Peter's Variable Star Blog

Bradford Robotic Telescope

2008-07-05T18:31:00.001+01:00

After what seems at least two weeks the BRT is back up and running and ready for jobs to be loaded. I will enter first results received this week.

Regards

SW UMa in outburst....

2008-06-22T18:35:00.002+01:00

The latest news is that SW UMa is in outburst, originally reported by Brian Beesley and further report announcements by Gary Poyner. This object is an infrequent outburster so any reporting on this matter would help both the BAAVSS and the AAVSO. I beleive the last outburst was 2006 July? Will get confirmation of this later today.

Regards.

Still catching up plus....

2008-06-10T21:27:00.002+01:00

I am now at last sifting through the last few events to enable me to post something interesting plus a builder friend is calling tomorrow evening to advise and cost for a brick built observatory attached to the side of the house. This will get me good views North to South East but a very small aperture West with no South to North West views at all. Still everyone has advised me that you get to use your limited area, and learn to use its full capability so I will be able to do some serious work by adapting to my horizon.

Regards

Catching Up...

2008-06-01T18:09:00.002+01:00

Have just finished the treatment for a spinal condition, and the adddition of a heavy workload and I am now trying to catch up with all events of a variable star nature over the last five months. My greatest regret in this is that I missed the BAAVSS / AAVSO meeting at Cambridge Uni. Will post notes and links to this event when I see what is available.

New counter added...

2008-01-01T21:13:00.000Z

After the problems with the site template things are running quite smoothly at present, but the old counter dissapeared so I have added a new one today.

Regards

Z And

2008-01-01T15:55:00.000Z

Z And is causing a stir at the moment, increasing from Mag 11 to 9.7 Eddy Muyllaert and Martin Nicholson to thank for the observations.

Regards

SY CNC in outburst...

2008-01-01T15:50:00.000Z

SY CNC is in outburst at the moment, this is nothing unusual, but the relative groups want observers to contact Gary Poyner if there is any lessening of magnitude, as this is more critical.

Regards

SU UMa

2008-01-01T15:45:00.000Z

Reported by John Toone in December and missed by me until now.

SU UMa is undergoing an outburst. This is significant because it is only the third outburst seen since the present spell of minimal activity began back in April 2007(we have seen three outbursts of U Gem in the same period).29 Nov 2007 1752GMT 14.1 C801 Dec 2007 0539GMT K(1)V(2)M 12.6 C14SU UMa is coming into the "well observed season" but its worth reminding everyone that this star is circumpolar from the British Isles and this outburst can be monitored at any time of the night.

Regards

A most active AGN

2007-12-29T17:47:00.000Z

This is a small article by Gary Poyner regardig one specific AGN but with info that applies to all.

S5 0716+71 – A most active AGN

Active Galactic Nuclei (AGN) are some of the most remarkable objects to be observed in the Universe, and a small number of these are favourite
targets for amateur Variable Star observers. Amongst the brightest and
most active of this group is S50716+71, a Blazar located 5.6 degrees east of the 5th magnitude star TYC 4345 2051 in a rather barren part
of the constellation Camelopardalis at RA 07h 21m 53’.5 +71 20 36 (2000.0). It’s classification was first noted in the fifth 5-GHz strong
source surveys (S5). This survey covers the area between declination 70
and 90 deg. [1] It’s redshift is assumed to be as >0.3 [2], although no precise measurement has yet been obtained.

S50716 is classified as a BL Lac object (or Blazar), a subgroup of the AGN which are radio and gamma ray loud, high energy objects, and display the largest amplitudes of all AGN. Blazars generally show featureless spectra, probably due to the high relativistic beaming found in these objects. It’s thought that this increased beaming, and associated ‘shock waves’ occurring in the jet are the cause of the high variability we see in these objects, and with S50716 in particular!

