Observed magnitude preferredWe retrieve visual observations from COBS from the previous 90 days, take the median of up to the five newest valid reports, and show the newest report's age. Observations older than 60 days are dimmed to flag reduced confidence.
Estimated magnitude est.When no observed magnitude is available, the session-midpoint estimate is
m = H + 5 log₁₀(Δ) + K log₁₀(r), where H and K are the comet's COBS total-magnitude parameters, Δ is its distance from Earth, and r is its distance from the Sun (distances in AU). If K is unavailable, 4.0 is used.
∞ Beyond 8 AU from the Sun this model stops being a brightness estimate and only extrapolates, so no estimate is shown and the cell reads ∞. Such a comet is far too faint to image; it stays in the list with its position. An observed magnitude, when COBS has one, is still shown at any distance.
Cloudflare WorkerDaily · 18:00 UTC
A scheduled Worker refreshes our comet data fromCOBS. It retrieves active orbital elements and filtered observer reports from the previous 90 days, matches them by comet designation, calculates the median of up to the five newest reports, and stores both datasets in Cloudflare KV. The planner reads this cached result instead of querying COBS separately for every visitor.
·Astro Imaging Planner