I am delighted to announce that Mike Foylan has discovered his first variable star from Ireland. Mike was using an 8 inch telescope and camera at his observatory near Trim, Co. Meath when doing light measurements of minor planet 3492 Petra-Pepi.
He was testing a software routine within older data when the discovery was made.
The variable star is possibly an eclipsing binary. The star is in the constellation of Ophiuchus with a V-mag of +14.5, its designation is GSC 5065:218. It has relatively short period between 2 and 4 hours. The star can be seen from Ireland this month.

Here is the transcript of alert as follows…

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B.A.A. member Mike Foylan (Cherryvalley Observatory Ireland, IAU
observatory code I83) has reported that he has discovered a new
variable star. Brian Warner (Centre for Solar System Studies - USA)
has kindly provided confirmation observations which show it is
probably an EA type of EB, but we need more observations to confirm
its type and period.

The star in question is GSC 5065-218 which has a mag of 13.96V (APASS)
with a B-V of 0.91. Its position is RA 17h12m29 Dec -0 41' 20".

Observers suitably equipped are requested to undertake time-series
observation (ideally in both B and V) during the current season so
that we can define its type more accurately.

Please post observations to the BAAVSS or AAVSO in the usual way.

Roger Pickard

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Eamonn Ansbro

Congratulations Mike ... a fantastic achievement.

John

Excellent work Mike - MP photometry does have its spin-offs.

This would be a great opportunity for folks here to have a go and get more data. Its easily bright enough for the smaller astrophotography set ups and that should quickly lead to getting the period nailed.

Did you consider sending a submission to AAVSO? I'm not sure of the strength of data required for inclusion in their database (VSX) but I'd imagine even a note to them might result in someone else having a look at what appears to be an easy enough target.

Well done again!
Dave

Congratulations Mike, you're adding to Irelands amateur astronomical reputation.

Paul

Congrats Mike..............in truth I have no idea how much work, checking and rechecking went on at the sharp end of your scope but it must be a fantastic feeling to make such a find. Sometimes hard work (even if we are enjoying it) just pays off. Again....well done!

Good one, Mike, a really good one!

Mark C

Well done Mike, kudos to you! Onwards and upwards.

Seanie.

Well done Mike! Great work!
I'd be interested in seeing your submission.

Hi Guys, many thanks,

Star GSC 5065-218 located in the constellation of Ophiuchus was serendipitously discovered recently while measuring for photometric purposes Minor Planet 3492 Petra-Pepi which was observed originally from Cherryvalley Observatory in May and June of 2011. It was during a testing software routine within MPO Canopus on the June 2011 data when the discovery was made.

Back in 2011 Cherryvalley was only becoming established and submitting astrometric measurements to the MPC. In 2012, Cherryvalley Observatory undertook additional work in photometry on minor planets, I thought I would look at the selection of older minor planet data that I did not worked on for photometric purposes and see for the first time if any photometric data could be extracted and that’s when you come across situations where you say, “Oh, that’s funny”. One of the stars seem to display a ~0.5 magnitude dip, so just to be sure of my own basic analysis I checked the AAVSO VSX database and sure enough no variable star was listed for that precise location and an email was sent to Mr. Brian D. Warner (author of MPO Canopus software) of the Centre for Solar System Studies - Palmer Divide Station, USA and he quickly replied to say “that looks interesting” and he would free a scope for observations on the star in question. A few days later Brian kindly sent me on all his observations and confirmed it was a variable star and probably an eclipsing binary

Next step was to contact the B.A.A. (British Astronomical Association of which Cherryvalley Observatory is affiliated) and informing them of the discovery. Mr. Roger Pickard of the Variable Star Section sent out an alert requesting observations. Although there is only tentative data at the moment the star seems to be an eclipsing binary classed as an “EA” type, The B.A.A.’s describes such a system as…

EA Systems - Algol Type Systems
These are systems in which the light curve shows little variation outside of eclipses. If
there is a significant difference in brightness between the two stars the primary minimum will be marked whereas the secondary minimum may not be observable visually.
The stars in an EA system are spherical and may be well separated or ʻ detachedʼ. They may also be ʻ semi-detachedʼ. In this case there will usually be a mass transfer taking place between the stars of the system. The periods of an EA system can vary from a fraction of a day to years.

