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IX Dra: observations requested

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IX Dra: observations requested

IX Draconis is dwarf novae of the ER UMa type. The V magnitude of the star varies between 14.6-18.2 mag. It undergoes very frequent “normal” outbursts, with typical recurrence times in the range 3 to 4 days. Superoutbursts occur regularly with a supercycle length (Psc) of ~ 60 days. Studies have shown that the Psc is increasing.

Recent data from TESS have revealed the light curve of IX Dra in exquisite detail. However, for the next few months IX Dra will not be monitored by TESS. In the meantime, Stewart Bean (BAA VSS) and I are keen to get timings of the start of the next superoutburst (due early November) and possibly the one after that.

Please could observers add IX Dra to their target list. We are requesting one observation per night to get a light curve which will enable us to spot the normal and superoutbursts. Observations can be visual or CCD (Clear is fine, or V) .

Please submit your observations to either the BAA VSS database or the AAVSO’s.

Charts and sequences are available from the AAVSO website. IX Dra is located at RA 18 12 31.47 Dec +67 04 45.8 (J2000.0)

Many thanks in advance,

Jeremy Shears & Stewart Bean.

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Latest results from several observers

The graph summaries the results to date. 

There seem to have been three normal outbursts at 3-5 day intervals reaching 16.5 magnitude (V) at peak. The project is trying to time the next superoutburst to check the apparently regular 61+-2 day period suggested by TESS results. The next superoutburst is likely in the middle of November. If we can maintain observations at this frequency then we will have an uncertainly of only a day of two.  Thanks to all observers who have contributed. Bean data is courtesy of AAVSOnet.

Stewart and Jeremy

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Thanks for the update,

Thanks for the update, Stewart. Certainly a lively star!

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IX Dra

Measured IX Dra at 15.650 CV this evening, 2020/10/22 21:07 UT.

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IX Dra update 23 Oct 2020

Thanks . That fits with the normal outbursts being about 5 days apart before a superoutburst. In the attachment from TESS data you can see the normal outbursts become more intense and 4-5 days separation. IX Dra never really goes into quiescence. Stewart

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Outburst

Yep, certainly in outburst   Oct 22.944    15.4  visual.

Gary

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Graphs missing

Today I noticed the graphs had gone from my posts . I have put the latest back into the 26th Oct post. Any thoughts on the reasons? Are some formats preferred?

Nick James, Gary Poyner and David Swan all report IX Dra at fainter than 17 over the weekend. So back to its low state for a day or so. We can expect a few more normal outbursts at 4-5 day intervals before the super outburst around Nov 14th ( I'm sticking my neck out a bit here, I know).

Stewart

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missing image

"Today I noticed the graphs had gone from my posts . I have put the latest back into the 26th Oct post. Any thoughts on the reasons? Are some formats preferred?"

file size perhaps?  jpg of graphical images tend to be larger and poorer quality than png for example

Robin

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In outburst 27 Oct

Bright tonight: Oct 27.791    15.79C

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Present status as we enter November

The V filter observations graph below shows the current status as we approach an expected superoutburst in roughly two weeks time. With the frequency of observations achieved during this campaign, it should be possible to time the the superoutburst to within one day. This in turn should allow a fairly precise value for the superoutburst period to compare with literature values. The literature graph below implies a supercycle length of about 65 days for 2020 whilst  TESS results, from 2019, suggest 61 days.

The observations below may not be complete so apologies in advance. Six normal outbursts at 5 day intervals  have been recorded. The superoutburst is expected to reach 14.5 during November.

Thanks to all contributing.

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IX Dra in low state. "One week" before superoutburst...

The AAVSOnet SRO telescope in Arizona suggested  a V mag of 17.7  last night - so a low state.

One week to 10 days to go before the super outburst. 

Regards

Stewart

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IX Dra in normal outburst.

ASAS-SN reports IX Dra at magnitude 15.6 in its green channel for 2459162.6 : so back to a high state. When in superoutburst ASAS-SN has recorded magnitudes in the 14.5 to 15 range.

The UK weather forecast seems a bit Novemberish with cloud on all days this week for Cambridgeshire. Fortunately, there is good weather forecast for the AAVSOnet SRO, Arizona telescope for the week ahead.

I'll keep you posted.

Stewart

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Outburst

The LP weather forecast is also a bit Novemberish, i.e. typical for the rainy season.  Tonight is a washout and we will be returning back to the UK on Friday, assuming Iberia doesn't cancel our flights a third time, but I will see what I can do.

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November weather

Conditions in NE England have been terrible over the past week: lots of mist and fog. If the Met Office forecast is right, there may be the odd break over the next few days. I'll be sure to do measurements if conditions permit.

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Bright tonight

I get 14.87 tonight (2020-11-10.8) which is the brightest I've seen it. All of my recent obs are in the VSS database.

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Superhump

Here is one of the superhumps from tonight. Unfortunately the sky clouded over at the end of this run.

