1. East Asian VLBI activities VERA & JVN KVN CVN VSOP/VSOP2

2. Parallax measurements of H2O maser source beyond 5 kpc with VERA Mizusawa-VERA observatory, NAOJ Mareki Honma & VERA project member

3. Contents Based on astrometry of S269 (at ~5kpc), we present the results on Parallax Proper motions Galactc rotation velocity at S269

4. Star Forming Region S269 S269 : Massive SFR toward anti-center regions Near-IR view of S269

5. VERA array Ishigaki-jimaOgasawara Iriki Mizusawa Max. baseline : 2300 km 2004~ observations started VERA : VLBI array dedicated to astrometry new technology : dual-beam phase referencing

6. S269 H2O maser Intensity 200 Jy Reference ： J0613+1305, (0.7 deg separation) 0.4 mas linear structure with velocity gradient Accretion disk around YSO ? Cross-power spectrum

7. position Parallax measurement Motions of S269 H2O maser East-West motion for 1 yr π ： 189 +/-16 μas D ： 5.30 +/- 0.44 kpc World record for smallest parallax ! 1yr North-South motion for 1 yr

8. S269 in the Milky Way S269 ～ 5.3 kpc c.f. R0 ~ 8 kpc Ready to perform Galaxy- scale astrometry Sun ~30 kpc

9. S 269 proper motion S269 motion with respect to LSR (V_l, V_b) = (-4.6, -4.1) km/s much smaller than galactic rotation (c.f. ~200 km/s) > similar galactic rotation velocity at the Sun and at S269

10. Galactic rotation velocity at S269 Rotation velocity determination from V_l obs. V_l = -5 +/-5 km/s Vc_S269 /Vc_sun = 1.00 +/- 0.03 (accuracy 3% ！ ) Radial velocity is consistent with the above results Tangential vel. Radial vel. Vc_S269 /Vc_Sun Vr, V_l

11. Constraint on the rotation curve Strong constraint from one objects Flat rotation curve out to 13 kpc

12. Summary We have successfully measured the parallax and proper motions of S269 with VERA. Galactic rotation velocity at S269 is the same to that at LSR within 3%. > Strong constraint on outer rotation curve --- these results demonstrate power of high- precision astrometry !

13. Announcement VERA will be open to international use from this observational season (2006/07) Dual-beam mode at 22 GHz will be open. Call for proposal will be in Oct 2006, and deadline will be the end of October. --- If you are interested, please contact us !