ASTRONOMY 101 CLASS NEWS AND INFORMATION

** FINAL EXAM on FRIDAY May 8.
Here is the final version of the Final Exam Study Guide.

Additional Astronomy Help Room hours
Thu, May 7: 6 pm - 7 pm
Fri, May 8: 10 am - 1 pm


As we take our finals, the stress levels can be high, especially this semester. If you, or a friend, are feeling way over-stressed, maybe talking with a counselor can help: SDSU Counseling Services

Some of you may be interested in the following course, taught in the spring: Astr 310: Astrobiology and the Search for Extraterrestrial Life (Note: the dates and times are no longer correct on this poster). This course builds upon what you've learned in Astronomy 101 and satisfies upper division GE science requirements. For details about this course, see the course web page and look under "syllabus": Astronomy 310.


Apr 30:
- Here is a revised version of the final exam information. Please pay close attention to the instructions for the exam.
If you cannot take the final exam at the usual time, you must let me know by Monday morning. We will then schedule a make-up exam that will be mostly essay questions and possibly an oral part (done live via Zoom).

Apr 25:
- Here is a PRELIMINARY final exam study guide. Much of is from a previous semester, but it will be very similar to the final version that will be posted later. You can use it to get a head start. Check back for a revised version.
- Lecture notes on Cosmology

Apr 22:
- Notes on Galaxies and the Milky Way
- It is best if you read all parts of all chapters, as this provides continuity of the material. But if you are pressed for time, here are the sections of the textbook that you can give low priority to:
Ch 8 section on helioseismology (p 133)
Ch 9.2 magnitudes (p 153)
Ch 11.1, 11.6
Ch 12.2 - 12.3 relativity and gravity
Ch 13.2, 13.4; Ch 14.8; and Ch 15.6.

Apr 19:
- Exam #3 class average was 41.8/50 (median=45) which is very respectable. Nice work!
The numerical score-to-grade conversion (i.e. the curve) for Exam # 3 is:
A=44-50; B=38-43; C=32-39; D=26-31
- For reference, as of today a total of 220 points have been assigned in MasteringAstronomy. The class average is 189.6 points (86%). If you don't have around 180 points or higher, then your score is below the class average and hence into the "C" grade range. Please try to get as many points as possible as we do the last 3 homework sets. These are large homework sets, so there's lots of possibility to gain a lot of points.
- Reminder: Free on-line tutoring at the Astronomy Help Room.

Apr 18:
- Notes on The Sun.
- Notes on Stars & Stellar Astronomy
- Notes on Binary Stars. Unlike the other notes, these are the actual PowerPoint slides.
- I recommend you review the spectroscopy and blackbody concepts in Chapter 2 while studying the Sun and the Stars.
- As we push into the final part of the semester, the pace will noticeably pick up. Please keep up with the reading assignments. We will cover the entire rest of the book, though not everything is of equal importance. The following sections are lower priority:
Ch 8 section on helioseismology (p 133)
Ch 9.2 magnitudes (p 153)
- If you have any trouble with the material in the textbook or the homework, please make use of the Astronomy Help Room or office hours.




Apr 16 :
- FINAL version of the Exam #3 studyguide. There have been no changes since the version posted on April 10th.

Apr 10:
- DRAFT version of the Exam #3 studyguide. Be sure to check back for an updated version in a few days.

Apr 6:
Welcome back after spring break!
+ To encourage you to ask questions during our Zoom class meetings, I will "reward" you with extra credit points. If you ask a good question in class and would like to earn extra credit, please follow up with an email that gives me your name, the question, and the answer. This can be very brief - one or two sentences is fine. For now, you can earn one point per class (a point is worth the same as an exam question).
+ Apologies for the error in the due date for the MasteringAstronomy HW #6. It has been reset to Wednesday at 1pm. The next homework, #7, is due the following Wednesday (Apr 15) at 1pm.
+ Exam #3 is next Friday (April 17). It will be via Blackboard and start at the usual class time (1 pm). It will be a timed exam and end at 2 pm. It will be an open-book exam. Details and study guide to come later. If you can't make it to class next Friday, please let me know well in advance and provide alternate times to take the exam.