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IX Dra 2020/11/10

I measured IX Dra = 14.926 CV at 2020/11/10 22:33 UT.

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Super outburst has been detected

The anticipated superoutburst has been detected. Superhumps are confirmed. I estimate the outburst started at 2459162.5 and should continue for another 10 days or so. I have updated the graph and hope it is fully inclusive for all those have contributed.

The timing of this superoutburst gives an average period for the last 8 outbursts of 59.5 days. This value is close to the last reported value of 58.5+-0.5 from 2010 and suggests that the super outburst period has not really changed in ten years. I will stick my neck out and suggest that the next outburst will start near January 7th.

I think this has been a worthwhile exercise and would wish to thank all who have contributed.

Regards

Stewart Bean

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IX Dra

Thanks for the update, Stewart. It's very nice result and my thanks to our observers, too.

I must admit this is not a star that I have observed before, but I will continue to do so as it's always up to something. I hope others will do the same as we head towards the next superoutburst.

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Other similar targets for the winter

IX Dra has been interesting for a newcomer like myself. It changes every five days or so and puts in a bright superoutburst fairly regularly. Following IX Dra might be a good New Years resolution.

I am going to follow ( from my desk as I do not have my own telescope)  other UGER stars that are high in the morning sky: ER Uma, RZ Lmi, and DI Uma and are starting their observing season. These are also evolving fast enough to be rewarding. Gary Poyner recommended RZ Lmi as it is a good winter target and it has a superoutburst every ~20 days so there really is something happening every few days.

Stewart

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Yes, with ER UMa stars having

Yes, with ER UMa stars having very frequent outbursts, there's always something to see, Stewart. Great fun!

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fading from superouburst

IX Dra is now fading from Stewarts superoutburst.   Last couple of nights...

Nov 14.82   15.3 visual

Nov 16.88   15.49CV

I'll keep going with this one I think.

Gary

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IX Dra Super outburst at 15.3

SRO telescope , Arizona gave 15.3 at  1:33:8.35 UT on November 16, 2020.

Those recorded by TESS were about 10 days in duration from when the first superhumps appeared to getting back to quiescence at mag 17.

Stewart

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Present status as we approach December

The November superoutburst is over,  a return to quiescence at mag 17 and then a rise to 15.9 has been reported by AAVSO observers.

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January superoutburst approaches

The next superoutburst is expected in the first half of January.

IX Dra is now quite a difficult object for the USA based AAVSOnet telescopes that I have been able to use so far, although a couple of AAVSO observers ( Sweden and Virginia, USA) do seem to have reasonable northerly aspects and continue to report. AAVSOnet SRO Arizona is out of service at this time with a failed camera.

UK observers benefit from their higher latitude compared to the USA, but IX Dra  has a very low elevation at this time of year.

If anyone can help for the period from Jan 1st to Jan 15th to capture the start of the superoutburst it would be appreciated. The most likely date for the start is in the middle of the window above - with the usual uncertainties.

Stewart 

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Observations please

A quick reminder that we are only a few days away from the next superoutburst of IX Dra (perhaps 3 to 7 days). Hence observations are encouraged.

I had it at mag 17.1 last night (NY Eve) - just declined from the last "normal" outburst". The next outburst could well be the super...keep watching!

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Obs - -2021-01-02

I have this somewhere around Mag 17.5-17.9 (CV) at 18:45UT this evening (2nd Jan 2021) - not a very accurate measurement as running from Spain with a small widefield refractor, and it's already getting low at dusk - 8 oktas at home...  

(This a single 10min exposure (ED80 + STF8300M)

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Thanks Graeme. That is

Thanks Graeme. That is helpful. Try on other evenings if you can.

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2021-01-03

2021-01-03 1851UT - Better conditions than yesterday (better transparency).

Mag 17.0 (CV)

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IX Dra observations 6 Jan 2021

I am on a couple telescopes in New Mexico in  few hours time. Had no luck with itel Spain owing to "roof closed": clouded out.

Stewart

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DSS image

Have just been looking at where this field is so I can take a quick look with the spectrograph guider from time to time. Impressed by how bright (and blue) it appears in the DSS image

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Spectroscopy and magnitude

Robin , How bright does a star need to be to obtain a decent S/N ratio spectrum?

IX Dra is a bit faint perhaps, but ER Uma is brighter (V mag 13 maximum and better placed for observations ) and also approaching a superoutburst. See Discussion Forum on ER Uma and RZ Lmi.

Stewart

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IX Dra from New Mexico

Sorry Robin : DSS? I'm too new to this topic

I did get an image at 5:30am local from New Mexico and estimate V mag 17.1 +_0.33.

So we seem to observed a normal outburst at mag 16 on the 5th at 2459220.29 recorded by Graeme Coates.

