How to use PlanAstro

A location-aware astrophotography planner that takes the guesswork out of your nightly imaging plans.

1. Getting started and your account

PlanAstro opens on one screen: a live all-sky chart with small buttons around it. The icons on the left open panels over the chart, the clock sits bottom-right, and Search sits on the right.

• Create an account or sign in at the start, or later from Menu → My Profile. Signing in takes you straight to the sky chart. Your account keeps your Favorites private to you and available on every device you sign in on. You can sign out again from Menu → Sign out at any time.
• Set your location — Menu → Location settings. Use your device location or type latitude and longitude. Everything else — darkness times, altitudes, pointing windows, weather — depends on it. Your signed-in location is restored before planning starts. A recent forecast saved for those coordinates appears immediately, then refreshes quietly in the background.
• Time control opens as a small panel attached to the clock in the bottom-right corner, and steps forwards and backwards through the night or jumps back to Now. Every chart, altitude graph and pointing window follows the time you pick.
• Display controls what appears on the chart: sky survey imagery, labels, constellation art, lines and boundaries, degree-labeled grids, the horizon, and the chart symbol key.
• The Menu stays open when you close a panel you opened from it, so you can move between My Profile, Location settings, My Astro Rig, My Archive, ISS Tracker and About Us; close it with the X or by tapping the sky.
• Panels that float over the chart are gently see-through, so you keep a sense of the sky behind them.
• On phones, PlanAstro reads the live screen size and safe margins. Search, Browse, Favorites, Display, object-card actions and the atlas resize and wrap so controls are not cut off, including on narrow and landscape screens.

2. The sky chart

Drag to pan and pinch to zoom across the whole chart. Below-horizon sky is less transparent but targets are still selectable. The compass steers the chart with your phone, and the center control returns to the default 88.1° view.

Pan-STARRS1 and SkyMapper provide the default sharp optical sky. WHAM H-Alpha, NASA 2MASS J, NASA 2MASS K and NASA WISE show their native wide-field imagery, then automatically change to sharp Pan-STARRS1 or SkyMapper detail below 15° instead of enlarging softer source pixels. SDSS remains sharp where it has coverage and uses the same optical pair outside it.

Sky Atlas chart. The chart now shows the real photographic sky from Aladin Lite behind your labels, constellation art, grids, horizon and planets, all lined up with your location and time. Use Stack at the top right to change surveys, overlays and catalogs; its lists open below Conditions and scroll. Locate keeps a pulsing marker on the target until you move on. Turn on Classic chart in Display to use the drawn chart instead.

The round launchers between Menu and Display open the main tools from the left: 🔭 My Astro Rig, 🗂️ My Archive, 🛰️ ISS Tracker and 🔆 Display. Menu holds your profile, Location, this guide, Contact Support and About PlanAstro.

3. Finding targets

Open Search and type a name, catalog number or common name — M31, NGC 7000, Sh2-155, "Veil". PlanAstro charts 81,411 objects — 20,299 unique deep-sky targets from 17 catalogs plus 61,112 catalog stars. Search covers every deep-sky target and its aliases (22,860 names and designations), and results narrow as you type.

• Browse opens a visual directory. Pick one of the colored object-type tiles or a row under Core, Extended or Advanced catalogs; the matching target list opens in the same panel. Use the back arrow to return to the directory.
• Search accepts catalog numbers and common names and keeps recent searches nearby. Search sorting and Tonight's best for my rig are free for every user. Once a target list is open, they and the object-type key remain available.
• The object type key lives inside Search Filters and in the Display panel. Tap any type — emission nebula, reflection nebula, planetary nebula, supernova remnant, galaxy, open cluster, globular cluster — to show only that type. Both keys stay in sync.
• Target finder suggests what is well placed right now for your location, gear and sky.
• Favorites and Imaged are full card lists. Favorites is a saved list rather than a search surface: no search box or type key, just Tonight's best for my rig and Sort. Starring from a card shows up there straight away, even for objects in catalogs that were not loaded yet. Signed-in lists are private and synchronized with your account.

4. Object cards

Tap any object to open its card. Expanded, a card shows:

• Coordinates, type, size, magnitude and surface brightness.
• An altitude timeline for the night, with your usable pointing window shaded and the meridian crossing marked. It spans the width of the card content.
• Yellow Tonight and Point your rig lines that spell out the usable window in plain words, wrapping onto as many lines as they need.
• One row of actions: 📝 Plan It, 🎯 Locate (center the chart on it), 📌 Target (add it to tonight's list), 💫 favorite and ✓ imaged. On larger screens the labels read in full.
• Sky Atlas and SIMBAD-VizieR sit together above the picture. The Sky Atlas (Aladin Lite) and the SIMBAD-VizieR reference replace that picture inside the card, rather than opening over Search.
• Buttons to add the object to Favorites or mark it Imaged.
• A Position approximate note if the catalog position could not be confirmed against SIMBAD.
• Plan It in the card's top action row replaces the card content with a visual imaging dashboard for your active rig; Back returns to the same target. It includes a color-coded quality score (Good 80–100, Workable 40–79, Poor 0–39), best window and altitude timeline, image-scale sampling bar, exposure recipe, rig gauges for coverage and focal length, and staged framing and processing checklists. Tap the small i beside any gauge to see what its colors mean. Plan It is read-only.
• A Moon warning appears between Point your rig and the altitude chart when a bright Moon will wash out a broadband target.

