Trouble with a FITS file

[Mikael]

Hi!

My name is Mikael, I'm 18 years old and I'm pretty new to astronomy.
As it happens, I was lucky last year and I was granted observing time
at the Nordic Optical Telescope (2.6m), La Palma. At the NOT I
observed a planetary transit of WASP-12b with the ALFOSC instrument
and I also did some spectroscopic measurements at the velocity
extremes and mid-transit with the FIES spectrometer. My trouble is the
reduction of the photometry. I have tested about 4 different reduction
softwares (proprietary as well as open/free), but none of them is
willing to accept the FITS files. I have uploaded one of the 800
exposures made that night. Something is wrong (not with your software,
since the files don't seem to work with any other ether), but I don't
have the proper knowledge about these things to be able to figure it
out myself. Could someone please take a look at the file and see if
you can detect anything out of the ordinary with them? Just tell me if
you need anything more (like more exposures, flat, bias).

Thanks in advance!

/Mikael

[Joao Gregorio]

Mikael,

I just openned it with DS9 and it did open.
The fits header looks ok, except the number of axis is 0 (zero) I
think it should be 1 or 2.
What software did you use to open it?

Joao Gregorio

www.atalaia.org/gregorio

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[Filip Hroch]

Hi All,

The file ALsl060094.fits looks as proper FITS file. To check if really
is, try the FITS verifier:

http://fits.gsfc.nasa.gov/fits_verify.html

(it passed correctly for me).

The file has two parts:

1. the header only with a metadata but without an image

2. the image itself

The structure can be understand in the verifier but also in
xmunipack where tree-like structure shows the header and the data.
I also confirms, it works under ds9 or gaia.

By my oppinion, the non-plain structure of FITS files is common
for many professional applications of FITS due support to
store of different types exposures (biases, flats,..)
or spectral bands etc. in a single file.

Unfortunatelly, Munipack doesn't supports manipulation with
the types of FITSes directly. So you have two ways:

* Select only the image from a file with help of operator [].
Example:
ds9 '/tmp/ALsl060094.fits[im1]'

* Copy out the image by using of FTOOLS:
http://heasarc.gsfc.nasa.gov/docs/software/ftools/ftools_menu.html
http://heasarc.gsfc.nasa.gov/lheasoft/ftools/fhelp/fcopy.txt

FH

[Joao Gregorio]

Filip and Mikael

The Fits has two fit header's. It shows both in FV (Fit Viewer), one
has NAXIS=0 and the other NAXIS=2

IRAF gives an error message: ERROR: FXF: must specify which FITS
extension (ALsl060094.fits)

GAIA from Starlink opens a popup to chose which header to open and
after that it opens the FITS file.

If we change the NAXIS =0 to =2 it may work...its just a guess.

Joao Gregorio

[Mikael]

Thank you all!

I know ds9 has no problem at all with opening it, but other
(reduction) software seem to have some.

My first try at reducing the data I did using Maxim DL 5.07
(proprietary), but an error message just showed up when I tried to
import the data. I've used that software for reduction before (with
another set of data form another instrument) and it has worked just
fine.

I will test changing NAXIS =0 to =2 and see if that does the trick,
and reduce it all in an open environment using open tools.

I'll keep you posted on my progress and feel free to check out my blog
for the project: http://extrasolar-planets.blogspot.com/

Thanks!

[Joao Gregorio]

Mikael,

MaximDL must be confused by the double header, I also tried IRIS and
it also failed to open with error AXIS =0

If you have linux try GAIA, it opens the file and has a photometry tool.
http://starlink.jach.hawaii.edu/starlink
http://starlink.jach.hawaii.edu/starlink/NanahopeDownload

I'm also into exoplanets, I'm part of the XO-Project colaborating in
the Extended Team and co-discoverer of XO-4 & 5

Joao

[Joao Gregorio]

Mikael,

I'm not sure if GAIA can handle reduction of the images, I don't use
it for that pourpose and I don't remember to see it in the menu..
So my hint was wrong...sorry, it must be the double header.
I'm at work now and can't fidle with GAIA to see if there is a way to
convert the frames into a "proper" format with only one header.

I'm trying to observe Wasp-12 since it started to be in position, but
the weather is bad for months now.

Joao

On Thu, Jan 14, 2010 at 3:42 PM, Mikael <ing...@gmail.com> wrote:
> Joao,
>
> Cool! In the selection process for a candidate for the observation
> some of the XO-planets were in serious consideration! Finally I
> settled with WASP-12b part of because it would undergo transit both
> nights I had been granted (6-7 and 7-8 Dec).
>
>
> I changed the NAXIS from 0 to 2 in the header where it said 0, but it
> didn't appear to help.
>
> Is GAIA useful for the complete reduction (making of master bias and
> flat, subtract them etc?)
>
> Is there any easy way to just change the header (into one) with all
> the necessary info in them (I'm talking about 800 exposures)?
>
>
> Thanks,
> Mikael

>
>
>
>
> On 14 Jan, 14:41, Joao Gregorio <ct1...@gmail.com> wrote:
>> Mikael,
>>
>> MaximDL must be confused by the double header, I also tried IRIS and
>> it also failed to open with error AXIS =0
>>

>> If you have linux try GAIA, it opens the file and has a photometry tool.http://starlink.jach.hawaii.edu/starlinkhttp://starlink.jach.hawaii.edu/starlink/NanahopeDownload

[Mikael]

Joao,

Cool! In the selection process for a candidate for the observation
some of the XO-planets were in serious consideration! Finally I
settled with WASP-12b part of because it would undergo transit both
nights I had been granted (6-7 and 7-8 Dec).