So what next? There is an involved process with the AAVSO in submitting a new variable star discovery which needs to be worked through and of course observations from any variable star observers is most welcomed as the exact lightcurve and period needs to be secured.

I would not be at this stage it wasn’t for the help of Mr. Brian D. Warner and Mr. Roger Pickard which to both I am greatly indebted and to Mr. Dave McDonald whom has walked this path before and shown the way for Irish amateur astronomers.

Here is the preliminary lightcurve and finder charts
flic.kr/p/sfAn1w
flic.kr/p/tcmbVh
flic.kr/p/tcDrsP

Mike - the curve you posted looks really good. Its a busy star field alright but well within the capability of a lot of amateurs. Hopefully, enough additional data will be added soon enough to have the EA formally catalogued.

I forget the precise details of communicating with AAVSO but it was easy enough. I registered my details for the VSX database and just uploaded all the data I had. It *is* peer reviewed so I recall it taking a little bit of time for the formal classification to come through. My memory is a bit hazy but I'm pretty sure I worked through Brian Warner too and he put me in touch with one of the AAVSO folks who also guided me on what to do. Brian is a superb resource and any dealings I've had with him, he bent over backwards to help.

Oh yes - I had the "oh, that's funny" moment too! Its so true though...

And you are very kind to mention the path you followed - though I too was also following in the footsteps of others - notably Eamonn Ansbro, others on these board and in Ireland and some international amateurs too. Hopefully, I can resume my journey in the not too distant future. And collaboration with folks such as yourself and others here would be a wonderful thing.

Well done again Mike - richly deserved for the work you've put in over the years. You must be very satisfied.

Dave

Congratulations to you Mike ! Not an easy achievement to reach, well done !

Keith..

Congratulations Mike. I'm strictly a hobbyist and am in awe of the serious work that you and a group of other dedicated observers are doing.

Mike

Just seeing this post today for the 1st time..

Wow, that is brilliant news, congrats Mr Foylan.
I've been speaking with a few people about getting
into the study of variables as they really do fascinate me.

Again, a massive CONGRATS.. Here's to finding some more.
Feel free to contact me as I would love to come on board with you
and 4 eyes are better than 2(Glasses don't count..lol).

Cheers Roy
#ClearSkies

Thank you Roy,
I guess I just got lucky in finding this one. When your undertaking measuring asteroids photometrically to determine their spin rates/amplitude you avoid known variable stars in the field of view as these will skew your photometric results on your target asteroid thus greatly degrading the value of your results.

It’s when you click on a previously unknown variable star and you look at the results you have one of those; “oh, that’s looks strange” moments and then you have to investigate deeper.

Since variable star observing involves specific ways of doing things I guess there is a steep learning curve for me, so I am thinking the best place to start is with short period relatively bright scientifically interesting variable stars and this program from the AAVSO is one I would be definitely interested in called the SPP (Short Period Pulsator) Program which includes a number of RR Lyrae stars and a few delta Scutid stars with large amplitudes with some RR Lyrae stars that exhibit the Blahzko effect as well as some large-amplitude delta Scuti stars that have multiple periods. So it would be great monitoring these stars while not chasing down asteroids.

Collaboration work is the only way to go Roy, its gels people with different skill sets and equipment to work on a specific project in a timely manner otherwise if your doing it by yourself it takes longer (a lot longer sometimes) and can be more frustrating to get the work done.

