What is galaxy redshift -99.0000?

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https://www.legacysurvey.org//viewer/?ra=339.9581&dec=-45.2941&layer=ls-dr9&zoom=15&sga-parent

it’s quite common to see this value when using the Siena Galaxy Atlas and HyperLEDA/SGA galaxies guides.
Could this be a default value be used when there’s no spectrograph?

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Yep, astronomers have the bad habit of using weird values like -99 rather than NaN for no-value-measured.

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Thank you @dstn

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