Mar 25:
Our on-line live Zoom lectures continue. Thanks for coming to class!
If you have any questions, please do not hesitate to write or schedule a Zoom meeting.
Recordings of the Zoom lectures are generally not available, but if you can't make it to class, let me know in advance and I will try to send you a link to the recording. Not all lectures are recorded though.

Mar 18 :
- If you would like to talks with me during office hours, please send me an email in advance. Due to internet bandwidth limitations (for me and for others), it does not make any sense to have a live Zoom session going during office hours if nobody is interested at that time.
- How fast is 75 km/s? It doesn't sound that fast, does it? But converting to miles per hour, we get 150,000-160,000 mph! That is really, really fast!! Compare this to a "speeding bullet": a fast bullet (rifle) goes "only" about 2000 mph, 75 times slower than a meteor! The Space Shuttle goes an amazing 17,500 mph, but this is almost 9x slower than a fast meteorite. To be clear, meteoroids and NEO asteroid and comets can be going much slower than 75 km/s with respect to the Earth, but their top speed can be as high as 75 km/s! That's why they carry such a punch - their velocity gives them huge energy.
- Here are some links about the discovery of gravitational waves: Gravitational Waves Detected, Confirming Einstein's Theory from the NY Times.
Gravitational waves, Einstein's ripple in spacetime, spotted for first time from Science.
Gravitational waves: a three-minute guide from Nature.

Mar 17 :
- Here again is the Exam 2 score-to-grade curve. It is very similar to the curve for Exam 1, and it is also out of 50 points:
A = 42 and above (>84%)
B = 35-41 (70-82%)
C = 28-34 (56-38%)
D = 22-26 (44-52%)
The average grade was 35.2 (70.4%); median grade 38.
- Note: One student lost 1 or more points on their exam because they did not fill out their Red ID or other info on the scantron forms correctly. Please try to be more careful.




Mar 9:
- Here is the revised Exam #2 studyguide. It is very nearly the same as the earlier draft.
- EXAM #2 on Friday March 13 You will need the big pink "ParSCORE Enrollment" form for the multiple choice exam. Be sure to fill out your ParSCORE form correctly! If you have mistakes, you will lose points on your exam (1 point per error). Common errors include:
. + not making the pencil marks dark enough
. + putting an extra zero in front of your Red ID
. + putting a blank in front of your Red ID (leave the last column empty)
. + filling in wrong digits on your Red ID
. + filling in two answers bubbles because of sloppiness
. + not erasing an answer fully
This is EXAM 002, TEST FORM A.


Mar 6:
Emphasis will be on Chapters 2, but also Chapter 3 and 4. Be sure to be able to answer questions using Wien's Law, the Doppler effect, Kepler's 3rd Law, luminosity, etc.
+ DRAFT Studyguide for Exam #2 (this is a preliminary version and will be updated).

Mar 4:
+ Reminder: Exam #2 next Friday.
+ Lecture notes Astr101_08.pdf Solar System, Part II. The Solar System topics will not be on Exam #2.

Mar 2:
- Lecture notes Astr101_07.pdf Solar System, Part I.
- Please examine and explore NASA's Solar System Exploration website.

Feb 26:
- If you have any trouble with the math or formulae covered in class, please ask for assistance. Make use of the free tutoring in the Astronomy Help Room.
- About the next generation of telescopes: Here's an old San Diego Union Tribune news story from Feb 2009: Time To Zoom In On The Universe. Most parts are good, and the Kepler telescope turned out to be increadibly successful. But the expected dates for the construction of the next generation telescopes is way, waaaay off.

Feb 21:
- Lecture notes Astr101_06.pdf on Telescopes.
- The Fleet Science Center offers excellent planetarium shows. The next one-per-month astronomer-led planetarium show is on the evening of Wednesday March 4th. There are also free telescope viewing (weather permitting) in Balboa Park on the first Wed of every month (also the same night as the planetarium show). Click on the link to get more information and prices.

