on his neck, and put him on a sweatshirt, look, you've seen those right? 
S2: those are basset hounds. 
S1: no they're not basset hounds are they? 
S2: they're not? 
S1: aren't they some sort of terrier? 
S3: they're Scottish terriers. 
S1: Scottish terrier. i think it looks like a Scottish terrier. so you can make your own decisions about that. the other, dog we get to when we start_ these are Orion's shoulders, so we start up here, and if we go to the left, through Betelgeuse and keep going, we get to this star here, and it's pretty bright, and the star's name is Procyon, and cyan means blue, so it's a bluer star. Procyon part of a very complex, constellation, kay? watch out. <SOUND EFFECT> <POINTS TO CONSTELLATION> did ya catch it? this star this star, two stars. <SU-F LAUGH> whole thing. <LAUGH> so not something i'd be terribly frightened of but it must be a very vicious hunting dog. so that's the one star that's the other star. very impressive. and just for fun uh do we see the star here here here those three? [SU-F: mhm ] they're very faint, uh that area of the sky, is called Monoceros. Monoceros is a unicorn. so, that takes even more imagination. uh Monoceros actually wasn't named though until like the late sixteen hundreds. so, the Greeks named the dogs but, i think it was the Dutch who named Monoceros. a constellation by the way doesn't necessarily mean just a picture in the sky, the sky is divided into like, sixty odd, regions and each of those regions is called a constellation whether or not there're any recognizable stars in it. there are two more, constellations that we should learn before we leave. okay these, three stars here, make up Orion's head. and what is he wearing on his head? guesses, he's a hunter. 
S4: a helmet 
S1: helmet nope good guess though another guess? 
S2: an orange safety hat? <LAUGH>
S1: a safety hat that would probably be wise but he's not that advanced. 
<SS LAUGH> 
SU-F: (xx) 
S2: seriously that's what they wear. i'm not kidding 
S3: that was good. 
S1: <LAUGH> okay he's wearing a baseball cap. [SU-M: hm? ] yup uh i know baseball wasn't invented back when Orion was first around. but i know he's wearing a cap, or at least for our purposes he's wearing a cap, because if we, draw a straight line up through his head, we get to this star, and that star is called Capella. so cap -ella, Capella cap, so that'll be your way of remembering that and, that's good to know because when, these stars first get over the horizon, Capella will rise before a lot of the other things in the sky. so if you can find Orion, before the, Sirius and, Procyon a- are up above the horizon you'll be able to see Capella. Capella is part of a five sided constellation, called Auriga or Auriga, and uh he's a charioteer but w- we'll talk about him more in two weeks when we come back, so just so you know that's Capella, and then the final constellation we want to talk about before you leave, is this constellation right here. we get there, by starting at Rigel, and tracing a line through Betelgeuse, and arching. and we have two bright stars right next to each other, and they represent, the heads of, Gemini, the twins. so these are brothers up in the sky, their names are Castor and Pollux, has anybody heard those names before? [S3: mhm ] Face Off the movie? [S2: yeah ] yeah okay so you'll [S3: oh yeah ] have no trouble remembering those names, and what we actually see are two stick figures doing the wave. <SS LAUGH> a- yeah we do. <LAUGH> so this stick figure here, if we started his head, there's his body, and two legs, and his arms, and here is the second twin, his body, two legs, and his arms. so they're holding hands, <SU-M LAUGH> doing the wave. right there in the sky. two stick figures. and once again when we come down in two weeks, again, we'll talk more about, who they are. so to review quickly, what constellation is this? 
SS: Orion 
S1: Orion, and this star is, 
SS: Betelgeuse 
S1: Betelgeuse 
SS: Rigel 
S1: Rigel, and if we follow the belt to the right, this is Aldebaran and what constellation is this? 
SS: Taurus 
S1: Taurus and riding on his back? [SS: (xx) ] the Pleiades, okay? if we, look for his two companions the first one here is, what's this one? 
SS: Canis Major 
S1: Canis Major the big dog and the star is Sirius, and Canis Minor, this star is, Procyon. and what we find Procyon, is on the same side as Pollux. and Castor the other twin, is on the same side of the sky as [S2: Capella ] Capella. so, Castor and Capella are close, Pollux and Procyon are close. and once again we got to Capella by going through the head of Orion. so, questions about where those things are? the point above my head just to review is, [SS: zenith ] zenith the line north south, through the zenith [SS: meridian ] meridian, the line around the base of the dome, [SS: horizon ] horizon, the celestial equator runs here, um, questions then? okay if you don't have any questions, we'll meet meet back in the room up on the fifth floor in two weeks there's no class next week, if you have questions you can stay after or talk to me in office hours on Monday or send me an email. 