5. Planets and the Moon

Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune are drawn on the chart along with the Moon, each with its own symbol and label. Tap one to open a card just like a deep sky object: current position, altitude through the night, transit time and a picture of the body. The Moon also drives the moon-interference advice in Conditions, so you can see at a glance whether it will sit in your way. The Sun is used for twilight and darkness calculations but is not a chart target.

6. Tonight's plan

The planning view sequences your chosen targets across the night: when each one clears your minimum altitude, when it transits, and when it drops or the sky brightens. Use it to decide the order to shoot in and how much time each target really has.

• Targets you set from a card are collected here in time order, with their shaded windows side by side.
• Horizon obstructions, the meridian flip and your lowest usable altitude are all taken into account, so the plan matches what your mount can actually do.
• Change the time with the clock and the whole plan re-reads for that moment.

7. My Astro Rig

🔭 My Astro Rig on the chart — free for every user. Save your real equipment once and PlanAstro tailors framing and pointing windows to it. You can keep up to six rigs and switch between them. To add a rig, tap an empty tab (for example Rig 3), fill it in and tap Save. Save always updates the tab you are on; the red Delete button clears that tab after you confirm. Opening the app never removes a saved rig. Saved rigs sync across all your signed-in devices, free or Premium.

• Telescope — tap the field and a searchable list drops down with popular models; typing narrows it. Selecting one fills aperture, focal length and f-ratio, all still editable. Not listed? Enter your own and submit it for the community list.
• Camera — sensor size and pixel size drive field of view and arcsec/pixel.
• Sensor format — Full frame, APS-C and Micro 4/3 fill in the sensor width × height, which you can edit to match your exact camera (for example 22.3 × 14.9 mm for many Canon APS-C bodies). Editing the size switches to Custom; tapping a preset keeps your custom size, and tapping Custom brings it back.
• Pixel size and resolution — pixel size is its own field and presets never change it. Enter pixel size plus either sensor size or resolution, and PlanAstro works out the other so the numbers always agree.
• Field of view — the rig summary shows width × height, worked out exactly from the effective focal length (including any Barlow or reducer). The chart frame, Sky Atlas footprint and Plan It use the same values. Each of the 6 rigs keeps its own camera values, and Premium restores them on your other devices.
• Barlow / reducer — enter the multiplier (e.g. 0.8 or 2.0). Effective focal length, f-ratio, field of view and image scale all update, while your telescope's native specs are kept.
• Mount / tracking — same searchable list. Mount type and tracking style feed the pointing window and meridian handling; strain-wave mounts skip the flip.
• Number fields for coordinates, focal length and sensor size are wide enough that long values never hide behind the little up/down arrows.
• Minimum altitude and Horizon Obstructions — tell PlanAstro about trees, houses and hills so the shaded pointing window is honest.
• Display toggles — in Display → Layers, Lowest usable altitude hides targets below your rig's minimum altitude in the target list and draws a dashed line on the chart, and Horizon Obstructions shades your blocked directions on the chart and hides targets behind them. In My Astro Rig, tap a direction once to block it up to your lowest usable altitude, again to block it all the way up, and a third time to clear it; drag the height slider to set a custom height for that direction. Both start off, so you see every available target until you switch them on; your saved rig values are never changed.
• Connect to mount (live GoTo) is shown as disabled — live control is planned for a later release.

8. Framing and image scale

Once a rig is saved, the chart draws your camera's field of view as a frame you can rotate over any target, and shows arcsec/pixel so you can judge sampling. The framing sliders have large finger-friendly touch areas. Use it to check whether a large nebula fits, or whether you need a mosaic.

Sky Atlas provides Survey Zoom, camera Rotate, Frame Zoom, Shift X and Shift Y; the footprint updates live inside Aladin Lite. On every screen size the Framing Assistant sits below the atlas, leaving the live sky view wider, taller and easier to close.

Mosaic plans targets too large for one frame. In Sky Atlas, pick a grid from 2×1 up to 4×4 and an overlap from 10% to 30%; the panels appear over the target, matched to your rig's field of view. Choose Off or tap Reset to return to a single frame.

