Night Sky Map & Star Chart
A zenith-centred chart with a time slider and custom poster exports.
Try before you buy.
- Free preview: the rules, dates and checks that apply to your figures, with every computed amount hidden.
- Locked until you unlock it: download and copy.
- Unlock: Pro pass, ₹179 for 30 days or ₹79 for 1 week, a one-time payment that never renews. Unlock: Pro pass, $5.99 for 30 days or $2.99 for 1 week, a one-time payment that never renews.
Ways to unlock shows how to get the full result.
Printing this result is locked in the free preview.
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The list offers a keyboard alternative to tapping chart points.
Conventions and model limits
Locked in the free preview. Opens the ways to unlock this result.
Locked in the free preview. Batch runs unlock with a pass.
Locked in the free preview. Query results unlock with a pass.
About the Night Sky Map & Star Chart
Draw the sky above your entered horizon using 5,044 catalogue stars, canonical constellation figures, the seven planets, Moon and Sun. The altitude-azimuth grid centres on the zenith, with north at the top and east on the left as you look upward. A time slider explores the surrounding day.
The free preview marks the calculated chart and masks detailed quantities. A Pro pass opens object inspection, complete results and clean SVG or PNG exports, plus a genuine vector PDF poster with a custom caption, two styles and selectable paper formats.
How to use it
- Enter your location and UTC instant; verify the separate output time zone.
- Choose the faintest catalogue magnitude, constellation figures and time-slider offset, then draw the map.
- With a pass, inspect a star or Solar System body with the object list or by tapping its chart point.
- Set a custom caption, clean export style, pixel size and PDF paper format; calculate again after edits.
- A pass unlocks clean PNG and SVG maps, a vector PDF poster, and copied or downloaded text details.
Examples
An object at altitude 0°, azimuth 90°
It lies at the left (east) side of the horizon circle.
Your chosen place, historic UTC instant and caption
An approximate star-position chart with a custom vector poster; no exact historic sky observation is implied.
Coordinates and catalogue
Mean J2000 equatorial positions are rotated into the current horizon. Proper motion and atmospheric extinction are omitted. Names and designations are used where the data supplies them; unmatched stars retain a HIP identifier. Serpens uses separate figure records for its two regions.
Sources and data rights
Star and canonical constellation data are adapted from d3-celestial data files under its BSD licence; the project identifies its stellar catalogue sources. Calculation library documentation describes the ephemeris, coordinate conventions and its stated validation scope. Model predictions remain distinct from observations. Constellation figures are conventional drawings, not official boundary polygons.
Limitations
- Long-past and far-future star positions omit proper motion. This is a chart and scale model, not precision astrometry or navigation.
- Only above-horizon points are plotted. Daylight charts still draw catalogue stars; actual visibility depends on the sky and observer.
- Deep-sky objects and official boundary polygons are absent. Constellation segments with a below-horizon endpoint are omitted.
- The Moon point locates its centre and does not depict the phase. PNG and arbitrary-caption font rendering depend on the browser; unsupported PDF glyphs can require a different caption or SVG export.
Privacy
On this device; its files download once
Calculation code and reference assets load from MySmartCoPilot on first use. Your inputs, coordinates and custom text stay on this device. Use my location invokes your browser only when pressed; no coordinates are transmitted.
Frequently asked questions
What do I get without a pass?
Without a pass, Night Sky Map & Star Chart shows the rules, dates and checks that apply to your figures, with every computed amount hidden. Until you unlock it, the result can’t be downloaded or copied. A Pro, Premium or Ultimate pass, a one-time payment that never renews, unlocks the full result. The pricing page lists the passes and their prices.
Why is east on the left?
The chart represents looking upward, with north at the top. This reverses east and west compared with a ground map viewed from above.
Can I make a large print?
A Pro pass unlocks vector PDF pages in A4, A3, A2 or Letter, plus self-contained SVG. Points, grid lines and labels remain vector objects rather than a screenshot.
Does every catalogue star have a common name?
No. Available names or designations are used; records without one use a HIP identifier. The accessible list always retains the identity.