Amateur Astronomers how many ?

[solissydney]

Is anyone able to give me an educated guess as to how many amateur astronomers
reside in the general Sydney area ?

[AstralTraveller]

Define 'amateur astronomer'.

[tlgerdes]

Practising or non practising?

I would say there would be at least 500 who are members of one of the societies based in Sydney.

[PeterM]

What are you using these figures for would be good and relevant information. As you are with SOLIS maybe its to help with lighting standards and in that case I suppose anyone who looks at the sky with awe and wonder is an amateur astronomer. Thus making many thousands, even the kids who go along to a school organised viewing night, some of whom will be the kids of whom you are trying to impress - and that can have its advantages.
If its to sell/promote something then you are probably only talking in the hundreds who actually put their hands in their pockets.
Use the bigger figure, you can always come down.

[Wavytone]

The real issue is what is the definition of "amateur astronomer"

- have they looked through a telescope in the past 5 years, 1 year, month or week ?
- do they have a telescope ? What about ones who don't, but use other people's at observing nights ?

At least 1000, possibly 2000:

A) the numbers of members in astro societies between the Illawarra and northern Sydney - BTW where's the boundary - including blue mountains, Central Coast up to Newcastle ?

B) for each member of a society there's probably another family member - spouse or kids - sufficiently interested to count;

C) those who turn up at society observing nights, more than once, but aren't members;

D) then there are those who have been in societies long ago but no more (self included) but still go observing or maintain a fair level of interest.

My guess is this group is probably as large if not larger than the combined membership of societies.

E) then there are those we never hear about but bought a telescope. When I realised how many scopes Bintel and AstroOptics sold over the years it was fairly evident there must be quite a large number of people out there in this category. By way of example the numbers that turn up at the Macquarie uni open nights implies this group is large.

[solissydney]

Thank you

Yes, a sizeable estimation could come in handy at some point when dealing with
official bodies when one deals with light pollution.
Iceinspace claims a membership of some 14.000 members I would have thought more like a thousand plus might reside in and around Sydney.
Never mind, this info was just out of interest.

By the way, planning, and testing is under way where app. 45 % of NSW will have its 80 Watt street lights replaced with 18 W LED's with no spill light above the horizontal and with an expected 'option' of a rear shield preventing any light entering private properties should the owner so desire.

[rustigsmed]

Hi Ken,

do you have the spectra data for these LEDs?

Cheers

[Merlin66]

Russell,
If they are similar to the one's being installed in the UK - it's a broad continuum spectrum - no hope of using conventional filters to suppress and sky glow they will cause....
Typical spectrum attached.

[The Mekon]

I have reckoned that you can count 1 serious amateur for every 2000 people in any town or city. On that basis there are about 2000 in the Sydney area.
I reckon there are only about a dozen in my area, which comprises a population of around 20000 in the three towns all within 10km of each other.

[Merlin66]

John,
I think that may be even over optimistic...
That would infer 10,000 "serious amateurs" in Oz.
IMHO it's probably more like 1000 to 2000 in total.
The 10/80/10 ratios - 10% say they're interested but do nothing, 80% are casual observers when it suits them, and 10% are "active".

[solissydney]

Luminaires from three major lighting manufactures are under review in the trail installationes.
So no further info as yet.

[rustigsmed]

thanks for that Ken, that is what I was afraid of ...
Ive heard in the UK (atleast in some boroughs / shires) they turn them off after 10 or 11pm

[dannat]

the other thing is many of the ASV members for instance are members who do not regularly gather photons [either eyes or ccd]through any telescopes, ie they are members for other reasons
i suggest you contact barry clark at ASV..pm me if you want his address details

[Paul Haese]

We have 660 members in the Astronomical Society of South Australia. That is without the probable hundred or so who are not current members. ASV has around 900. So I think 2000 is quite a bit under.

[The Mekon]

South Australia population 1,700,000.
SA astronomical society members 660 (this society has branches in major towns) There are other societies in Victoria other than ASV

So for SA this is a ratio of 1/2575 - not far from my estimate of 1/2000

[Paul Haese]

Yes I know, I was just using those numbers as examples. ;)

[Merlin66]

Membership is one thing, being an "active amateur astronomer" is another.
I still stand by my 10% rule.....