Question about the new LED street lighting

[davelew.livejournal.com]

This is a long shot, but there's enough random information on this community that I thought somebody might be able to help.

The city of Somerville is switching from old sodium vapor street lights to new, more energy efficient LED street lights. That's great and I support it, it's good for the environment and for the city's finances. The problem is with my telescope. I have a filter for my telescope that cuts out light pollution from old-style lights, by blocking light at precisely the wavelengths of the emissions spectrum of sodium atoms. Unfortunately, that filter does nothing for the new LED lights. It's nice to have a filter for urban astronomy if you're looking at anything dimmer than the moon, and I don't know what filter(s) to get.

So, here's my random question: Does anybody know the emissions spectrum of Somerville's new LED lights? Or even a single particular wavelength that they don't emit? I'd even be happy with a model number so that I could contact the manufacturer.

Comments

[http://users.livejournal.com/_meej_/]

I'm a landscape architect who's worked with the City on past projects; these were, as of a few years ago, the "standard" models the City let us know about at that time (public record, so I feel comfortable sharing them). No guarantee they're still current, but I haven't noticed a change in the overall look.