9. Conditions, darkness and filters

The Conditions pill opens the night at a glance. Every card expands inside itself, so nothing jumps below or over it. A 🚨 in the banner means there is an alert; tap it for details.

• Weather — six tiles side by side: cloud cover, temperature, humidity, dew point, wind and visibility, with dew advice below. Switch °F/°C, mph/km/h and mi/km right in the card; your choice follows your account. For PlanAstro Premium accounts, Hour by hour details is a dropdown with 6, 12 or 24 hours that stays open while you change range or units, and View full forecast opens the next 12 hours and 7-day outlook inside the same card. It loads by itself once your location is set, retries quietly if the network hiccups, and tells you when it is loading rather than waiting for a tap. A recent forecast is saved against its coordinates so it can return immediately after sign-in while fresh data loads.
• Sky darkness (Bortle) — set how dark your site is; it feeds target recommendations and realistic expectations for faint broadband objects.
• Sky state — daylight, civil, nautical or astronomical twilight, or true dark, for the time you are looking at.
• Tonight's darkness — how many hours the sun stays below −18°, so you know when to do calibration, focusing and framing.
• Moon — phase, rise and set, and how much of the darkness the moon actually spoils, ending in a plain verdict: a broadband night for galaxies and dust, or a narrowband night.
• Filter kit — tick the filters you own, add your own names, and PlanAstro recommends which to use for the night and target in front of you.

10. Sky Atlas and SIMBAD-VizieR

Sky Atlas opens automatically on every object card, shows your camera frame, and aims at the object in that card every time, even after you have opened a different target. It replaces the survey preview with a larger, live Aladin Lite view that starts on DSS2 color. Pan and zoom freely; the Framing Assistant moves the camera frame live.

• Your camera footprint is one true sky-coordinate rectangle inside the atlas. It scales with Survey Zoom and moves with the sky when you pan, so there is no second fixed frame in the center.
• Framing Assistance sits below the atlas. Survey Zoom changes the atlas field; Rotate, Frame Zoom and Shift X/Y update the live camera footprint.
• The survey image credit is bottom-centered so the ICRS coordinate readout remains clear. Aladin Lite's own logo and credit links stay visible and unchanged.
• SIMBAD-VizieR now opens in the same card area with two tabs: Sky shows a live view centered on the object with the same Framing Assistance controls and camera rectangle, and Data shows the professional SIMBAD reference page. Open ↗ remains for browsers that restrict the embedded page.
• The ⤢ button beside those tabs maximizes either sky view to fill the screen; tap it again to restore the card.
• The same atlas is available in Search → Sky Atlas, where Go to my target, Use this view in PlanAstro and Show my favorites link it back to the chart.

Credits: PlanAstro uses Aladin Lite for the main Sky Atlas chart and the object-card framing view. Aladin Lite is developed and maintained by the Centre de Données astronomiques de Strasbourg (CDS), Strasbourg Astronomical Observatory, France. Image Credit: CDS Aladin Sky Atlas / the survey selected in the view. Aladin Lite is free software under the GNU LGPL-3.0-or-later; PlanAstro serves an unmodified copy, and its source is at github.com/cds-astro/aladin-lite.

11. My Archive

My Archive 🗂️ on the chart turns the frames you have already captured into a picture of what you have really imaged. PlanAstro reads each light frame (FITS or XISF) in your browser to learn the target, date, exposure, filter and equipment. For linked cloud folders, one frame per target is downloaded straight into your browser to make a preview thumbnail. Your light frames are never uploaded to PlanAstro servers, and your original files are never changed.

• Connect a source — Local files or a folder from your computer, or Google Drive, Dropbox or OneDrive. Connected folders can be re-scanned at any time with Refresh sources.
• Auto-refresh daily — switch it on and pick a time (03:00 by default) and new frames are indexed without you doing anything.
• Cancel indexing at any time; anything already indexed stays, and nothing is removed from your originals.
• Target cards show total integration time, number of sessions, filters used, imaging dates and a preview thumbnail.
• Search and sort by most integration, newest or oldest imaging date, recently or first added, name, or most sessions; filter by object type and by progress.
• Progress — mark a target In progress, Review or Complete and see the badge on its card.
• Rename any target with a label of your own; the custom name is used in cards, search and Locate, and resets to the catalog name whenever you want.
• Duplicate designations are merged — the same object uploaded as Sh2-155 and as C9 lands in one target folder, keeping both names.
• An archived target that has coordinates but no catalog match is still marked on the sky chart so you can find it again.

12. ISS Tracker

ISS Tracker 🛰️ on the chart is free for every user. It follows the International Space Station live and finds the moments worth photographing.

