Krioma.net

An image taken of the galaxy M86 in the [Virgo cluster of galaxies]...

(a 30s B filter image taken at Wast Hills)

The University of Birmingham's optical telescope at [Wast Hills].

I decided to put a little bit of python code together as a demonstration of how to define a function by calculating the blackbody curve of an object (see the bottom of the entry if you want to know what this is), anyway I thought I'd share this little snippet of code.. its not anything particularly outstanding but tis neat. How to define a blackbody:

def blackbody_at_f_t(freq,kB,T,c,h): #T in K, f in Hz return 2*h*(freq**3)/(c**2)*(1/(exp((h*freq)/(kB*T))-1))

You just need to pass freq - the observing frequency (in Hz), kB - the Boltzmann constant (in J/K), T - the temperature (in K), c - the speed of light (in m/s) and h - the Planck constant (in JS). This show just how simple python can be to define a function. Below is an example of actually using this, and of course we can nicely vectorise things too... and plot!

def blackbody_at_f_t(freq,kB,T,c,h): #T in K, f in Hz return 2*h*(freq**3)/(c**2)*(1/(exp((h*freq)/(kB*T))-1))

#Python Libraries
from pylab import *
from scipy import *
from numpy import *

#constants
kB=1.38066E-23; # Boltzmann's constant in J/K
c=3.0E8
h = 6.63E-34 #Planck's constant (JS)

logspace = 10.**linspace(1.0, 20, 5000) #logspacing of frequency
T =2.715 #K cosmic background radiation
out = blackbody_at_f_t(logspace,kB,T,c,h)
fig = plt.figure(figsize=(6, 6))
ax1 = fig.add_subplot(111)
plot(logspace/1E9,out,'r-',markersize=0.5)
ax1.set_xlabel('Frequency (GHz)', fontsize=10); ax1.set_ylabel('Energy Density (J/Hz)', fontsize=10)
xlim(0.0,800)
show()

The whole above code can be found in [blackbody.py]

and you end up with blackbody curve of the cosmic microwave background:

A black body is a theoretical object that absorbs 100% of the radiation that hits it, hence it appears to be black. Due to this nature its also a perfect emitter of thermal radiation. which it radiates in a characteristic spectrum that depends on the body's temperature - as can be seen above for the cosmic microwave background. If you want to know more about the cosmic microwave background try [here]

The Constellation of Cassiopeia taken with the Bradford Robotic Telescope, follow the link and you can see the excellent job astrometry.net did on finding all the stars (there is a nice overlay).
It even found stars that are obscured by the telescope - it uses patterns of stars to recognise parts of the sky so once it found the distinct 'w' of cas it was able to place positions for the rest. Pretty cool.

On August 23rd a star in the [Pinwheel Galaxy] (M101) perished in a supernova explosion. At 21 million light-years from Earth this is the closest star explosion of its type observed since 1986. The object, SN 2011fe, has brightened so much that it is now possible to view with binoculars ([instructions on how to observe]). On 8th September, astronomers (Dr Samuel George, Elizabeth George and Richard Pearson) using the [University of Birmingham Observatory] on a cloudy night managed to take an image of the galaxy clearly showing the supernova (as indicated by the target symbol):

We took a [colour image of M101] a while back and here (on a similar scale/rotation) is a comparison pre-and-post-supernova:

As an astronomer a fast an easy way to calculate the Julian date of an observation is always handy. As I'm currently doing a bunch of python demos and adding some new libraries to some of my tools I though I'd share this one. Oh and if the first sentence confused you: The Julain date or JD is the the interval of time in days and fractions of a day since January 1, 4713 BC Greenwich noon. Now this is how you calculate it:

def julian_date(YY,MM,DD,HR,Min,Sec,UTcor): return 367*YY - (7*(YY+((MM+9)/12))/4) + (275*MM/9)+ DD + 1721013.5 + UTcor/24 - 0.5*sign((100*YY)+MM-190002.5) + 0.5 + HR/24.0 + Min/(60.0*24.0) + Sec/(3600.0*24.0)

So all you need to do is supply the year (YY), month (MM), day (DD), hour (HR), minute (Min), Second (Sec) and the time difference from UT (UTcor) and their is your JD. So for example:

YY = 2011 #year MM = 9 # month DD = 7 #day UTcor = 0 #ut offset HR = 12 #hour Min = 53 #minute Sec = 0 LONG = 0 #degrees, -ve if West +ve if East latitude = 0 #The latitude of the telescope; a scalar JD = julian_date(YY,MM,DD,HR,Min,Sec,UTcor)

You can also grab the function from: jd.py.

I'm probably going to put a php version up on the webpage for people to use too...

We went out and tried to take a colour image of M101 and the supernova.. not the best colour image I've ever made (looks like there was some dust on the telescope causing some odd image artefact that I've cleaned up a little but messed up my dynamic range):

(oh [here is the previous images])

I've finally managed to take a picture of a comet, something I've been hoping todo for a number of years but in the past have been thwarted by a number of things... anyway here we go
Comet C/2009 P1 Garrard:

The Giant Metrewave Radio Telescope (GMRT) in India is one of the worlds best radio interferometers and one of the most powerful telescopes on the planet. I've had the privellage of using it for something like 500 hours of observing. It always been fun and an interesting place to visit.

An edge on spiral galaxy taken with the Faulkes Telescope...

The on-campus [University of Birmingham Astronomical Society's] Grubb telescope. Along with a team from the Physics workshop I refurbished this wonderful telescope. I'm very proud of that and the optics form 1910 are still pretty epic.

The [Effelsberg radio telescope] is one of the largest telescopes on the Earth. It has a diameter of 100m and is fully steerable, a very impressive sight to see.

Low resolution spectra of Saturn, clearly visible on the extremities is the spectra of the rings - showing a difference to the central region which is the planet:

Messier 87 (also known as M87, Virgo A or NGC 4486) is a supergiant elliptical galaxy. It can be seen in the centre of this Bradford Robotic Telescope image (a short 120second exposure in the R band).

A very short exposure of the Moon in the U band with a 14inch telescope...

The 305m [Arecibo telescope] is the largest single dish telescope in the world. Its just awesome. I've had the prillage of using this for a project I'm part of, GALFACTS, and its an amazing sight and pretty scary up at the reciever platform.

M20 - the Trifid Nebula is an H II region located in Sagittarius - (2x30s BRV taken at Wast Hills)