Double Rainbow

A bright double rainbow with the dark Alexander's band between the two bows. The mainbow has also some interferencebows. The picture was taken and the border of Lago Maggiore (Italy).

Cosmic rays and sunspot numbers Solar Cycle #25

I relooked into the data to see if the current increases sunspots of solar cycle (cycle #25) has a impact on decreased cosmic rays. The data I used was :

1) Sunspot data from Royal Observatory of Belgium, Brussels (WDC-SILCO-SIDC) with
2) Galactic Cosmic Rays data from University of Oulo, Finland

The data was plotted, starting from Jan 2009 till last month June 30, 2022. The graph is still showing an inverse correlation between solar minimum/maximum and cosmic radiation min/max.

see also my previous blog on this subject : link. 

The mechanism is believed that the sun during a less active period, the sun's magnetic field will be weaker with decreasing solar wind. This solar wind acts as a shield to protect Earth against high energetic cosmic rays. During solar minimum, those high energetic cosmic rays penetrate further into Earth's atmosphere resulting in more counts/s. This is what the Neutron Monitoring System of groundstation Oulu (Finland) detects.

The sources of high energetic cosmic rays (typically 5-30GeV) are from beyond our Solar System and even from outside our own milky way and thus Galactic and Intergalactic. For that we talk about (Inter)Galactic Cosmic Rays.

Magnetic and Geographic North

When you use a magnetic compass, the needle points to the Magnetic North. This is a slightly different direction than the True Geographic North, which is along the Xaxis of our coordinate system. The angle difference between True North and Magnetic North is called magnetic Declination angle D. It is positive if the compass needle points to the east of True North, and negative if it points to the west of True North. This is a very important number to keep track of for navigation.

So what is the magnetic declination in my backyard? 

According NOAA data (see this link) the declination is about 1,999°

The magnetic Inclination angle, I, also called the Magnetic Dip angle, is a measure of how steeply a magnetic field line passes into the surface of Earth. If you were to hold a compass perfectly horizontal, it would 'point North' but its tip would also dip vertically to the ground. This feature was first discovered in 1581 by the English mariner and compass builder, Robert Norman.

So what is the magnetic inclination in my backyard? 

According NOAA data (see this link) the inclination is about 66,35°

What about Bx, By, Bz and the total magnetic intensity B? 

According NOAA data (see this link) Bx=19644nT  By=685nT  Bz= 44898nT

The total magnetic Intensity B= 49012nT

According my iPhone B=47580nT (using App Physics Toolbox Sensor Suite)

Magnetism - NASA Magnetic Math

I found a good basic description of magnetism especially as it applies to earth's magnetic field and solar activity.  Despite the fact that, next to gravity, magnetism is the most popularly-known force of nature, there are surprisingly few resources available. 

Via this link I found some good lectures included exercises : 

- NASA SpaceMath

- Magnetic Math 

8 years and 1000 Sunspots later

This week a new Sunspot with number AR3040 was observed. No big thing, but for me it was. Going back in time to april 16, 2014, I made my first picture of Sunspots. That day the Sun was covered with 9 sunspot groups (AR2032 - 2040). The picture was made using my Nikon D60 camera and Dobson OrionXT12.

8 years later and 1000 sunspots later I'm still fascinated by Sunspots. Every time when imaging a new Sunspot  my skills are increasing. On top of this I invested in my equipment and software and this resulted in much better pictures of Sunspots. I'm now imaging Sunspots in white light, CaK and H-Alpha.

Zonnekijkdag 3 juli Averbode

Op zondag 3 juli zal sterrenclub Helios-Averbode deelnemen aan de Zonnekijkdag. Vanaf 13h00 tot 17h00 zullen Helios leden hun zonnekijkers opstellen en informatie geven over onze eigenste Zon. Dit alles gaat door Het Moment van de abdij van Averbode.

Comet C/2017 K2 (Panstarrs) and IC4665 session 2

Image of session 2 with 5x90s exposure of Comet C/2017 K2 (Panstarrs) and openstar cluster IC4665 (Summer Beehive Cluster).

Setting : TLAPO80/480 f/6 with ASI2600MC
Lights 5x90s, darks, bias, flats and darkflats
Software : N.I.N.A, Stellarium, APP, CS4, DeNoise AI