Monthly Archives: April 2012

Friday and Saturday SJAA Astronomy Day

Observe The Sun Safely – Never look at the Sun without a proper filter!
Solar Programs are held 1st Sunday of every Month 2:00-4:00 PM at Houge Park  weather permitting

We held Astronomy Day Part 1 at Houge Park Friday night and wow what a great time. Sky was good, scopes were plenty and crowd was the largest I’ve seen. A crescent moon allowed for great views of the giant fault system Rima Hyginus which is connected by a groove to the rille Ariadaeus. The moon did not disappoint deep sky viewers. Many Messier objects were up, M44 and Leo, Virgo galaxy clusters were high in the sky. Of course planetary viewers got good looks at Saturn, Mars, and Venus. Venus is about at its brightest right now as it is both close to Earth with decent phase. And Mars just recently went through its retrograde.

Saturday was Part 2 – Solar Viewing at the New Public Library on the San Jose University Campus. A steady stream of people over the course of the day amounted to innumerable exclamations of “Wow, Amazing, Sick, and You Got To Check This Out…” H-alpha flares were all around the solar disk and I couldn’t tell you which ones we like most. At 9 O’clock on the solar disc were two massive prominences that resembled two gargoyles or Lions facing each other – elaborate bookends indeed! At 12 O’clock there were 3 prominent flares – one looked like a giant bonfire in a fireplace and next to it was a detached prominence that looked like a flame from a Bic lighter. Inside the solar disk there was a terrific number of sunspots and filaments (dark sinuous features that are prominences projected on solar surface). The sunspot count was likely in the 80’s with about 6 sunspot groups.

Below Malika with two Solar projection systems.


Recently she took a nice image of a 100+ sunspot day which we’ll post.


Later in the day Kevin came with his sunspot KILLER 10″ filtered scope!

End Note :  Great Astronomy Weekend!!

Side Note:  Not having visited the The San Jose Campus for a long time I was blown away by the fantastic diversity and new library – a beautiful place. Check out a book and check the place out.

Posted in Blog, Solar

Log your own Sunspot Number Part 2 of 2 Plus a graph showing Solar Max expected in early 2013

Like observing the planets in our solar system, observing the sun on a daily or weekly basis gives one an intimate knowledge on its workings and beauty. I have enjoyed watching the storm clouds on Jupiter and the Great Red Spot change over time. But watching the sunspots on the surface of our sun and their effect on space weather throughout our solar system is quite cool, dare I say scorching!!! Especially as we approach solar maximum.

By regularly counting sunspots you can determine for yourself if solar activity is increasing or decreasing and might even catch a solar flare. In Part 1 I introduced the formula for calculating your own sunspot number:

R  =  k (10g+s)

R is the sunspot number; g is the number of sunspot groups on the solar disk; s is the total number of individual spots in all the groups; and k is a variable scaling factor that accounts for observing conditions and the type of telescope used.

You don’t need to know your personal scaling factor “k” to log your own sunspot number. Just set it equal to 1. However

k = Rp/ISN

Where k is your personal scaling factor, Rp is your sunspot count (Rp = 10g+s) and ISN is International Sunspot Number as calculated by the The Solar Influences Data Analysis Center (SIDC).

At the end of everyday SIDC publishes a Provisional ISN that you can use as the ISN. It is within 5% of final value so you don’t have to wait until the end of the calendar month to get the Definitive ISN. You can get the daily Provisional ISN here along with an Estimated ISN for the upcoming day (and use estimated if provisional is not reported). This data can be e-mailed to you once a day by signing up here.

SIDC has calculated the average sunspot number for past months and came up with this nice graph showing is change over several years with a prediction of when the next solar maximum will be (early 2013).

SunspotGRAPH Click for Full Size

Don’t wait for the solar max to start observing. As you can see by this graph there are months, let alone individual days, that the sunspot number can “flare” into the 100’s. In fact flares don’t depend on a lot a sunspots to happen – one big sunspot group is enough.

Posted in Blog, Education & Reference Info, Solar

SJAA Solar Observing Program for Sunday April 1st

Observe The Sun Safely – Never look at the Sun without a proper filter!
Solar Programs are held 1st Sunday of every Month 2:00-4:00 PM at Houge Park  weather permitting

Our new Solar Program is seeing a great mix of new astronomers, solar observing regulars and families walking by to see “what’s-up”:

Click image to enlarge

Our beautiful star Sol is what’s up! Last month we had a terrific sunspot count of 70 and one decent sized prominence. Today we had a sunspot count of around 50 with huge prominences positioned at 3, 5 and 8 o’clock around the solar disk. 3 o’clock was a spectacular double loop prominence where magnetic field lines loop plasma right back to the Sun’s surface. It roughly had the shape of a weeping willow tree. At 9 o’clock we had an emission that looked like a sloop, a sailboat with a head and main sail… Or it looked like a giant nose in profile depending on who you talk too. At 5 o’clock we had  5 prominences all larger than the size of the Earth by several times. Also a classic Earth sized sunspot with a well defined penumbra was seen in the same field of view.

Click image to enlarge
(A)                                     (B)

Prominences (A) are small plasma flares. The ones we saw today were 2-3 times the size of Earth. Sunspots (B) appear dark because they are cooler relative to their surround. They usually come in pairs (two together) and are typically twice the size of Earth. The one we saw today at 5’oclock was isolated and about 1.5x bigger than Earth.

Now running side-by-side with Solar Observing is SJAA’s new Scope Tune-up Program (thanks to people like Dave Ittner). Got a scope you need help with? Bring it on by! And binoculars like the ones below can be fitted with solar filters to safely view the sun.

JoseBinosClub member Muzz checks out some giant Binoculars with Rob.

Log your own Sunspot Number (Part 2 of 2) will be posted in a couple of days. Check out the March Solar Program blog for Part 1.

Posted in Blog, Solar