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I've had a lovely session with my Takahashi 100mm refractor tonight. Particularly enjoyable because of the awful weather we seem to have had for the past month - a clear and reasonably dark sky for a decent period seems a real novelty ! I've observed a wide range of targets from Venus at dusk out to galaxies "far, far away". The distant gas giant Uranus, binary stars, star clusters, star formation nebulae, planetary nebulae and super nova remnants have also been visited and admired over the past few hours. I don't generally observe asteroids that often but tonight one of the largest in the asteroid belt, 4 Vesta, was conveniently positioned in Cetus near the 4th magnitude star Mu Cetus. At magnitude 7.7 4 Vesta was not easy to pick out in the 6x30 optical finder that I was using but the star hop from Mu Cetus was pretty simple so I had no difficulty identifying the star-like point of light amongst a distinct field of background stars. This is the Stellarium view of 4 Vestas position tonight: And a point of light is all that 4 Vesta appears as in the scope, even at high magnifications. While it is a giant among asteroids, 4 Vesta is a mere 550km or so in diameter and currently a bit over 300,000,000 km from Earth. Stellarium estimates its apparent diameter at .3 of an arc second. I don't know how accurate that is but my 100mm refractor was not going to show its disk, thats for sure ! Despite the modesty of its visual appearance, I was very happy to be observing this little worldlet during its 3.6 year journey around the Sun. A few years ago NASAs DAWN spacecraft visited 4 Vesa and produced some outstanding imagery such as this example showing the whole asteroid in all its scarred glory. 4 Vesta has clearly been though a lot in it's 4.6 billion year existance: Now one of my other astro-related interests is meteorites. I currently have a small collection of specimens of the main types built up over the past 12 months or so. Three of my samples are small representatives of a group of meteorites known as HEDs - an abbreviation for Howardite, Eucrite and Diogenite. These are types of achondrite meteorites so were formed through melting and recrystalisation of igneous rocks. The exciting thing about the HED group of metorites is that we are now fairly certain that they originated from the asteroid 4 Vesta !. So I thought it would be fun to include some photos of my little specimens of 4 Vesta in this report. Perhaps one day a sample return mission will bring back some material from 4 Vesta so that it can be compared with the meteoric samples that we have ? Here are some pictures of my specimens of these 3 types. The green cube is 1 cm square for scale - these are small pieces of rock ! Of these 3, only the Tatahouine Meteorite (the greenish one) was actually seen to fall. The other 2 were finds in the north african desert regions. Small fragments of that distant body that I was observing earlier though my telescope. Rather awesome
Last night (Sunday to Monday), a rare event happens. A dim star (mag 10) was occultated by the trans-neptunian asteroid - Huya. The strip where this event was visible passed near by my observatory. So 2:53 local time I was outside to take pictures of this event. It was a very nice night, with clear sky and good temerature for this time of the year. My data obtained by me is already to the profesional astronomers in La Palma, where they will obtain new information about this remote celestial body. I was not alone in this enterprise - another 10 astronomers around the country being involved in the project. I used my data to make a short film of the event with the most important part - occultation itself. The strip where this event was visible:
I didn't have much time out last night, with a early start this morning, but thought that I'd better make the effort with clear skies. With the weather in this country you never know when you'll get the opportunity to stargaze again and I hadn't been out since last Wednesday anyway. I tend to plan my next observing session on the days when it's cloudy. As a beginner I'm using Turn Left At Orion as my guide to objects to view. There's so much in that book that I'll probably be using it for ever especially as it's always a delight to return to the old favourites. Last night I was going to try to observe the globular cluster M2 and then get to the Helix and Saturn planetary nebulae but I got distracted. I managed the first part ok. M2 is rather in the middle of nowhere with regards to bright stars by which to find it, so after finding Sadalsuud in Aquarius in my finderscope I headed north, starhopping using my 25mm eyepiece and Stellarium as my comparison. My modus operandi for finding objects has grown to be that Stellarium is on my computer in the kitchen and I go into and out of the house remembering star configurations that I have seen in the eyepiece and compare them with configurations that are shown in Stellarium. I've got a good memory and it's a good mental exercise as well. In the end the gobular cluster M2 was not that hard to find but I'm going to have to revisit it when I'm a bit more relaxed to appreciate it a bit better. What was upsetting me was my neighbour's, yes you've guessed it, security light. My blood pressure was up a bit as a consequence and I couldn't enjoy the experience as I would have liked to. M2 wasn't as spectacular as the great globular cluster M13 in Hercules but was pretty impressive. I didn't really notice any distinct stars just a general quite bright haze of light. I pushed the magnification up to 166x and it still looked really good. It was at this point in proceedings that my plan went awry. I noticed in Stellarium, I had zoomed in sufficiently, that the asteroids Pallas and Eros were also in the vicinity. After observing Ceres last week it would be good to follow it up with a couple more objects in the asteroid belt. Pallas is, according to Stellarium, at magnitude 10. That's faint compared with the objects that I have been pursuing up til now and I wondered if I would be able to see it with my telescope. Starting at Saadalsuud again I made my way to the location of the asteroid Pallas via 16 and 15 Aquarii and HIP105075. A few faint stars later and I was looking through my eyepiece at the asteroid Pallas. I can see why William Herschel called these objects asteroids as Pallas appears just like a very faint star. I was observing it at 40x magnification but increasing the magnification to 100x and 166x didn't elicit any better view. It was still like a very faint star. On to Eros next. Once again starting at Sadalsuud and navigating north via 21 and 20 Aquarii and HIP105534 I came to the area of sky where Eros is supposed to be at the moment. What did I see? Nothing. It seems like a magnitude 13 object is too faint for my telescope in the light polluted skies as seen from my back garden. I tried averted vision to no avail. Only my imagination was trying to conjure up Eros. After this observing session I now have a new test to perform. How faint an object can I see from my garden? I'll have to plan this test for one of the next observing sessions when seeing conditions are good (relatively).
HI, all, I was collecting subs of NGC3628 (one of the Leo triplet) a few nights ago and I am pretty certain I have captured a couple of asteroid trails. Please see attached photo. This is just the Luminence subs, 6 off 5 minute subs, then some RGB's and back to luminence again. Middle left shows some dashes and another set bottom right, just underneath the big, shiny star. I woulld be interested in trying to identify them, so does anyone know where we can get details of known asteroids? Like a stellarium, or something, for asteroids? Thanks, in advance. Gordon.