About Astrojohn

I am a science geek! Interests Astronomy, Skiing, Philosophy, basically any form of technology including writing automation software for my observatory. I will also share this with others using the same EQMOD/Astroart tool set.



Observation Manager Click to join AA5ObsMgr

Click to join AA5ObsMgr

Variable Star V0470 Cam – Interesting Light Curve

Light Curve

Light Curve


This data taken 12 November 2017 -(Data points on BAA Site)

But interesting shape of curve.  You can see the secondary eclipse of the dimmer and smaller star.


Part of the Veil Nebula – Moon 75%!

Veil nebula is a cloud of dust and ionised gas (Sulphur Oxygen and Hydrogen) in the constellation of Cygnus.  It contains a radio source and is about 1470 light years away.


Veil Nebula

Even more accurate binary data using AA6 SP3 and new camera.

UX UMA new data using new camera and new software AA6 SP3.


The zero point is Mag 14 the time is 2017-08-27T 23:16:19.5′ / LT for start of image exposure 80sec.  The orange is the check star.  The measurement is done against 3 reference stars from AAVSO.

V Filter (Green) and the setup was Camera Trius H694 and 8inch RC Astrograph from Altair Astro.

This is quite a fast orbital period at 0.19 days.

UXUMA 13 36 40.9 +51 54 49.5 Max12.57 Min14.15 P= 0.19667128 Type=EA/WD+NL

Algol Type EA

Algol (Beta Persei)-type eclipsing systems. Binaries with spherical or slightly ellipsoidal components. It is possible to specify, for their light curves, the moments of the beginning and end of the eclipses. Between eclipses the light remains almost constant or varies insignificantly because of reflection effects, slight ellipsoidality of components, or physical variations. Secondary minima may be absent. An extremely wide range of periods is observed, from 0.2 to >= 10000 days. Light amplitudes are also quite different and may reach several magnitudes.


Systems with white-dwarf components.


Novalike variables, which are insufficiently studied objects resembling novae by the characteristics of their light changes or
by spectral features. This type includes, in addition to variables showing novalike outbursts, objects with no bursts ever
observed; the spectra of novalike variables resemble those of old novae, and small light changes resemble those typical for old
novae at minimum light. However, quite often a detailed investigation makes it possible to reclassify some representatives
of this highly inhomogeneous group of objects into other types.

New software AA6 and Observation Manager script has improved accuracy.

The original data (images) have been re-scanned using new script.

UX UMA variable star.  14/8/2017


Captured an eclipse of a binary star system 13 years ago!

Yes, we are looking back in time for every star we observe. This one is designated UX Uma, in the ‘Plough’.
The binary star system is 13.06 Light Years away. So last night I watched as a smaller dwarf star passed in front of a larger star but they are very close together. So my telescope is really a time machine looking back 13 years.
This image is the dimming of the larger star by a smaller object passing in front.

UX Uma 14-6-2017

UX Uma Plot from RAW data


So this happend 00:25 local time (Selsey UK) but really 13 years ago!

Astroart6.0 SP2 is available! With scripted auto photometry for variable stars.

Yes, with a simple script you can image the variable stars, using a list of variables and reference/check stars you can produce your BAA or AAVSO reports direct.  Either at the time of imaging or as two separate processes.  It is really great and many thanks to the guy’s at MSB (Astroart software team) http://msb-astroart.com for the work required to produce these new script commands…. So simple to do now:

Load the image
…just to check that AA6 found them all!! You can check which one it did not with another script command.
calcmag = Image.stars.mag(1)
snr = Image.stars.sn(1)
adu = image.stars.adu(1)
Where VarRef.txt contains your text file of variable RA DEC and three reference stars RA DEC and Mag. Then one check star if required. For all your variables that you follow. The software does the rest!

Great for fast time series. could process 100 measurements in about as many seconds.

If anyone would like a custom script written to capture process and measure stars I am happy to help.
I have now tested the BAA bulk transfer software to upload the report. I also have the format in script for the fast time series. Don’t forget that the Julian time is at the CENTRE of the exposure not the start as in the FITS header.I also have the script code for that!!

All bits I had to find out and learn with the help of Andrew Wilson the BAA database manager.

Interesting that a medium sized telescope can find objects orbiting stars 880LY away!

Yes, this is the result of a star measurement session. A time series of V filtered measurements of RW Tri at 880LY.
From this information you can estimate sizes of objects and rotational period.

RW Tri

RW Tri Time Series.

It is 2017 and to start the New Year– Orion Nebular!

I just love this nebular.  Star forming area of dust and gas. This is a better image than before Xmas.
Two sets of exposures to get the core and the dust areas.

Techy bit:  3 x 100sec per RGB and 4 X 130sec L  merged with 3X 60sec per RGB and 4 X 60sec Luminance. Taken with 8inch RC astrograph with a Trius H694 camera running ar -12C. Filter system is StarlightXpress Mount is AzEq6 pro.

Orion Nebular

Orion Nebular


Cacoon Nebula 8 Sept 2016

Ok I have taken quite a good image of this tricky nebula.
Take a look on the web and look at some of the images.
4 X 400sec per RGB.  No darks. (had to manually take out a couple of hot ones)

RGB Image of Cacoon Nebula

RGB Image of Cacoon Nebula

M51- Good seeing and good target

My image of M51 in colour came out really well:

M51 Colour

M51 Colour