NavList:

David P, you wrote:
" It also means the launch is an easterly toss to take advantage of the Earth’s rotation, which makes more sense."

Hmmm. I don't think so. It appears that the launch is for a polar orbit. In fact, the Rocket Lab launch site is ideally suited for polar orbit launches with nice open ocean due south, much like Vandenberg SFB (was AFB) in California. [Of note: there's a polar orbit launch carrying astronauts very soon, and that's a first (no astronauts in the history of the Space Age have flown to a polar orbit, and this is a private space flight, SpaceX rocket and Dragon capsule) but it will apparently launch from Florida and not worry about the slightly less ideal circumstance of flying out over Cuba].

You wrote:
"The only part remaining to be identified is the white dot on the eastern tip of the high ground on Portland Is.  Could that be a star or planet?  The existing lighthouse on the island is supposed to be a tiny affair near the southern tip."

I didn't notice that at all on first pass viewing this image. In fact, I didn't notice Portland Island at all! But yes, that's the island. The white dot doesn't match up with any star, and no major planets would be seen in that part of the sky. It wouldn't take much for a light to be visible there. If its beam is pointed at the camera and given the time-exposure required to trail the stars, it could be a small light. It might even be a mirror of some sort. The rocket launch alone would illuminate a reflective object on the island. I assume they enforce a "no humans" rule on the island during launches, but cameras are probably set up out there to record launches, especially to capture anomalies.

Here's some news coverage on this launch: https://spacenews.com/rocket-lab-launches-fifth-synspective-satellite/.

Frank Reed