Learning Objectives
- Use coordinate systems and planetarium software to plan a reproducible observing session.
- Make measurements or classifications with explicit uncertainty.
- Separate direct evidence from model-dependent interpretation.
Preparation
- Read OpenStax Astronomy 2e sections 2.1-2.2 on celestial coordinates and apparent sky motion.
- Install or open Stellarium Web and set the observing location assigned by the instructor.
Materials and Data
- Stellarium Web or desktop
- Instructor-provided target list of 5 objects
- Observing plan worksheet
Apparatus and Setup
- Set Stellarium to the assigned observing site and disable atmospheric refraction only if instructed.
- Load the five-object target list and verify each object has RA/Dec visible in the information panel.
- Create a two-hour observing window in 30-minute increments.
Procedure
- Set the observing location and date/time to the assigned lab window.
- For each target, record RA, Dec, altitude, azimuth, rise/set or visibility notes, and whether the target is above 25 degrees altitude during the lab window.
- Select two feasible targets and one infeasible target. For each, explain the evidence from coordinates and local sky position.
- Advance time in 30-minute increments across a two-hour observing window and track altitude changes for one selected target.
- Create a final observing plan with target order, estimated observing times, finder directions, and backup target.
Measurement Record
Use this structure or an equivalent table in your lab notebook.
| target | RA | Dec | time | altitude | azimuth | observable? | reason |
|---|---|---|---|---|---|---|---|
Analysis and Uncertainty
- Explain why RA/Dec are reusable but altitude/azimuth are local and time dependent.
- Use the altitude trend to decide the best observing order.
- Identify one uncertainty or practical constraint such as horizon obstruction, twilight, Moon phase, weather, or instrument field of view.
Deliverables
- Completed target table
- Two-paragraph observing plan
- Screenshot or exported chart with labels and source noted
Assessment Criteria
- Correct coordinate interpretation
- Feasible target selection
- Evidence-based observing sequence
- Clear chart labels and source acknowledgement
References, Software, and Data Provenance
- OpenStax Astronomy 2e, sections 2.1-2.2
- Stellarium Web: https://stellarium-web.org/
Any additional dataset, image, or software source used by an instructor should be added to ../reference-log.md with source, access date, license or usage note, and processing steps.