• A 3D globe shows the station's current position, its ground track from 30 minutes back to 90 minutes ahead, day/night shading, altitude and speed. Drag to rotate, scroll or pinch to zoom, double-tap to recenter, and use Auto-follow to keep the station in view.
• Find ISS passes · next 5 nights lists every visible pass for your location, with times, direction, maximum altitude and brightness. Tap a pass to draw it on the globe; the refresh button pulls fresh orbital data.
• Solar and lunar transits — close approaches of the station to the Sun or Moon are flagged. These last under a second: shoot high-speed video (60fps or more) starting 30 seconds early at 1/1000s or faster, and confirm the center-line on a dedicated transit finder a day ahead.
• Pass imaging — a wide lens on a fixed tripod with 10–30 second exposures gives a clean streak; tracking it manually at long focal length can show structure.

Solar transits require a certified solar filter over the front of the optic at all times. Never point an unfiltered camera or telescope at the Sun.

13. Favorites and exporting

• Favorites 💫 — star objects you want to revisit. Every starred object shows in the Favorites list, whichever catalog name it goes by. Favorites are private and sync across all your devices for every signed-in account.
• Signing out saves your rigs, location, favorites and archive settings to your account first (display settings stay on each device), so signing in on another device brings everything back.
• My Archive — the detailed record of light frames, integration totals and progress, described above.
• High-resolution export — save the current chart, exactly as you have set it up, as a large image for sharing or printing.
• This guide can be shared, printed or downloaded as a PDF from the buttons at the top of the guide window.

14. Comfort, gestures and installing

• Night vision — a red screen mode in Display that protects your dark adaptation at the telescope.
• High contrast and text size controls sit beside it, so the app stays readable in the dark or in daylight.
• Gestures — swipe any panel down from the top of its content to close it, or tap its X. Scrolling, sliders and typing never close a panel by accident.
• Display — Layers is a collapsible dropdown; the Chart symbol key and Deep-sky catalogs sit below it.
• Install it — add PlanAstro to your home screen for a full-screen app that keeps working when the signal at your site does not.

15. Help and support

PlanAstro Premium is $21.50/year for everyone and renews annually at $21.50/year — just $1.79 a month, about the cost of the coffee that keeps you up on one clear night. On the web, subscribe in Menu → Subscription with Upgrade to Premium Now, which opens PayPal checkout and unlocks Premium as soon as PayPal approves it; in the iPhone and iPad app, Premium will be offered through the App Store. Verified Premium accounts display a gold ring and star on their profile avatar across devices. Free access includes the chart, time control, Search with Locate and sorting, Tonight's best for my rig, My Astro Rig, ISS Tracker, the chart symbol key, Location, Conditions summary, Help and My Profile.

Free and Premium: free accounts can use Display in full, open the full object card for any target and set tonight's target. My Astro Rig, ISS Tracker, Search sorting and Tonight's best for my rig are free for everyone. Saved rigs and Favorites sync across devices for everyone. Premium opens Plan It, Browse, the hour-by-hour forecast and My Archive, and syncs account data across devices. Tapping a Premium feature on a free account shows the same feature list as Menu → Subscription.

Sky surveys: Display → Select sky offers Pan-STARRS1 color (the default) plus the other listed surveys. WHAM H-Alpha shows the genuine hydrogen map at wide views and automatically changes to sharp Pan-STARRS1 / SkyMapper detail below 15° rather than enlarging blurry source pixels. Each survey has its credit and a no-endorsement notice in About PlanAstro → Sky Survey Credits.

Menu → Contact Support opens your email app with support.planastro@gmail.com filled in on phones and tablets. On a computer, a message shows the address to email. Write to us with a question, a bug report, an idea or a concern, and we will respond within 24 hours.

16. How accurate is it?

NGC and IC objects come from OpenNGC; other catalogs use their published tables. Chart positions use validated J2000/ICRS degrees. Every identifier that resolves is reconciled against SIMBAD, the professional astronomical database, and its coordinates are used. Objects that could not be confirmed keep their source position and are flagged "Position approximate" on the card. Rise, transit, set, twilight and moon calculations use standard astronomical algorithms for your exact coordinates and time.

17. Tips

• Set your minimum altitude honestly — 30° gives far better data than 15°.
• Plan around the meridian: the hour either side of transit is the cleanest part of the night.
• Use the moon times, not just the phase — a bright moon that sets at 01:00 still leaves a good night.
• Point My Archive at your imaging folder once and let the daily refresh keep your integration totals honest.
• Install PlanAstro from Menu → Install PlanAstro (or the sheet that appears on phones and tablets). After one visit with a connection, PlanAstro opens with no signal: the sky chart, target calculations, your device location and your last weather forecast all work offline. Live weather, the ISS position and new survey pictures update once you are back online.

Clear skies. — PlanAstro