Feb 19:
- Reminder: You may earn an extra point or two if you report any major errors in the textbook, notes, or class web pages. Speling misteaks do'nt kount, (sic)
- Astronomy is an observational science; we cannot do experiments in a lab the same way you can in most other sciences. Professional astronomers (and students too!) are at the mercy of the weather. Sometimes you have to wait all year (or more) to get a chance to use a big telescope to do your research project, and if the weather is bad on those nights, well, try again next year! So we need to have lots of contingencies ("plan B" projects).
+ Suggestion: please watch the video "Infrared: More Than Your Eyes Can See" from the Spitzer Space Telescope team. The link is on the main class webpage. The video is very helpful in understanding several concepts in this course, especially infrared light. If you have any questions, please ask.

Feb 17:
- Exam 1 Curve (out of 50 points):
A = 42 and above (>84%)
B = 36-41 (72-82%)
C = 28-35 (56-70%)
D = 22-27 (44-54%)
The average grade was 38.8 (77.6%); median grade 44.
Two student did not fill out their scantron forms correctly! Please be more careful. Common errors include:
. + error in Red ID (missing or extra digits; wrong columns)
. + filling in two answers bubbles (bad erasing or sloppiness)
. + not filling in the "TEST FORM A" bubble
. + not filling in "EXAM # 001"
Please don't throw away points! Just a few points can make a difference in your grade.
- On the MasteringAstronomy homework, 72 points have been assigned so far. The class average for HW #3 was an excellent 96%. Keep up the good work!

Feb 12:
+ Final updated version of the Study Guide for Exam #1. The only change from the previous version posted Sunday is the addition of one practice question on the phases of the Moon.
- Please fill out your ParScore scantron form carefully. In the past, some students have lost up to 8 points!! That is more than a full letter grade - all because they didn't fill our their Red ID and other info correctly. Please don't let it happen to you. Fill out this info before coming to class. This is a homework assignment.

Feb 10:
+ Updated hints for Exam #1.
The exam will not cover anything to do with Newton or Newton's laws.
- The class average for the MasteringAstronomy homework assignment #2 was 21.2/20 points - lots of extra credit being earned - even better than last time!
- The above score is even more impressive when you consider the "bug" in the MasteringAstronomy software that required you to hyphenate "light-year" as an answer. To compensate for this frustrating bug, I am awarding everyone in the class an extra point on this homework assignment. I cannot make this show up in MasteringAstronomy, but it is recorded in the spreadsheet I use to compute the course grades.

Feb 6:
- I am unable to have office hours on Monday Feb 10th. To help compensate, I can have extra office hours during the rest of the week (by appointment).
- The due date for HW #3 has been changed to Thursday midnight.
- EXAM #1 on Friday Feb 14 You will need the big pink "ParSCORE Enrollment" form for the multiple choice exam. Be sure to fill out your ParSCORE form correctly! If you have mistakes, you will lose points on your exam (1 point per error). Common errors include:
. + putting an extra zero in front of your Red ID
. + putting a blank in front of your Red ID (leave the last column empty)
. + filling in wrong digits on your Red ID.
. + filling in two answers bubbles because of sloppiness
. + not erasing an answer fully
- For homework, fill out your name, Red ID, etc. on a ParSCORE Enrollment form.
- Here is an old, previous study guide for the exam. Use it to help you focus, but realize it is not the final version for this semester. The final version will be posted this weekend. Preliminary hints for Exam #1.

Feb 5:
- The class average for the MasteringAstronomy homework assignment #1 was 87.4% or 20.3/23 points (omitting those who did not do the assignment and earned a zero score). Good job! Keep up the good work!
- Lecture notes Astr101_05.pdf on the Nature of Light and Matter.
- I will post a *draft* study guide for Exam #1 by the end of the week. The first exam will cover all the class notes, and all the homework assignments. - We will use the big pink "ParSCORE Enrollment" form for all exams.
- To help you learn the material, try answering all the multiple choice questions at the end of each chapter. If you have any trouble, come to the Astronomy Help Room or office hours.

Feb 2:
- Happy Cross-Quarter Day!
- Try to attend a planetarium show.
- Reminder: If you are having any trouble with the course, please ask or go to the Astronomy Help Room. Let us help you!
- I will not have office hours on Monday Feb 3rd.