SU-F: so there's homework due next week? 
S1: homework is due in two weeks. 
SU-F: oh okay 
S1: not in one week. 
<BREAK IN RECORDING; NEW CLASS SECTION FOLLOWS> 
S1: and we'll still wait another two minutes for people to show up. i had somebody, this is my fourth semester teaching and my first semester, like the third week of lab, a person in the back was like uh, we didn't go over this in lecture. like yeah yeah we did this morning. no we didn't i i know i was there and it turned out he was in the wrong place he was supposed to be next door, so we don't want to go three or four weeks till we discover we're in the wrong place. [SU-F: oh <LAUGH> ] <SS LAUGH> so if you're not here for Hughes' session of Astro One-oh-two, this is your best time to exit <P :05> and while we're waiting, on the tables we have some celestial spheres, <ADDRESSES ENTERING STUDENT> we're just getting started, and the ones on the outside tables you can spin to make the stars rise and set and the one in the middle, has lots of names on it so if you want to find a particular favorite star that's the place to look... and no one's taking me up on my offer can i see that globe that you have there can you just slide that this way? we'll be doing, an exercise with these next week, and what we find you can pull this out of the (crate,) and set it back in so that we're at a different location on the globe, and then stars, rise and set. so in two weeks, yo- you'll now come excited because you know what we'll be talking about. you here for Astro one-oh-two? good. <SU-M LAUGH> just wanna make sure. <P :08> kay. i'll go ahead and pass out a copy of the course syllabus and give you time to read through that before we talk about it. you here for Astro one-oh-two? okay. <P :08> for those of you who have come in since the explanation was given we won't always have people taping our class, they're just wanting to, get a sample of different types of classes to record so don't be intimidated by it. <P :05> everybo- body's avoiding looking in that direction and they don't record you that way. <LAUGH> okay. <P :05> have we all had a chance to read through this then? kay. my approach to this course having taught it for four semesters, is to make the discussion section as much of a lab as possible, so, we'll do our best to correspond with what's going on in lecture but that won't always work because sometimes there are, lab exercises that are just so important we can't skip them, even if they're about a lecture that happened two weeks ago. so every week i'll tell you what chapter we're, doing a lab on or what chapter we'll be talking about, and we'll try to stick to the schedule for the lecture as much as possible, i've got on my website a list of the tentative schedule for what we'll be doing, and what chapter you should have read before discussion. so our approach will be that every week i'll give you a little packet that has a mini lab and we'll spend about half the time, completing a lab exercise in groups and then half the time talking about it, or talking about any other questions that you have about, the lecture, or about, homeworks or anything like that. if you look at the upper left hand corner i have my website written down, and you will come to know and love my website. because it will have all sorts of important information it'll have, the homeworks so if you miss a class you can print it out from the website, it'll have copies of the lab exercise so if you miss a class or lose it, you can print it out from there. and perhaps most importantly i have a long list of astronomy links. so if you want to know something about black holes i've got five sites on black holes. if you want to know about observing, photo journalism, photo astronomy, uh, telescope basics history of astronomy you name it i probably have a website that has a link or two or five. so that's a good place, if you have questions on your homework or questions, about anything in astronomy to check out, okay continuing down the list then homework is the second point, and i'll give out a homework just about every week, so by the end of the term we'll probably have nine or ten homeworks that we've done, and i'll try to keep them as non-mathematical as possible but there are times where we need math. so_ but if i ask a math question i'll always ask for an explanation as well. so we won't do math just for the sake of doing math we'll try to do math in a way that explains a concept, the only exception to that rule is this week, homework number one is a math review. so it's nothing too complicated but you need to know how to add, you need to know how to work with powers of ten, and convert units so if you got an inch and you want a centimeter how do you get from one to the other. so basic math most of you this will be a review the homework will take ten minutes and you'll be done, but if you have questions about that chapter one is a good reference i have office hours on Monday and i have email and i'm very good about answering email. so, if you're intimidated by that don't be, we just wanna make sure we all start out understanding the difference between a meter and a centimeter. one of the homeworks i'll let you drop the score on, so, either if you have a bad week and you get a low score or if you miss a week, then you can drop that assignment. the key to that then is to make sure that for the most part you get your assignments done on time, i won't accept late homeworks unless you're near death, or, <SU-F LAUGH> have a valid excuse that's of equal magnitude. so, you'll want to be here, or turn it into my mailbox early, my mailbox is in Dennison on the, eighth floor, in the same hall as the elevators so, if you need to turn something in early, uh email