Stewart

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digitized sky survey

Sorry this is a historical observation from the Digitized Sky Survey plates

https://archive.eso.org/dss/dss

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Dec 6th evening

I’ve just imaged IX Dra from my home obsy: mag 17.4C at 17.24 UT

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Morning of 7th

T05 New Mexico gave 17.27 this morning at 2459222.01.

So still in a low state. Graeme Coates measured it at 16.0 on the 5th which may have been the peak of the last normal outburst. So that may mean another 3 days wait.

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I think there were some

I think there were some observations at 15.5 on the evening of the 4th (in the BAA dB) so probably just after peak for my one.

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Long quiescence before superoutbursts

Looking at the last superoutburst graph ( up this forum on Jan 12th ), I see that there was quite a gap between the last normal and  the normal outburst that led to the superoutburst. Immediately after a superoutburst the normals come every 3 - 4 days. Later they seem to be separated by 5-6 days. In the graph on the 12th Jan, it seems that there was a 7 day separation between the last two normals.

On this basis the next normal might be on the 12th. This one might trigger the superoutburst. If so it will be 5 days late relative to the recent long term average.

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Jan 9

Jan 9.771  Mag 15.7 C

looks like a new outburst 

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Just checked my images taken

Just checked my images taken earlier this evening in thick fog. I get 15.4 (unfiltered vs Gaia DR2 G) at Jan 9.73 so it does look like an outburst. Image quality was rubbish though due to the fog. The last decent image I have of the field was Jan 6.73 when it was 17.08.

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Maybe now in superoutbust

Jim deYoung (DEY) reports the following from Virginia USA:

Got IX Dra last two nights, about 2 hours first night then 2.5 hours last night.
Not sure yet if super-humping but it is brighter than the standard inter-outbursts.
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Timing the start of this superoutburst.

Based upon observations from both VSS and AAVSO members, the graph below indicates the onset of the January superoutburst.

I estimate the start time to be JD 2459224.2 which in turn gives a supercycle period of 61.7 days since the November  event. Start times are arbitrary but in the absence of a definition (any ideas?) you have to go with something. The average value for P(sc) is then 60.5 days over the last eight cycles. Variations from this average only seem to be a few days so, with fingers crossed, we can mark our calendars for March 11 for the next superoutburst.

stewart

 

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Timing the start of the March superoutburst.

IX Dra is approaching its March superoutburst. Based upon the current superoutburst period of around 60.5 days ( as described in VSSC 187) March 11 seems to be a likely start date. Yesterday IX Dra was at 17.4 V mag (AAVSOnet New Mexico) having risen from its quiescence low brightness of 18.0. It is possible there will be one more normal outburst and then the superoutburst as the time between outbursts is usually 5-6 days.

IX Dra is really a morning star at present, but is about 40 deg above the horizon at midnight in the UK.

Observations would be welcome over the next two weeks in order to determine the start of the superoutburst within a day.

Thanks in advance

Stewart Bean

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IX Dra now in outburst on March 11 - probably superoutburst

Gary Poyner notes that Yutaka Maeda (Nagasaki, Japan)  has reported the following:

DRA IX    2021 03 10.74591     146:c    Mdy.VSOLJ    outburst

I also just had 14.7 Vmag at 2021/03/11 11:26:17  from itel T11. This compares with 14.5 Vmag for the two previous superoutbursts so most probably a superoutburst.

If anyone has observations for the last few days they could help firm up on the time of the super-outburst's start.

Stewart

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My latest observation was on March 9.8

My latest observation was on March 9.8 when it was 15.39 (ref Gaia G). My data is in the VSS database.

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And 14.89 just now (March 11

And 14.89 just now (March 11.84) in a howling gale.

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March 9.8 at 15.39

Nick, Excellent. I think your observation caught it on the rise to the outburst.  

This fits with the recent average period between superoutbursts of 60.5 days.

Stewart

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IX Dra approaching the next superoutburst

According to the recent trend of 60 days between superoutbursts, IX Dra is due to start its next outburst on May 9th - give or take a few days. 

Last night it was at V mag 16.7 and the day before at 17.8 (AAVSO BSM-NM). So it  may have one more normal outburst before the super starts. 

All contributions welcome to try to capture the time of the next superoutburst.

Stewart

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IX Dra at 18.0 last night

Only 18.0 V filter last night ( New Mexico AAVSOnet) . Probably the minimum before the superoutburst.

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Super outburst may have started.

IX Dra at 14.6 V mag last night (with distinct variations over 15 minutes) which is typical for superoutbursts. Timing is consistent with expectations as described in VSSC 187. Data is at the AAVSO site.

IX Dra does seem fairly well behaved around its 60.5 days super cycle period.

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Super outburst has probably been detected

IX Dra has been observed by AAVSOnet New Mexico scope, in combination with Vphot, as follows.

2021/07/09 03:45   14.57 V

2021/07/10 04:44    14.7 V

These are values consistent with a superoutburst. There has been a week of no observations so the start of the outburst is not yet clear. 

Stewart

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