A wet trip

[YKSE]

Friday 9/9,  another chance for dark site trip with C8 before the Moon getting too bright. A little SQM test on zenith of the Moon’s effect, 20.3 when the Moon was 8° above horizon, 20.5 when 7°; and 20.9 when it was totally set.

SQM: 20.9-21.1, average transparency (as the last few day, maybe the high humidity has some negative impact).

Wind 2m/s.

Humidity: 85%-99%, even the mirror diagonal needed dew heater.

NGC 7025, galaxy in Delphinus (mag 12.5, SB13.9). hinted in 72x finder EP, somewhat easier in 123x in averted vision, bright core, about round shape. Invisible when the mag was too high (around 200x).

NGC 7042, galaxy in Pegasus (mag 12.0, SB13.1). AV in 72x, somewhat easier in 123x in AV too , round, Clearly face-on.

NGC 7077, galaxy in Aquarius (mag 13.0, SB12.1). small size(0.8’x0.7’) but relatively good SB, AV in 72x, somewhat easier in 123x in AV too , round shape.

NGC 7081, galaxy in Aquarius (mag 12.8, SB13.1). actually more difficult than 7025, lower latitude might be the cause. AV in 123x, round shape and face-on.

NGC 7137, galaxy in Pegasus (mag 12.3, SB12.9). AV in 123x, round, bright core.

NGC 7177, galaxy in Pegasus (mag 11.2, SB13.0). The easier one for the night, DV in 72x and 123x, bright core, AV showed somewhat oval shape.

The dewing was so heavy that even the EPs in the case in car turnk felt quit wet, had to pack up. Despite a whole night of open EP case, it needed a good sun bath day after to get dry.

[Special K]

Nice observations!  Those are tough targets for sure.  Dew is creeping back into the equation, but you got hit particularly hard!  Hope it's all dried out now  

[YKSE]

Thanks Kevin, it's all dried out now. Never had been this soaked, even though autumn has been quite dewy most of the time.

[Piero]

Nice session Yong!

[FenlandPaul]

Nice report, Yong - some great galaxies around at this time of year.  Dew really seems to be back with a vengeance.

[Stu]

Yes indeed, welcome back dew!

Nice targets Yong, you did well!

[Davesellars]

Nice session on some difficult targets with low surface brightness.  Massive amounts of humidity here as well although no observing for me lately everything for sure everything would have been soaked by the dew monster very quickly.

[YKSE]

Thanks Dave.

I suspect that high humidity is the main reason for dewing, and the larger temperature drop late night in Autumn than Summer or Spring may contribute to it too. I observed comet A8 lenear the other night, humidity was quite high in the early evening too (about 80%), but temperture droped no more than 2° after midnight, and there was absolute no dew without heater.

[alan potts]

Nice report Yong, there are a few there that I have observed myself, that's very high humidity, like being in Singapore.

[YKSE]

Thanks Alan, yes, autumn is the worst dew seaon, this what I did before dew heater