Astronomy calculators

Astronomy Tool Code Legend

How to navigate this hub

Start with Workspace when you run several astronomy tools in one session.

Use Observing planning for tonight's sky window and moon conditions.

Move to Coordinates & time and Imaging & gear when you set capture details.

Workspace & integration

Use one project workspace to keep targets, shared conditions, and equipment aligned across tools.

Astronomy Workspace Pro (A15)
Manage Observability time plotter (A7) / Imaging planner (A9) / Session Planner Pro (A11) / Mosaic Planner Pro (A12) / Finder Chart Pro (A14) / Field Rotation Planner (B3) in one project and reopen each tool with the same location, date, and setup.

Observing planning

Plan darkness, moonlight impact, and target observability before observation.

Observability time plotter (A7)
Evaluate altitude, twilight, airmass, and moon constraints and extract best observing windows.
Catalog Resolver Pro (A13)
Search M/NGC/IC/C IDs and names, then hand off targets to planning tools.
Planet observation planner (A8)
Overlay planet altitude, twilight, and moon impact to extract practical best windows.
Twilight, sunrise, and sunset calculator (A5)
Get sunrise/sunset and civil/nautical/astronomical twilight with fixed thresholds.
Moon visibility (A6)
View moon age, illumination, rise/set, and daily altitude curve.
Solar position calculator (altitude/azimuth/sunrise/sunset)
Quick solar altitude/azimuth and sunrise/sunset estimation.
Tide, moon phase, sunrise & sunset calculator
Check tides, moon phase, and sunrise/sunset in one place.

Coordinates & time

Use these tools to convert time standards and sky coordinates.

Julian date (JD)
Convert local date/time to Coordinated Universal Time (UTC)-based JD, MJD, Unix time, and ISO timestamps.
Local sidereal time (LST)
Compute Greenwich Mean Sidereal Time and Local Sidereal Time (GMST/LST) from date-time and longitude, and optional Hour Angle (HA) from RA.
Altitude and Azimuth (Alt/Az) converter
Convert Right Ascension and Declination (RA/Dec) to Altitude and Azimuth (Alt/Az) at one instant and across a daily altitude curve.
Angular separation
Get angular separation and position angle (Position Angle (PA)) between two sky positions.

Imaging & gear

Plan framing, alignment, and safe exposure length in one flow.

Imaging planner (A9)
Estimate field of view, pixel scale, diffraction limit, and sampling balance from your setup.
Polar Alignment Pro (A10)
Get reticle angle and clock direction with mirror/rotation/offset calibration.
Field Rotation Planner (B3)
Compute q(t), dq/dt, and estimate rotation-limited max exposure.
Session Planner Pro (A11)
Compare multiple targets under one-night constraints and decide the observing order with score + timeline.
Mosaic Planner Pro (A12)
Generate NxM panel centers with overlap, PA rotation, and panel order for practical shooting plans.
Finder Chart Pro (A14)
Generate practical finder charts with orientation controls and Imaging planner (A9) / Mosaic Planner Pro (A12) overlays.

Learning fundamentals

Use simple formula tools to learn astronomy basics.

Distance modulus calculator — m−M = 5 log10(d/10 pc)
Learn the relation between apparent magnitude, absolute magnitude, and distance.
Kepler's third law (orbital period) calculator
Explore the relation between orbital period and semi-major axis.

Astronomy

Astronomy Session Planner.
Plan one-night observing sessions by ranking targets with shared constraints, timeline views, and CSV/JSON export.
Astronomy Workspace Pro.
Manage observing projects in one workspace, keep shared location/date/equipment settings, and open linked astronomy.
Catalog Resolver Pro Calculator.
Offline catalog resolver for M/NGC/IC/C IDs with filters, sorting, multi-select, CSV import, and CSV/JSON export.
Distance Modulus Calculator With Steps | Solve m, M, or.
Enter apparent magnitude, absolute magnitude, or distance to solve the distance modulus formula with steps.
Field Rotation Planner.
Plan parallactic angle and field rotation rate through the night, with optional exposure limit estimate.
Finder Chart Pro Calculator.
Build finder charts from Right Ascension (RA) and Declination (Dec) with grid, scale bar, orientation markers.
Imaging Planner (FOV, Pixel Scale, Resolution).
Plan imaging setup with Field of View (FOV), pixel scale, diffraction limits, and seeing-based sampling guidance.
Kepler's Third Law Calculator.
Use Kepler third law (T^2 = a^3/mu) to solve orbital period or semi-major axis.
Mosaic Planner Pro Tool.
Generate NxM mosaic panel centers from target, Field of View (FOV), overlap, and Position Angle (PA) using gnomonic.
Planet Observation Planner.
Plan planet observation windows with altitude curves, twilight overlay, moon impact, best-window extraction.
Polar Alignment Pro Calculator.
Compute pole-star reticle angle, clock position, and time-series drift for practical polar alignment in the field.

Choose the right astronomy planning path

This hub is for routing, not for generic theory. Start with the next deliverable you need tonight: resolve a target, check the timing window, rank several candidates, plan a mosaic, or print a finder chart.

Open these first

Open Catalog Resolver Pro when the first job is turning a name or catalog ID into clean coordinates.
Open Observability when the target is known and the next question is whether it clears your altitude, moon, and twilight limits.
Open Session Planner Pro when you need one ranked shortlist under one observing setup.
Open Mosaic Planner Pro when one frame is not enough and you need panel centers.
Open Finder Chart Pro when the next deliverable is a usable field chart.

Use another science hub when

Move to Physics if the next step is wave, optics, or mechanics math rather than observing workflow.
Move to Chemistry or Earth science when the next question leaves astronomy and becomes lab or environment work.

FAQ

Which astronomy page should I open first?

Start with Catalog Resolver Pro if the target identity is still fuzzy. Start with Observability if the target is fixed and you only need to know when it is usable.

When does Session Planner matter more than Observability?

Use Observability for one target and one timing window. Use Session Planner when you need to compare several resolved targets under the same sky and equipment limits.

When should I jump to Mosaic Planner or Finder Chart Pro?

Move to Mosaic Planner when the framing needs panels. Move to Finder Chart Pro when the next output must be a readable chart for the field or for sharing.

What does Astronomy Workspace add?

Astronomy Workspace keeps the same location, date, and setup across several astronomy pages so you can compare the next steps without rebuilding the session from scratch.

Next steps

Catalog Resolver Pro
Resolve a target name or catalog entry before sending it to the rest of the planning stack.
Observability
Check whether a resolved target actually fits tonight's altitude, moon, and twilight constraints.
Session Planner Pro
Rank multiple targets in one session when timing and setup are already shared.
Astronomy Workspace Pro
Keep one project workspace when you need to move between astronomy pages without losing context.