I changed the NAXIS from 0 to 2 in the header where it said 0, but it
didn't appear to help.

Is there any easy way to just change the header (into one) with all

the necessary info in them (I'm talking about 800 exposures)?

I'll try GAIA out and see it it does the trick. I would rather use
open source software instead of Maxim DL, part of because science has
to be reproducible (which it's not if you use proprietary software in
the process).

Thanks,
Mikael

On 14 Jan, 14:41, Joao Gregorio <ct1...@gmail.com> wrote:

> Mikael,
>
> MaximDL must be confused by the double header, I also tried IRIS and
> it also failed to open with error AXIS =0
>

> If you have linux try GAIA, it opens the file and has a photometry tool.http://starlink.jach.hawaii.edu/starlinkhttp://starlink.jach.hawaii.edu/starlink/NanahopeDownload

[Joao Gregorio]

Mikael,

I've tested a few softwares, I found munipack and c-munipack and
started to use them.
You have GCX for linux, it also does reduction but doesn't handle 2 headers.
Still, for now, C-munipack in windows and Munipack in ubuntu are my favorites.

Joao

[Mikael]

Yep, it's the two headers causing the problems. GCX (as you said)
can't handle the two headers (just says "error opening the file"), but
Munipack for Ubuntu does? I've had some problems with it (it says the
tools for making master flats etc. are unavailable and that Munipack
maybe isn't installed correctly, and still I've added the directory to
the binaries's search path, I think).

The observations of the WASP-12b transit were made over a period of
about 6h and the exposure time was changed (from 10s to 9s because it
was beginning to saturate). Can Munipack handle that kind of a problem
too?

/Mikael

On 14 Jan, 17:06, Joao Gregorio <ct1...@gmail.com> wrote:
> Mikael,
>

> >> If you have linux try GAIA, it opens the file and has a photometry tool.http://starlink.jach.hawaii.edu/starlinkhttp://starlink.jach.hawaii.e...

[Joao Gregorio]

Mikael,

Filip is the right person to answer that question about munipack.

Joao

[Joao Gregorio]

Mikael,
are you using ubuntu?

If so, there are a few requirements needed.
see the....
Step by step for Debian & Ubuntu
....on the webpage

Joao

--
www.atalaia.org/gregorio

[Mikael]

I used a script written by my programming teacher, which followed the
procedure described on the website. I have uploaded the script, feel
free to check it out.

/Mikael

On 15 Jan, 11:40, Joao Gregorio <ct1...@gmail.com> wrote:
> Mikael,
> are you using ubuntu?
>
> If so, there are a few requirements needed.
> see the....
> Step by step for Debian & Ubuntu
> ....on the webpage
>
> Joao
>
>
>
>
>
> On Thu, Jan 14, 2010 at 8:50 PM, Joao Gregorio <ct1...@gmail.com> wrote:
> > Mikael,
>
> > Filip is the right person to answer that question about munipack.
>
> > Joao
>

[Filip Hroch]

Hi Mikhael,

I understand that your are trying graphical interface for Munipack
(xmunipack) which have no implemented the reductions yet. But, you can
use command line interface. Firtsly, be sure that you have necessory
tools in the path:

bash$ export PATH=$PATH:/opt/munipack/bin
bash$ darkbat
....

and than follow the tutorial:

http://integral.physics.muni.cz/munipack/tutorial.html

Please, fill a bug tracker on googlecode or send it to this list,
if you found a problem.

I think that the graphical interface is extraordinary usefull and
preparing it, but it is not finnished yet.

FH

--
F. Hroch e-mail, jabber: hr...@physics.muni.cz, tel.: +420549494470
Dept. of theor. physics and astrophysics, MU Brno, Kotlarska 2,CZ-611 37

[Filip Hroch]

It's looking good! Thank you (or your teacher;).

Can I publish it?

FH

[Mikael]

I asked him (his name is Johan Arvelius) and he said that it's OK!

[Mikael]

Problem solved and the reduction went fine. It was the double header
making the fuss. I used a script that imported the time of observation
and exposure time from the first header to the second header and then
just deleted the first header, leaving one header intact with the
useful info. After that the reduction went fine and my result can be
seen here: http://extrasolar-planets.blogspot.com/2010/01/first-reduction-of-not-data.html

I will of course announce ETD with my paper when it's finished. One
interesting thing is that ETD says that WASP-12b causes a 15mmag drop
in brightness, but my data from the Nordic Optical Telescope clearly
states 16mmag, which is unlikely to be wrong. What do you think? Is it
within the error margin or is this my contribution to the advancement
science perhaps?

Thanks for all the help!

/Mikael

[Joao Gregorio]

Mikael,

excellent observation, very low scatter. Congratulation on that superb LC.
The difference you find it's within what we can expect to have,
specially if it's from different filter's.

Joao

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