A recent collaboration project Cherryvalley Observatory worked on was minor planet 4678 Ninian with three other Italian amateur astronomers to determine its spin rate/amplitude which turned out to be around 58 hours, there is no way I could have done this on my own. We hope to have our paper published in the next edition of the Minor Planet Bulletin, so yes working together has great benefits indeed including new friendships, learning from other amateur astronomers and helping you out with observations if the skies are cloudy here, which lets face it is most of the time.

Best wishes and clear skies
Mike

Fantastic news Mike. Great work!

Hi Mike,

Thats a great find. The light curve certainly looks like a EA eclipsing binary. The dip, from your light-curve, lasts about 2.6 hours. So I think the period would be much greater than 2-4 hours. Has anybody else got more data confirming the nature of the body?

I have my CCD camera off the scope at the moment. I had the urge to back to visual observation of variable stars.

Best of luck in your Variable Star endeavours.

John

Hi John
Yes, definitely an EA type, I think the period is indicating 15 hours approx but more work needed, looking through the ASAS3, NSVS and CRTS surveys for data.

Best wishes and clear skies
Mike

Congratulations
Heard alot from Eamonn

Mike,

Have you got a lot more recorded observations from others that might correlate with a better period as compared to an earlier Fourier analysis?
I understand that the period has increased now to 19 hrs from the few early obs of 15 hrs.

Eamonn

Hi Eamonn,
Yes; recent additional high quality observations and compiling older data from other surveys has finalised the period to be 1.2061 days or 28.946 hours, phew, I need a few beers!

Best wishes and clear skies
Mike

I've just seen this - congratulations Mike! it's VERY rare now for an amateuir to be able to discover a new variable, with all the automated programmes using large computerised telescopes in good observing sites, not to mention space observatories like Hipparcos & Gaia! Well done!

Thanks guys

Just a brief update; I am glad to report that the AAVSO has approved this recent new eclipsing binary system discovery with the following message today…
______________________

Dear Michael C. Foylan
Congratulations! Your submission to VSX of the new variable star 'GSC 05065-00218' has been reviewed by a moderator and APPROVED. The data from this submission is now available from the public database. In addition, an AAVSO Unique Identifier (AUID) of 000-BLQ-866 has been assigned to the star, and may be used when submitting observations. Your assistance in making VSX a better tool is much appreciated.

Clear skies,
VSX Administration
______________________

See link for more details…
www.aavso.org/vsx/index.php?view=detail.top&oid=409399

It’s a relatively easy target guys from Ireland so additional observations are always most welcomed.

With best wishes and clear skies
Mike

Cherryvalley Observatory (I83)
Meath.

Hi guys

Now that the dust has settled and the excitement has diminished somewhat I left out (unintentionally and much to my annoyance) a very important aspect of this discovery and that is the team involved in making the results you see known to the wider astronomy community.

I would like to take this (late) opportunity on this forum to say a BIG thank you to Mr. Ale Marchini of the University of Siena whom kindly spent many hours taking CCD images over a number of nights from the University’s well equipped observatory and also spending many hours of his free time analysing the data along with his good friends and very skilled astronomers in their own right; Mr. Fabio Salvaggio and Mr. Riccardo Papini whom also spent many hours analysing and making sense of the data and making it presentable and understandable. Without their help, guidance and advice I would have simply given up. I am honoured and lucky to work with a great group of guys and to rightly give credit for their excellent work and not forgetting Mr. Brian D. Warner of Palmer Divide Observatory based in the USA that helped out with equal enthusiasm.

Please feel free to click on the facebook link below to view the Observatory based at the University of Siena and all the excellent work they undertake including astronomy outreach programs for children and young adults, excellent work indeed. I am sure a simple click on observatory’s “Like” button would be most appreciated by the excellent staff based there.

Facebook link to the Astronomical Observatory of the University of Siena…
www.facebook.com/astro.unisi

Link to Mr. Brian D. Warner’s Palmer Divide Observatory and the excellent research there…
www.minorplanetobserver.com/PDO/PDOHome.htm


As always; clear skies to all

Mike