Barnard in time

All stars are supposed to be static in time. No change, no motion, no emotions. But, it is very surprising that a few stars has an abnormally high proper motion. Hipparcos's measurements has revealed of nine fast stars with proper motion over few arc-seconds per year. The fastest known star is Barnard's star. My students of Astronomical practicum has been observed of the field of Barnard's star for two years. Results are just amazing.

Our determination of the proper motion by precise astrometry of five to ten stars per exposure (total 15 - 20 exposures per observation run) gives values:

R.A.: -0.684 arcsec/year, Decl.: 11.660 arccsec/year.

They has been determined as difference of two robust arithmetical means of the star coordinates at Autumn of years 2006 and 2007. UCAC2 was used as an astrometrical catalogue. The values are in really good agreement with values acquired by Hipparcos: -0.79871, 10.33777. The determination of measure errors gives us uncertainty of order of tenths of arcsec. The differences both techniques are a little bit greater. Perhaps, the discrepancy comes due to apparent non-linear motion of Barnard's star and it is illustrated on Hipparcos pages. The periodic differences shows manifestation of Earth's revolutinons around Sun - parallax.

A better visual demonstration of Barnard's star motion exhibits a four-frame animation of observations acquired at MonteBoo observatory over the last years. A single images which has been arranged to film frames are displayed at header of this post. The linked full frame animation shows change of the position of Barnard's star and (of course) some changes in health of our CCD camera. The first image (2001) presents perfect image while the next images (2006) shows two bad-reductable hot columns. The camera has been aged ten or eleven at time of exposure. The last image taken on HaP MK shows absolutely different field orientation and size. All images has been recomputed with respect to first image by rotation, shift and scaling by bi-cubic interpolation (kombine routine from Munipack).

The side product of our astrometry is determination of the focal length of the 40cm telescope of HaP MK Brno to value: 1.7122 +- 0.0007 m.

An another way to illustrate of the Barnard's motion is composition of all images to single frame. In my opinion, this is the most nicer way to present of a proper motion. The original size version.

Visualisation of found stars

A long time, munipack's user calls for better visualisation of data processing. Their flustration probably leaded to creation of clones like CMunipack or some others "data visualisation" utilities. Today, I had uploaded to CVS a small script as a wrapper around ds9. The script generate region file (with a basic overlay graphics elements) for ds9 and invoke one with this file. It plots circles with centres at founded stars (included in .COO file). The circle radius is determined by mphot.opt's parameter fwhm of star or it is defaulty set to 3.


A similar script created Thorman for gaia 6 years ago. Both can be found in script directory. Both will not be instaled by make install. If you want its, copy ones to your */bin directory.

A hang-up under Ubuntu

Today, a hang-up of munimatch under Ubuntu and gfortran compiler has been found during work on processing of globular clusters images. Munimatch hang-ups with the listing on output:

f@filip:/tmp/munipack/munimatch$ mt ref=m5_06R.SRT m5_06V.SRT

Match files : m5_06R.SRT -> m5_06V.SRT

Matrix : 1.0025209128 -0.0000284573
0.0000284573 1.0025209128
Shift : -38.8969865074 18.3495641725
Scale : 0.9975158490

The parent process has been consumed of all CPU time and indicate no progress after a while. Experiments under Gentoo shows equivalent behaviour.

The detailed inspection of source code revealed problem on this line:
do while(.true.)
read(1,'(T7,2F9.3)',end=970,iostat=ii) x,y
i = i + 1
...

The code fails when an error occured (during line read when format is different) and iostat sets error variable to a non-zero value. The replace of the line with equivalent code

read(1,'(A)',end=970,err=970) RADEK1
read(RADEK1,'(T7,2F9.3)',iostat=ii) x,y

corrects of the hung-up problem. The experience shows that the intel ifc compiler, g77 and sun's fortran compilers work without any problems. It may be a bug in gfortran compiler. (Moreover, additional, an index range error has been corrected also.)

Update. The described bug has been corrected. Excellent work! Thank you!

Cfitsio & fortran wrap

Some time ago, I reported problem with compilation of Munipack under Mandriva linux distribution. Today's work under Gentoo make my way where the trouble is occuring. Errors like these:

autoflat.f90:(.text+0x8ee): undefined reference to `ftopen_'
autoflat.f90:(.text+0x93f): undefined reference to `ftghpr_'
autoflat.f90:(.text+0x9da): undefined reference to `ftclos_'

says: You have the cfitsio library installed but the functions has not been found. The problem will appear in "modern" distributions without g77 binary (any f77 compiler), while cfitsio configure script is looking for f77 compiler. If the compiler is not found, the configure-machinery drop off support of f77. It is indicated by:

checking for f77... no
checking for xlf... no
checking for cf77... no
checking for gf77... no
checking for g77... no
checking for af77... no
checking for ncf... no
checking for f2c... no
configure: warning: cfitsio: == No acceptable f77 found in $PATH
configure: warning: cfitsio: == Cfitsio will be built without Fortran wrapper support

It can be easy verified by simple runnig of g77 (f77 will be not accessible).

Workaround

This is a bug in cfitsion library so we will wait for correction by authors (it is done now in cfitsio-3.06, but the correction is not included in "modern" distributions). In meantime, the best solution of this is recompilation of the cfitsio with creation of a "g77" compiler wrapper. The wrapper can be created as a shell script:

#!/bin/sh
gfortran $*

or as link

ln -s /usr/bin/gfortran g77

in any appropriate directory (~/bin,/usr/local/bin) and followed by the complete recompilation of the cfitsio library. This new library .a needs be placed to a system-wide linker path (/usr/local/lib).

The nm utility can help with inspection of the cfitsio library. The gfortran is pretty compatible with g77.