The ATLAS survey discovered an object in Sagittarius on July 1.219 using
the 0.5m f/2 telescope at Rio Hurtado, Chile. This appeared on the NEOCP
as A11pl3Z. MPEC 2025-N12 has just announced this as the third
interstellar object and, what's more, it shows cometary activity:

https://minorplanetcenter.net/mpec/K25/K25N12.html

The orbit, computed by Findorb using the latest astrometry is:

    Perihelion 2025 Oct 29.67795 +/- 0.216 TT = 16:16:14 (JD 2460978.17795)
Epoch 2025 Jul  2.0 TT = JDT 2460858.5   Earth MOID: 0.3549   Ju: 0.2479
q   1.34626730 +/- 0.0133           Ma: 0.0201   Sa: 0.4082      Find_Orb
H   11.91 G 0.15                    Peri.  128.11453 +/- 0.14
z  -3.7575161799 +/- 0.0375         Node   322.06864 +/- 0.10
e   6.0586211 +/- 0.1               Incl.  175.10933 +/- 0.0044
111 of 113 observations 2025 June 14-July 2; mean residual 0".37

The comet is currently around magnitude 18 but could brighten to 15
later in the year. It will be in conjunction on the other side of the
Sun at perihelion but will then move into the northern sky. It should be
observable with amateur equipment for the next year or so. Observations
(astrometry and photometry) of this interstellar object will be
particularly valuable.

There is more information on the BAA forum here:

https://britastro.org/forums/topic/interstellar-asteroid-a11pl3z

What an amazing opportunity to observe a visitor from another star system!

Nick.