In a shallow near-infrared survey of the dwarf irregular galaxy, NGC3109, near the periphery of the Local Group, we have found eight Mira variables, seven of which appear to be oxygen-rich (O-Miras). The periods range from about 430d to almost 1500d. Because of our relatively bright limiting magnitude, only 45 of the more than 400 known carbon stars were measured, but none was found to be a large amplitude variable. One of the Miras may be an unrecognized C star. Five of the O-Miras are probably hot-bottom burning stars considering that they are brighter than expected from the period-luminosity relation of Miras and that, by comparison with theoretical evolutionary tracks, they appear to have masses >~4M_{sun}_. A census of very long period (P>1000d) Miras in the Galaxy and Magellanic Clouds is presented and discussed together with the newly discovered long-period, but relatively blue, variables in NGC3109. New JHKL photometry is presented for three O-rich long-period Miras in the Small Magellanic Cloud (including a candidate super-AGB star).

Cone search capability for table J/MNRAS/483/5150/table1 (JHKS photometry of nine large amplitude variables)

Cone search capability for table J/MNRAS/483/5150/table2 (Very long period variables in the LMC)

Cone search capability for table J/MNRAS/483/5150/table3 (SAAO JHKL photometry of SMC variables (all O-rich))

Cone search capability for table J/MNRAS/483/5150/tablea1 (JKS and Gaia (BP, RP) photometry of LPV in LG Galaxies)

Cone search capability for table J/MNRAS/483/5150/tablea2 (JKS and Gaia (BP, RP) Photometry of supergiants and S stars in LG Galaxies)

Cone search capability for table J/MNRAS/483/5150/tc10 (Photometric data for NGC 3109)