Using the website

Search, read a light curve, fold it, and share exactly what you see. Every view is a URL.

API 3.1 · stars release 55c97bc0c218a6c5 · SS release ef7caf53a399bc1f

Search#

The search box is on every page. Choose Stars or Solar System on the home page, or leave the scope on automatic and let the box decide. It recognises these forms:

Solar-system names complete as you type. The first suggestions come from a list of popular names that the page loads when the box first gets focus; the server's matches follow a moment later. Star names are looked up only when you press Enter.

Star names and Sesame#

Your browser sends a star name directly to the CDS Sesame name resolver. It asks three mirrors (CfA, IDIA and CDS) at once and uses the first answer. The Sky Patrol server never sees the name. Then the page:

1. moves the Sesame position to the catalog epoch 2015.5 with the object's proper motion;
2. runs a 10″ cone search;
3. opens the star page if exactly one V3 star lies within 3″, and otherwise shows the 60″ results with the Sesame position marked.

Error messages say what went wrong, for example No V3 stars within 60″ (nearest 74″, g = 17.1) or Name resolver unreachable; enter coordinates.

Cone results#

The results table lists each star's name and id, separation, coordinates, reference g magnitude, number of epochs in g and V, and number of fields. Click a column header to sort. The footer shows the query time, the serve_id and a CSV export. On wide screens a sky image with the result circles sits beside the table; on phones, tap Show on sky.

Star page#

The header gives the star's name, V3 id, coordinates (ICRS, epoch 2015.5), proper motion and reference g magnitude, with links to SIMBAD and VizieR at those coordinates and chips with the star's Gaia DR3 and DR2 ids (each links to the Gaia row in VizieR; hover for the separation and match quality). The Provenance & citation tab repeats the Gaia ids with a copy button, the separations and the Gaia G magnitude. The stat cards show the number of epochs per band, the time baseline, the median and RMS per band, and how many flagged points are hidden.

The light-curve panel has three views:

Time

Magnitude or flux against BJD − 2450000, with calendar years along the top.

Phase

The curve folded on a period you choose, shown over two cycles. You can type the period, nudge it, double or halve it, and set t0 to the time of maximum.

Periodogram

A fast Lomb-Scargle periodogram that runs in the background and can be cancelled. Click one of the five highest peaks to fold on it. The 1 cycle/day and 1 cycle/year aliases are marked.

The toolbar has band chips with point counts, a limits toggle, the Flags menu, an aperture menu (only apertures measured for this star), a magnitude/flux toggle and the download menu.

Reading the plot#

• Colour is band only: g in violet and V in green.
• Shape is status: filled circles are detections, rings are flagged detections (when you choose to show them), and grey down-pointing triangles are 5σ upper limits.
• Error bars are 1σ.
• The plot can highlight one camera or split the curve into one small panel per camera.

Flags menu#

The website starts with the Recommended view, which hides points with any of the bits in 0x17 (bad pixel, saturated, image not marked good, negative pixel). The menu shows how many points each bit hides and offers three presets:

The website default (hide 0x17) is waiting for Ben's approval. The API default hides nothing.

The quality flags page explains every bit.

Downloads#

The download menu fetches the current selection from the API as CSV, ECSV, JSON or Parquet. It can also apply the flags you have hidden as exclude_quality, save the plot as a PNG, give you a Python snippet for the same request, or copy a link to the view. The Provenance & citation tab lists the release id, serve_id and the text to cite.

Tabs below the plot#

Measurements

Every row of the light curve. Selecting a row highlights its point and clicking a point scrolls to its row. Flag chips explain each bit.

Fields & cameras

The ASAS-SN fields and cameras that observed the star.

Provenance & citation

Release ids, decoder version and citation text.

Solar-system pages#

The Solar System landing page has the search box, featured objects and the objects you viewed recently. An object page shows its name, orbit class, orbital elements (a, e, i), H and G, other names, and links to JPL SBDB and the MPC.

The light-curve panel has three views:

Observed

Magnitude against JD − 2450000 (UTC).

Phase curve

The reduced magnitude m − 5 log₁₀(rΔ) against phase angle α, with an H, G fit. For comets the page plots m − 5 log₁₀Δ against r instead.

Residuals

Observed minus the H, G model against time.

Controls choose the bands, the product (reduced images as filled points, difference images as rings), the aperture (six radii from 0.75 to 3 pixels) and the light-time correction. Notes about the object, such as blend or comet warnings, appear above the plot. The solar-system data page explains these choices.

The orbit panel draws the Sun, the planets, Earth, the object's orbit and the line of sight for each night it was observed, seen from the top, tilted or edge-on. The timeline below works as a slider and can play the observations in order. Hovering over the light curve, the orbit or the sky panel highlights the same night in the other two.

The tabs below are Measurements, Observing geometry (r, Δ, α and solar elongation against time, with low-elongation periods shaded), Notes and Citation.

Sky panel#

The sky panel uses Aladin Lite with Pan-STARRS images north of Dec −29.5° and DSS2 elsewhere, in a 4′ field. It loads after the light curve, and on phones only when you tap it. A star page marks the target, the ASAS-SN apertures (8″ per pixel) and neighbouring V3 stars, which you can click. A solar-system page draws the object's track coloured by time. If the image servers fail, the panel says so and offers a retry; the overlays keep working.

URL parameters#

Every control updates the URL, so a link or a bookmark reopens the same view. Parameters you leave out take their defaults.

Star pages: /star/<star_id>#

An AV3 name in the path, such as /star/AV3_085448.87+200630.6, is replaced by the id. Cone results live at /stars?ra=&dec=&r= (with q= when the search started from a name), so reloading the page does not repeat the name lookup.

Solar-system pages: /ss/<slug>#

Slugs are the number for numbered asteroids (20), the designation with underscores for comets and unnumbered objects (2P, C_2020_F3, 2019_AB1), or id-<object_id>.

Plot controls#

Keyboard shortcuts#

The plot also has a text summary, and the Measurements table holds the same data for anyone who cannot use the plot.

Privacy#

The service records IP addresses, approximate geographic locations and requested sky coordinates in private operational logs. Accounts use secure session and CSRF cookies. Your browser also stores the colour theme, dismissed banners, recently viewed objects and the fastest image mirror. Account actions and data queries go to this service; star-name searches go to Sesame, and sky images come from the image servers. See About.