This high variability proves fascinating to observe both visually and with
CCD’s. S50716 is rarely inactive, and undergoes both ‘low states’ and
outbursts. During March 2004, an historical high magnitude of 12.0 was
reached (which began three months earlier in January), triggering many
satellite TOO’s, especially in the X-ray [3]. Quite apart from periods in
outburst, S50716 also shows easy to detect variations in the order of around one magnitude over the course of several days. This phenomenon has also been observed in BL Lac and W Com, but it would appear to be more
pronounced in S50716, presumably because of the higher relativistic beaming
phenomenon, which is consistent with the ‘shock wave jet’ model. Since the 2004 outburst, S50716 has proved to be more erratic than ever, with the light curve showing just how much this object has been varying from one night to the next [fig.1]. It would appear that the ‘jet’ is almost in a constant state of activity!

As with all Blazars, S50716 shows a high level of IDV (IntraDay Variations, first detected in 1986) in both optical and radio. These small amplitude,
rapid optical variations can be detected with amateur instruments (in V, R and I), particularly when the object is bright. Less common are reports of optical ‘flickering’, but this phenomenon has been detected by experienced visual observers [4].

S50716 is an object which will reveal a high degree of variation to both
visual and CCD astronomers. It’s circumpolar from the UK, and can
therefore be observed all year round. The extreme amplitude varies between 12.0-15.0, but more usually 13.0-14.0, and is therefore quite an easy object for 20-30cm telescopes. It’s variations will keep the observer very much on his/her toes, and is guaranteed to spring a surprise on anyone who observers it for even a short while.

Congrats to Roger Pickard

2007-12-26T17:05:00.000Z

Roger who is the director of the BAAVSS section has been elected to the post President of the BAA.

Congratulations Roger.

Regards

AGN....

2007-12-26T16:41:00.000Z

Just read an article by Gary Poyner regarding Active Galactic Nuclei ?
Very interesting and will post this and other recent matters over the next couple of days.

Regards

OK they say a rest is as good.....

2007-10-01T11:14:00.000+01:00

I will return to posting matters this week after a period of work madness and a well deserved holiday in the lake district.

Regards

Lots of news this week.....

2007-08-18T13:57:00.000+01:00

I have been busy at work again!! Late evenings etc but the VS world rumbles on and there seems to be plenty of activity this week. Nova Vul 2007 brightened to 8.82mag (thanks to David Boyd for the info) but I have not heard any more so I will find out and post tomorrow.
Then there are a list of outbursts monitored by observers using the Bradford Robotic which I am working on this afternoon.
But I really do recommend that people who are interested in the subject sign up for the Yahoo Groups listed below
http://tech.groups.yahoo.com/group/baavss-alert/
http://tech.groups.yahoo.com/group/cvnet-discussion/?yguid=293834643
http://tech.groups.yahoo.com/group/vsnet-alert/?yguid=224356683
http://tech.groups.yahoo.com/group/vsobs-share/?yguid=224356683

Regards

Well I have passed 750 viewings

2007-08-12T10:52:00.000+01:00

Thanks to everyone who visits here... it is much appreciated.

Regards

The Polar project....

2007-08-12T10:23:00.000+01:00

Gary Poyner has actioned an article on the Polar programme (see link) which is of interest, I think this campaign needs as many observers as possible so if you can assist contact Gary a.s.a.p.

http://www.garypoyner.pwp.blueyonder.co.uk/vsspolar.html

Robin Leadbeaters Spectrograph.....

2007-08-12T09:32:00.000+01:00

Robin Leadbeater has kindly allowed me to post the following charts for the spectroscopy for Nova Vul 07.
Spectroscopy to me goes hand in hand with Variable Star Observing and amateaur research and I will try to include more on this subject in the weeks ahead.
The link to Robins page is: http://astro2a.mysite.orange.co.uk/spectra_32.htm

So far this week...

2007-08-11T13:40:00.000+01:00

It has been busy this week, firstly RS Oph had brightened significantly around the end of July, thanks to John Toone for the info and then a major Nova event on the 8th August when Japanese astronomer Hiroshi Abe discovered Nova Vul 2007 which appeared literally from nowhere to a magnitude of 9.4. It then started to fade back to mag 10.
But today I noticed Martin Nicholson has reported that observations from New Mexico are reporting an increase to mag 8.5 then a recession back to ma g9.3, this is certainly an interesting one. Robin Leadbetter who I had the good fortune to meet via the BAA at Northampton has actioned some spectroscopy on this star and I will obtain a copy from Robin and post the contents.

