UPDATE: Since writing this article, BT have moved off the Yahoo platform (see: www.bt.com/newemail) – I’m unsure if the same issue is apparent for BT users, but the same issue exists for Yahoo as far as I know.
If you are a BT or Yahoo email user, then you may notice occasionally that your email takes an age to arrive. Sometimes you may even discover that an email someone sent you you has never arrived. If you experience this, here’s a bit of an explanation as to why this may be happening…
Continue reading BT/Yahoo? Slow Email?
Continuing in the migration of my old site, here’s a post with a round up of my best h-alpha solar images. For a while, I owned a Coronado Solarmax 60 with BF15 blocking filter which I used to use on my Takahashi FC60NZ – I traded this more recently for the FLT110 – I found that I really wasn’t getting to use the h-alpha equipment for most of the year (work gets in the way when the sun is up!).
The h-alpha filter works by using an etalon to restrict the wavelengths of light as viewed through the telescope down to only a small region of the spectrum around 656.3nm (typically with a bandwidth of <0.7Å), which is a principal emission wavelength of excited hydrogen atoms (for the transition n=3 to n=2 in the Balmer series). This allows features such as prominences, flares, filaments and active regions to be observed, whereas in white light these are often not as noticable or are invisible.
Continue reading Solar H-Alpha Imaging Round Up
So the weekend just gone has had fabulous weather here in the UK – sunny, warm (for February!) days, and cold clear nights – and so I thought I’d try to setup my imaging kit to have a go at some astronomy for the first time since April 2007, and also as a bit of a dry run before the Kelling Heath star party in April. I even managed an image of the moon – 30 images using the ST2000XM on the FLT110, processed in Registax – click the image above to view it!
Of course, nothing goes smoothly:
Continue reading Equipment Woes and a Crescent Moon
RA: 11h 19m, Dec: 13°15′ (approx. centre)
The famous Leo Triplet is a small group of three spiral galaxies (namely, M65 (NGC3623 – bottom-left), M66 (NGC3627 – top-left) and NGC3628 (right)) that is located about 35 million light years away between Theta and Iota Leonis. All three galaxies are readily visible in a small telescope, though NGC3628 tends to be the hardest of the three to spot. Additionally, the smaller galaxy NGC 3593 (not shown) may also be a member of this group.
This image was taken from the dark skies of Mid-Wales on December 21st, 2006 as a “quickie” before sunrise after a run on imaging the Cone Nebula (to follow in a later post) – it’s only about an hour of total exposure. A much longer imaging run would allow the faint surrounds of M66 and the “tidal tail” of NGC3628 to be brought out, but unfortunately, as is so often the case with imaging in the UK, the clouds came in for the next 5 nights leaving the telescope ready to go, but unable to actually take an image…
Image centred at: RA: 09h 55m 34.7s, Dec: +69°19′ 52″
Up is 89 degrees E of N
(Plate solve from nova.astrometry.net)
M81 and M82 in Ursa Major are two of the brightest members of the M81 group of galaxies. M81 (often called Bode’s Nebula after being discovered by Johann Elert Bode in 1774) is a large bright spiral approximately 12 million light-years distant, whilst M82 (the “Cigar Galaxy”) is an irregular starburst galaxy, highly disturbed by gravitational interaction with other members of the group.
This was taken from Kelling Heath at the 2007 Spring Star Party on an excellent night after we had been fogged out for the previous two nights! I’m hoping to go again this year to do some more imaging…
In the region of M81 and M82 (and across large parts of the northern sky), there is a large faint nebular complex associated with dust and gas expelled from the plane of the galaxy. The region here is part of MW3 (Mandel-Wilson Catalog of Unexplored Nebulae) and the faint dusty areas show up faintly in a strongly stretched image of the region. This has been refered to as an “Integrated Flux Nebula” since it reflects the galaxy’s light rather than that of a single star. Also visible is Holmberg IX (below M81) which is a small, faint blue irregular galaxy also in the M81 Group.