Bright Nova in Delphinus

[Mark at Beaufort]

I had a look last night at about 10.30pm and used stars HIP100719 and HIP100500 as a comparison. Both these stars on Stellarium are around mag 7 and to be honest the Nova looked the same. I set up my 15x70 binos on a tripod to get a steady view so I had all 3 stars in the same FOV.

Well even if I am slightly out in my estimate it shows that the Nova is now below naked eye visibility.

Mark

[michael.h.f.wilkinson]

I used HIP100779 (mag 6.4) and HIP100970 (mag 6.9). For some reason the AAVSO chart does not list the magnitudes of HIP100719 and HIP100500. I wonder why. Maybe the proximity of HIP100719 to the mag 5.7 star means it is harder to get a good comparison. I cannot think of a good reason for the latter. When I looked the nova looked distinctly brighter than HIP100970, and somewhat fainter than HIP100779.

[andrew63]

I also looked at HIP 100719 which is listed at about mag 7 in comparison as it's in a good proximity and thought at times that the nova was closer to that than around 6.6. But perhaps the closeness to 5.7 star does have an effect. It is not that easy making judgements for sure.

andrew

[BinocularSky]

the AAVSO chart does not list the magnitudes of HIP100719 and HIP100500. I wonder why.

Ummm....HIP 100719 is variable. HIP 1005000 is listed in teh Hipparcos catalogue as +7.27... (+/- yada yada).

[michael.h.f.wilkinson]

OK, it makes sense not to compare a variable star to another variable

[Mark at Beaufort]

HIP 100719 is variable.

Thanks Steve I was not aware of that. I need more training on viewing variable stars so I can appreciate the changes. Michael is certainly correct not to compare a variable with another variable. Back to the drawing board I think.

Mark

[michael.h.f.wilkinson]

Yesterday evening I estimated it at 6.7.

[bish]

Yesterday evening I estimated it at 6.7.

Same here. Actually had a crystal clear sky for a while. If it continues the same pattern we should be able to see it for some weeks yet.

[michael.h.f.wilkinson]

Just had a look with my APM 80mm at 15.5x with the 31T5, and the brightness estimate is still 6.7, roughly midway between the 6.4 and 6.9 comparison stars. I did a little experiment and inserted a UHC filter in the optical path. The nova suddenly seemed brighter than the mag 6.4 star.

I also had a look at HIP 100719 which is variable with intensities reported between 6.96 and 7.25 (other sources report a variability between 7.01 to 7.14 with a period of 4.9 days). My first estimate is outside that range (6.6-6.7), but the difference in colour and the still slightly blue sky may confuse matters, I will check again later.

[michael.h.f.wilkinson]

HIP 100719 is at 6.9 I would guess. After redoing the estimate when it is dark, I think it is on a par with the mag 6.9 star in the AAVSO chart, and clearly fainter than the nova. The colour difference is striking: the nova is yellowish, whereas HIP 100719 has a blue tint.

[andrew63]

Just had a couple of brief spells between rolling clouds. My estimate tonight would be close to 6.8

andrew

[andrew63]

Nice crisp night... found it about the same around 6.8

andrew

[bish]

Nice and clear here too for a change. I see it as around 6.8 too.

[michael.h.f.wilkinson]

I have just had another look, and put it at 7.0, between the mag 6.9 and mag 7.1 comparison stars on the AAVSO chart.

[bish]

Just come back in. Seemed a touch brighter than a near by 7.1 star - so I make it about 7 or 7.05.

[andrew63]

Yes i would say about 7 also.

andrew

[michael.h.f.wilkinson]

I had a look yesterday evening and put it at 7.1, equal to the comparison star of that magnitude.

[Wyvern]

Been following thread with interest. Looking at my estimates, it appears I'm getting a consistently fainter magnitude result for the Nova than other observers. I must admit this is the first period of mag estimating for a significant number of years... loosing my touch?!!!!! Have always gone for a "quick" estimate though. The longer I take to make a comparison, the harder it becomes to settle on an estimate for the variable in question. Anyhow, for anyone interested, my obs to date all with 7x50 bins are -

25th Aug 21.45UT Mv6.9 - 27th Aug 21.50UT Mv6.9 - 28th Aug 22.26UT Mv 7.0 - 31st Aug 21.10UT Mv 7.1 - 5th Sep 21.47UT Mv 7.4

Regards to all

Les

[andrew63]

Thanks for posting Les - certainly not an exact science, some of my postings have been on the conservative side.

problem with post not going through?

Try again. Just been out at 9 not dark but cloud rolling in. Based on the close stars 80 and 79 I'd say about mag 7.6 tonight.

andrew

[bish]

I managed a really quick look last night and estimated around 7.6 too. There is a 7.1 and 8 star close by that it seemed to be about half way between in brightness.

[bish]

Been following thread with interest. Looking at my estimates, it appears I'm getting a consistently fainter magnitude result for the Nova than other observers. I must admit this is the first period of mag estimating for a significant number of years... loosing my touch?!!!!! Have always gone for a "quick" estimate though. The longer I take to make a comparison, the harder it becomes to settle on an estimate for the variable in question. Anyhow, for anyone interested, my obs to date all with 7x50 bins are -

25th Aug 21.45UT Mv6.9 - 27th Aug 21.50UT Mv6.9 - 28th Aug 22.26UT Mv 7.0 - 31st Aug 21.10UT Mv 7.1 - 5th Sep 21.47UT Mv 7.4

Regards to all

Les

I find the more I look the harder it gets - and it could be that you are just more accurate than the rest!

[michael.h.f.wilkinson]

Last time I had a look was on September 5, when it seemed 7.2, just a bit fainter than the 7.1 comparison star.

[andrew63]

Clear and windy. Based on the close 80 and 79 stars - I'd be in the region of mag 7.8 tonight.

andrew

[michael.h.f.wilkinson]

Dropping rapidly now. I hope I can get a glimpse of it between the clouds

[Wyvern]

Mv 7.9 in 7x50 and tried with 12x50 for a slightly tighter field of view, coming up with same result of Mv 7.9 at 22.14UT on the 9th.