Regards

SDSS1556...When your luck...

2007-07-28T08:26:00.000+01:00

SDSS1556 is in outburst, well would you believe it ! This is one of my four Bradford Robotic items but due to working till late the last three days I had not arranged any jobs. Still as a consolation my copy of AIP4WIN turned up on Tuesday so today I am going to unpack, load the software, and read up on this today and process some images.

Regards

V5558 Sgr (Nova Saggitarius)

2007-07-15T14:12:00.000+01:00

This extract is from the AAVSO site and was a second update after the discovery in April by Yukio Sakurai from Japan.

"V5558 Sgr, a slow nova that has been rising since April(see Special Notices 44, 45, and 48) exhibited a briefbrightening over the past few days, and may now be trendingdownwards. The most recent observations as of this noticeplace the star at V ~ 8.1 at JD 2454280.0 after reachingm(vis) ~ 7.8. Both visual and CCD observers are stronglyencouraged to continue monitoring this peculiar object;BVRI observations are especially encouraged, as they willprovide important information on the spectral evolutionof this nova. We will add comparison stars to VSP if andwhen it brightens beyond the current bright limit of thechart (mag 7.6). We note that the extremely slow novaV723 Cas (Nova Cas 1995) exhibited a short rapid risebefore finally beginning to decline about 100 days afteroutburst, and a similar event may be happening here.Coordinates are: RA 18:10:18.26, Dec -18:46:51.9 (J2000)"

Now currently showing at 6.5mag (sorry) I have just been emailed to say it has faded to 7.5mag this object will make very interesting observing over the next few months...

Regards

Gary Poyner and Uni of Warwick

2007-07-15T07:56:00.000+01:00

The link below is for Gary's interview with Dr Boris Gaensicke as mentioned in an earlier post, highlighting the work amateur astronomers do to help the professionals.

http://www2.warwick.ac.uk/newsandevents/icast/archive/week27/

Regards

Bradford robotic results...

2007-07-15T06:57:00.000+01:00

OK, I am registering these jobs everyday with the above now, SDSS1556, SDSS1637, SDSS1712 and SDSS1730. First results back this morning. This is an ongoing project which I hope to run over the next 6months.

Regards

R CrB (R Coronae Borealis)

2007-07-15T06:40:00.000+01:00

Abstract:

"The Coronae Borealis stars are one of the longest known classes of variable star. They fade dramatically and unpredictably by factors of up to one thousand within a few weeks. Over succeeding months, they gradually recover their original brightness. This spectacular fading is caused by the formation of sooty dust clouds above the surface of the star. The surfaces of CB stars are unusually poor in hydrogen, and rich in carbon and nitrogen, which implies that they are the remnants of evolved stars".

A lot has been going on with R CrB, John Toone reported it varying between 6.1 to 6.4mag in June 2007 whereas it had been at a point of 5.9mag in March to May 2007. A sudden fading is now expected so I will report when this happens to any great extent, Des Loughney in Scotland has reported as I type that it is now down to 6.73.

Keep an watch on this one.

Regards

After an absence..

2007-07-14T11:12:00.000+01:00

I do apologise for the absence of posts but real life matters do get in the way occasionally, will post updates this weekend on what has occured over the last month .

Regards

Bradford Robotic Results

2007-06-04T13:01:00.000+01:00

The BRT was down for about a week so they are catching up at the moment, but I have had the first four results back. Once I have mastered the Java applet to alter the initial .fits file and Maxim DL I will post with results.
Otherwise it has been reasonably quiet on the news front.

Regards

The Bradford Robotic Telescope

2007-05-28T11:59:00.000+01:00

In addition to my visual observing I have started to use the above as an additional project under the guidance of Gary Poyner. I have selected five variables which I will update as jobs on the site for the next few weeks, these are SDSS 2303, SDSS 1556, SDSS 1637, SDSS 1730 and SDSS 1712. I will post on here when I get the first images back and also will show the results of photometry I will have actioned on them.

Regards