me and i'll tell you where to drop it off, questions about homework and how that's gonna work? no, okay, uh, third point on the syllabus planetarium quiz, part of what is fun about this course is that we get to learn all about the stars and the constellations so we'll start out for the last half of today, going down to the planetarium and seeing, what we could see if it was clear tonight, and in Ann Arbor, that's <LAUGH> not a likely event, but once in every, two or three weeks it will be clear and you'll be able to see what's out there. so you'll be able to figure out, what you can see, and by the end of the term you'll know about thirty constellations and about twenty, twenty-five stars. so i think most people enjoy that part of the course, most, um, it's something that you'll remember ten years from now, you know in five, well five months you probably not five years won't remember the mass of Jupiter, but you might very well be able to recognize where Jupiter is in the sky. or you might not remember, that Alcor and Mizar are a binary star system, but you'll remember where they are. so, we'll, those will start to sound familiar to you, and i think you'll enjoy that, grades, uh point number four your discussion grade will be thirty percent of your total grade for the course, so generally, you'll want to not waste your time here <LAUGH> thirty percent is a pretty big chunk, but generally it'll pull people's grades up. homeworks are generally easier than exams so this is a good place to bring up your grade for the course, plagiarism is one way that you can bring down your grade for this course, and plagiarism is when you write something and it's not your own ideas or your own words. so we'll do a lot of group work in here, uh starting next week we'll work on celestial spheres together in groups of two or three, you'll talk with each other you'll ask questions and that's good that's why we're here. the problem though is when you, write down word for word the same answer to a homework as somebody else, or you have the same diagram, and i can't tell if you copied it or if you, actually came up with it yourself. so to discourage, people copying from one another, um i'll give a zero to anybody who copies a homework, so if you have questions about what it means to write in your own words talk with me about it now, or this coming week, or sometime before it becomes an issue. um, so that's point five, and then the last two points are office hours and meeting times, i have office hours on Monday right after the lecture, how many people have class then... okay about half of you. so for half of you that's not a convenient time, for the other half, it's just take the elevator up to the ninth floor and visit, for those of you who can't meet during that time, just email me and i'll set up another time to meet with you. so we'll just find a half hour that you don't have class and i don't have class. so not a problem, also if you have a question that you don't really need to set up an office hour for just like, uh you had a typo on that question, or, ha- is this a good start to an answer for number three? just email, to me and i'll try to get back to you within a day. so if there are less complicated things that's an easier way to ask questions. and then meeting times, you're scheduled for_ i teach four discussions, during the week Monday, at one and two and Wednesday at one and two and you're the last one. so you're at a bit of a disadvantage in that if you miss this class you don't have any make ups to go to. but what that means is that if for some reason you can't come to a Wednesday class, if you write to me ahead of time you can come on Monday. so i really don't care which class you show up to just come to one of the four, and let me know ahead of time so we don't have forty people show up to one class. questions about, how this is going to work? no? okay let me hand out the first homework, there are three, math questions and then the fourth question, i'll ask you to look at my website, and critique it and tell me what site to get rid of. and what site to add. so, previous students have designed, the links on that site and you'll be continuing that... uh check to make sure you've got two sides, to that too <P :04> we will not be meeting next week. um, for discussion you will have lecture on Wednesday, but because there are no discussions meeting on Monday, because of Martin Luther King Day, we'll also not meet. so this homework is going to be due in two weeks. on the_ uh for those of you who are more inspired than others, i already have homework two posted to my website, that's not due for three weeks, you don't need to worry about it, but, part of, homework two will be working with a computer program that's available, in like the Fishbowl, or the other, I-T-D sites, and that'll take you about an hour, to figure out, so if per chance this Saturday evening you're sitting at home and you're really bored, and you want to work with a computer program, uh you already have the opportunity to do that but most of you i don't expect to think about it for two weeks and that's okay. so don't panic when you see the homework two, on the website when you look at it and say, <GASPS> maybe there are two homeworks due, uh, no homework one is due in two weeks. and, i think that pretty much covers everything we need for an introduction are there questions about, anything we've talked about so far...? no? okay what we're going to do then for the rest of the class is move down to the third floor to the planetarium, and talk about what we see in the sky. you can bring your stuff with you, we'll leave from there, you can leave it here if you want to and we'll just lock the door. 
{END OF TRANSCRIPT}