Jan 31:
- Lecture notes Astr101_04.pdf
- Reminder about the "bugs" in the MasteringAstronomy website: sometimes an answer will require you to enter a period a the end of a sentence, or hyphenate terms such as "light-years". If you find more errors, please let me know. The first students to do so *might* earn some extra credit. But even if you don't get extra credit, you can get the point for the correct answer.
- A note from the textbook publisher: In high school, students spend ~35 hours a week in school and only a few hours a week studying on their own. In college, students are in class for about 15 hr/week and complete their education on their own time. They are much more responsible for their own learning. College students should spend 2 additional hours per unit per week for every hour that they spend in class. For 15 units, that means an additional 30 hours a week outside of class. This is what is recommended, and this is what many professors are expecting. If you do this, you are very much more likely to earn excellent grades.

Jan 28:
- Lecture notes Astr101_03.pdf on the Greek astronomers and Copernicus.
- Read Appendix C for a refresher on basic math skills. If you have any trouble at all with any of this, please see me and/or the Astronomy Help Room TAs for assistance. Please do this now, at the start of the semester, not just before an exam when it may be too rushed.

Jan 27:
- Please try to attend a planetarium show next week. When you sign in, please state that you are in Dr. Welsh's Astr 101 section.
- SDSU Astronomers Discover Two New Tatooine Planets

Jan 24:
Here are some hints for observing the sky.
- When looking at the sky, here's an easy way to determine which direction is approximately south (if you don't have a compass or smart phone with a compass app): Notice where the Sun sets. Then extend your right arm out from your side toward the direction where the Sun set. You'll then be facing southward, roughly. Your right side will be oriented towards the west, and your left side towards the east; behind you will be north. (Technically you'll be facing a bit more southeast if you do this in the winter, because the sunset is not due west, it is a bit toward the southwest.)
- When trying to observe Orion, here's a check to be sure you're looking at the right stars: Using Orion's belt as a guide, follow the 3 stars toward the southeast (to the left if you're facing south) to the very bright star Sirius. Sirius (the "dog star" in the constellation Canis Major) is the brightest star in the sky. Orion should be close to the meridian around 9 pm.
- If you are having trouble finding the constellations and/or stars, then maybe this guide from Sky & Telescope magazine will help. It is a 10-page guide to getting started in observing the heavens, in .pdf format. It includes a Moon map and star charts for different times of the year, as seen from the Northern hemisphere. Sky & Telescope: Getting Started [pdf format] (Copyright 2003 Sky Publishing Corp).
See the web page Getting Started in Astronomy for more info. - When using star charts, remember that they are only valid for certain dates and times. A January chart is often best for observing in January - but that may only true if the time is between 9 pm and midnight. For earlier in the evening, charts for December or November might be better. For very late in the evening (early morning), charts for February or March charts are better.
- Lecture notes Astr101_02.pdf.
- Remember, the lecture notes expire after the topic is covered in class, so download the notes and bring them to class.

Jan 22:
- Here are notes on the metric (SI) system and some reference temperatures, lengths, and velocities (in .pdf format).
- Lecture notes Astr101_01.pdf.
+ 2020 Spring Planetarium Shows:

Because there is a strict limit to the number of students that can fit into the planetarium, you must sign up for the show ahead of time and reserve a seat. A role call may be taken to confirm attendance. The planetarium is in the Physics and Astronomy building (see map below), in room PA-209 (second floor, at the rounded corner at the south-west end of the building; entrance near the windows). Please do NOT attempt to enter the planetarium if the door is closed! It would ruin the show and everyone's night vision adaptation. Do not be late.




SAFETY ISSUES
The CSU takes the issue of classroom and campus safety very seriously. To find information about San Diego State University's emergency preparedness plan and opportunities for training on many aspects of the classroom/workplace see: SDSU Emergency Preparedness.
SDSU Campus Safety

• Be aware of your surroundings.
• If you see something suspicious, report it!
• If you have an emergency, call 911 from any phone on campus.
• Other incidents, call Campus Dispatch at 4-1911.
• In the evening, call Campus Escort if you would like an escort to your vehicle or campus dorm.