Star count survey

[OutThereSomewhere]

A nice clear night in Warrington. Managed to see a total of 6 stars within Orion. I saw more than 16% of people taking the survey. Grrr!

On the plus side, with binoculars, I could see M42 with cyan colouring.

[Nigella Bryant]

7 minutes ago, OutThereSomewhere said:

A nice clear night in Warrington. Managed to see a total of 6 stars within Orion. I saw more than 16% of people taking the survey. Grrr!

On the plus side, with binoculars, I could see M42 with cyan colouring.

I lived in Manchester when at uni suffice to say, "the sky was a nice orange 🍊 colour."

[wulfrun]

Seems very clear here (and very cold), not much twinkling going on. Counted 10, which tells me what I already knew, not a good result. Just spent an hour being irritated by insecurity lights. The most annoying does on-off-on-off ad nauseam because it's close to a boiler flue and can "see" the plume. Aaaargh!

[Knight of Clear Skies]

Counted 27 from the edge of Bodmin Moor, Cornwall. But my nephews counted 18 from inside a town across the river from Southampton, perhaps their younger eyes would have counted more than me from down here?

[Zermelo]

Does anyone know of a translation from the number of stars visible in this count to a Bortle rating?  I know the Bortle rating is a bit more than just NELM (and Orion being low down will affect matters too), but it would be a rough guide.

I did find (and can't remember where) some NELM charts by constellation; these are the ones for Orion:

I counted up the interior stars for each (almost certainly wrongly for the last one), and compared the NELM to the Bortle scale, giving:

Chart  Count   Bortle

<3.5       4           9
<4.5       7           8
<5.5     22           6
<6.5     44           4
<7.5    113          2

If you have done the count already, how does the result in this table tally with your local Bortle rating, if you already know it?
I'm supposedly in a Bortle 4 area and I only managed 10 (!) last night, but I'm hoping for a recount.  I know my eyes are getting on a bit, but I have previously seen stars down almost to mag 6 at this location - although they were higher in the sky than Orion is, and away from the rooftops.

[WiltsStarGazer]

I'm all for raising awareness of the problem of light pollution but the CPRE form doesn't ask for the age of the observer so any information will be skewed by the the deteriorating night vision of the older observers.

Surely if they wanted an accurate picture of the problem, satellite data would give a great deal more consistent information.

[WiltsStarGazer]

Double post, sorry can't see how to delete.

Edited February 11, 2021 by WiltsStarGazer
Double post.

[DaveS]

I had another go last night to see if I could improve on the 23 I saw on Saturday but no luck. I do know (Or at least suspect) that my eyes aren't as good at picking up faint stars as they are with extended sources.

[SuburbanMak]

48 minutes ago, Zermelo said:

Does anyone know of a translation from the number of stars visible in this count to a Bortle rating?  I know the Bortle rating is a bit more than just NELM (and Orion being low down will affect matters too), but it would be a rough guide.

I did find (and can't remember where) some NELM charts by constellation; these are the ones for Orion:

I counted up the interior stars for each (almost certainly wrongly for the last one), and compared the NELM to the Bortle scale, giving:

Chart  Count   Bortle

<3.5       4           9
<4.5       7           8
<5.5     22           6
<6.5     44           4
<7.5    113          2

If you have done the count already, how does the result in this table tally with your local Bortle rating, if you already know it?
I'm supposedly in a Bortle 4 area and I only managed 10 (!) last night, but I'm hoping for a recount.  I know my eyes are getting on a bit, but I have previously seen stars down almost to mag 6 at this location - although they were higher in the sky than Orion is, and away from the rooftops.

This is really interesting thank you for posting - last night from central Winchester I counted 19 (my 11 year old daughter 21)  pretty much spot on your NELM 5 chart above. Theoretically we are Bortle 5 here.

[SuburbanMak]

15 hours ago, wulfrun said:

Seems very clear here (and very cold), not much twinkling going on. Counted 10, which tells me what I already knew, not a good result. Just spent an hour being irritated by insecurity lights. The most annoying does on-off-on-off ad nauseam because it's close to a boiler flue and can "see" the plume. Aaaargh!

If you can reach it there's a "sensitivity" dial on the back of most of them, it's possible to surreptitiously adjust them in the dead of night. Allegedly...

[MartinHiggins]

Well it was very clear here in the middle of Cardiff last night, I think the best it's been since Christmas and I managed 10 stars standing under a street light. 

CPRE says I live in an area of severe light pollution which is kicking a chap when he's down!

 

[MartinHiggins]

1 hour ago, WiltsStarGazer said:

I'm all for raising awareness of the problem of light pollution but the CPRE form doesn't ask for the age of the observer so any information will be skewed by the the deteriorating night vision of the older observers.

Surely if they wanted an accurate picture of the problem, satellite data would give a great deal more consistent information.

Yes that would be more accurate but I guess they wanted to raise awareness of light pollution and get people involved and looking up.

[wulfrun]

1 hour ago, SuburbanMak said:

If you can reach it there's a "sensitivity" dial on the back of most of them, it's possible to surreptitiously adjust them in the dead of night. Allegedly...

Nice idea, unfortunately it'd mean "garden-hopping", it's an adjacent street whose garden backs onto the end of my next-door neighbour's. It's just possible I may have "garden-hopped" in a mis-spent youth (as a prank and not with illegal intent, I might add) but not at my present age thanks. I may go around and ask them, politely, to re-aim/re-adjust it. It's probably coincidence but they do seem always to have it on on cold, clear (astro-friendly) nights but not all nights.

[SuburbanMak]

30 minutes ago, wulfrun said:

Nice idea, unfortunately it'd mean "garden-hopping", it's an adjacent street whose garden backs onto the end of my next-door neighbour's. It's just possible I may have "garden-hopped" in a mis-spent youth (as a prank and not with illegal intent, I might add) but not at my present age thanks. I may go around and ask them, politely, to re-aim/re-adjust it. It's probably coincidence but they do seem always to have it on on cold, clear (astro-friendly) nights but not all nights.

Ha! In the Derby/Notts area we used to call it "cat creeping", like night-time garden parcour in flares. 

[7170]

I'm a bit late to the show but I just managed 12 from here is SW London. Eyes not fully adapted to the dark as clouds just stopped play.