# The Gaia-ESO Survey: the inner disk intermediate-age open cluster NGC 6802

Tang, B and Geisler, D and Friel, E and Villanova, S and Smiljanic, R and Casey, AR and Randich, S and Magrini, L and Roman, IS and Muñoz, C and Cohen, RE and Mauro, F and Bragaglia, A and Donati, P and Tautvaišienė, G and Drazdauskas, A and Ženovienė, R and Snaith, O and Sousa, S and Adibekyan, V and Costado, MT and Blanco-Cuaresma, S and Jiménez-Esteban, F and Carraro, G and Zwitter, T and François, P and Jofrè, P and Sordo, R and Gilmore, G and Flaccomio, E and Koposov, S and Korn, AJ and Lanzafame, AC and Pancino, E and Bayo, A and Damiani, F and Franciosini, E and Hourihane, A and Lardo, C and Lewis, J and Monaco, L and Morbidelli, L and Prisinzano, L and Sacco, G and Worley, CC and Zaggia, S The Gaia-ESO Survey: the inner disk intermediate-age open cluster NGC 6802. Astronomy and Astrophysics. ISSN 0004-6361 (Accepted)

Milky Way open clusters are very diverse in terms of age, chemical composition, and kinematic properties. Intermediate-age and old open clusters are less common, and it is even harder to find them inside the solar Galactocentric radius, due to the high mortality rate and strong extinction inside this region. NGC 6802 is one of the inner disk open clusters (IOCs) observed by the $Gaia$-ESO survey (GES). This cluster is an important target for calibrating the abundances derived in the survey due to the kinematic and chemical homogeneity of the members in open clusters. Using the measurements from $Gaia$-ESO internal data release 4 (iDR4), we identify 95 main-sequence dwarfs as cluster members from the GIRAFFE target list, and eight giants as cluster members from the UVES target list. The dwarf cluster members have a median radial velocity of $13.6\pm1.9$ km s$^{-1}$, while the giant cluster members have a median radial velocity of $12.0\pm0.9$ km s$^{-1}$ and a median [Fe/H] of $0.10\pm0.02$ dex. The color-magnitude diagram of these cluster members suggests an age of $0.9\pm0.1$ Gyr, with $(m-M)_0=11.4$ and $E(B-V)=0.86$. We perform the first detailed chemical abundance analysis of NGC 6802, including 27 elemental species. To gain a more general picture about IOCs, the measurements of NGC 6802 are compared with those of other IOCs previously studied by GES, that is, NGC 4815, Trumpler 20, NGC 6705, and Berkeley 81. NGC 6802 shows similar C, N, Na, and Al abundances as other IOCs. These elements are compared with nucleosynthetic models as a function of cluster turn-off mass. The $\alpha$, iron-peak, and neutron-capture elements are also explored in a self-consistent way.