Since its start, the GALAH survey has aimed to collect a sample of one million stars. The data in GALAH DR4 were collected between 16 December 2013 and 6 August 2023. In that time we have acquired 1,085,520 spectra of 917,588 stars. This page presents the observing progress of the GALAH survey.


Fields observed

Location on the sky of all the fields observed as part of the GALAH Survey. Location on the sky of all the fields observed as part of the GALAH Survey. Each small circle represents a possible field, with those highlighted having been observed. Fields from other programs are shown in purple.


Number of stars observed

Cumulative sum with time for the number of spectra and the number of stars. GALAH DR4 contains 1,085,520 spectra of 917,588 stars. This histogram shows the cumulative sum with time for the number of unique spectra (flagged and unflagged) and the number of unique stars (flagged and unflagged). “Unflagged” refers to those targets for which there is no problem noted with the reduction. The vertical grey stripes indicate observing nights.


The cumulative number of spectra acquired for each sub-survey. This histogram shows the cumulative number of spectra acquired for each sub-survey within GALAH (Phase 1, bright targets, faint targets, Phase 2, K2-HERMES, TESS-HERMES, and other programmes). The colour coding is the same as in the all-sky map of observed targets.


Observing time

The cumulative nights on sky used by the GALAH Survey. The cumulative sum of total observing nights used by the GALAH Survey. The vertical grey stripes indicate observing nights.