C/2007 N3
February 23, 2009
Chronicle
night observation and astrophotography.
We arrived
Crow, Toledo, wanted to look outside the southwest of Madrid as an alternative to Puerto Star and The Inviernas for those nights that we should limit the clouds watching these areas. We
at 18 hours, before sunset, for to mount with light. Commented on the way that the place was beautiful, vast fields that were lost in the distance, wavy, and the Toledo Mountains as a backdrop. Toledo past we Argés, we continued to thumb and then to Crow, marked with a cross. It is a town of 1,571 inhabitants and 37.51 km2. To the south and there is no population, just a bit west to Peña looming Sales Aguilera. This time we stayed near Crow, too, some lamps of people bothered a bit. But for the next time will try to move a little further east along the road to Sonseca and we will stay in chestnut yes that is a lost place in the world and LC.
begin to prepare the team as it fell in the afternoon and took some pictures of the horizon (here you can see a 360 º, the horizon is full):
coordinates with GPS:
North 39 º 38 ' 55 "
West 4 º 11' 46"
Height: 771 meters on sea level.
A detail of the evening, as we walked the road to approach the area of \u200b\u200ba curious bird observation forced us to stop, very brave stood in the middle of the road as if to welcome us. Great Spotted Cuckoo was a European. I took a picture. It seems that these cuckoos only breed in the Iberian peninsula, it is increasingly common to see them in the past winter months are ahead of the spring ... announcing it somehow. This seemed to warn us of a great adventure ...
began the adventure of the night, After a sunny weekend but the wind could not miss a Monday more stable. We set up camp light, and when dusk came and we had everything ready.
at 19h 11 'local time we were 9.4 º C with 52% humidity and a dew point of 0 º.
rode Vixen binoculars 12 x 80 to try to find the comet C/2007 N3 Lulin, even he had to leave because he was between Virgo and Leo, specifically near Saturn, and this was about to poke through the horizon. The sky is still had this beautiful blue tint of twilight. Venus shining in the western horizon, high, bright. Setting in parallel form, took the opportunity to take a look at the beautiful planet with a 12mm eyepiece. The telescope has a focal short so I did not look great but if clear, leaving me with my mouth open, like a thin slice of tangerine, and a crescent like the one in the flag of Turkey but with open horns . With binoculars also appreciated it and could see perfectly your position on the sun, like a gondola on water.
When the night prepared Sky Quality Meter-L (SQM-L) to take measurements. At 20:30 local time this "outer eye" was a measurement of magnitudes 20.91 arc seconds square.
While waiting for the comet began to come up with photographs. Every day I like working with this team, in tune with the steps and the ease with which potential problems are solved makes me excited thinking about productive nights.
But let the photo for another hour and begin telling the visual experience of the comet.
OBSERVATION OF COMET Lulin
Local Time: 22:03
Team: Vixen 12x80 binoculars
Eye Sidereal: 21.03 mag / arcsec ^ 2
I started looking for the comet, did not know exactly their position but I knew that tonight would be close to Saturn. So I pointed to the area between Leo and Virgo, I started to sweep step, the area was near the horizon yet and I thought maybe if he had bad vision would show the same horizontal dim. Not so. In fact was not in the area where he was wanted, I came up a little south of Leo and suddenly appeared on the field ... a large cotton field clearly visible. I stopped abruptly. Separated in the eyes of binoculars and looked at the sky ... Yoho I was looking in the wrong area. Saturn was very close, so close that both objects entered in the same field of the binoculars. I could not believe what a sight so fantastic. At first glance had not been able to locate, he was still very low, but now he knew where he was. They came in abundance in the field, and as comparison is the Belt of Orion and found that Alnitak, Alnilam and Mintaka field occupied almost entirely with this could get an idea of \u200b\u200bhow far would the comet with the naked eye when it was higher , for the separation of these three stars are a perfect indicator. As reference field of the binoculars is 4.2 º.
the first picture I placed the comet's position with respect to background stars seen through binoculars.
first thing that stands out is the decimal, rounded, very prominent, large displays and impossible to confuse and indirect vision could be differentiated shades of silver. The core was not as punctual as a star, a mass was appreciated powerful light and dense, but fine, but stood out very well.
comet tail started soft and inviting to the east, denser as we look into the coma, delicate transparent and the more we move away from the nucleus.
Comet was still low on the horizon and hard to see the length of the tail, seemed to overcome once the diameter of the coma, but that, rightly thought, was due to its low height and not yet optimal conditions of the night (the "Eye" showed an improvement after a while).
The round mass was the most prominent, and with averted vision could play a challenging walk the dust tail. The position of the nucleus took it as closely as possible, being at this point about halfway between the star 80 Leonis and HIP55574 (a little closer to the latter). HIP55574 forms a triangle with HIP55467 and HIP55460 and will serve as reference for the movement later.
binoculars Moving scrolled down to the comet that appeared in the field, the planet Saturn. Focusing on the whole I found that they were separated just over 2 degrees. Saturn showed splendid as only he knows, but with the peculiarity that could barely see the rings, so planes were barely visible a thin golden line across the planet. Titan stood near Saturn's disk at one end, the Like others of its weaker satellite. The position of the Rings (as flat) at this time makes even see them cross in front of the planet Jupiter as it happens.
at 23:13 local time I went to look out the binoculars. Caramba and runs the Comet: departs from 80 Leonis and goes to the star HIP55574 ... going head-to-be with her.
At 00:29 local time was again glued to the binoculars. The image left me surprised, the movement was evident not only because practically had hidden the star HIP55574 and had passed literally. Now that star peeped through the transparent tail of the comet. The nucleus was located right between HIP55574 and HIP55467. But what surprised me most was that the queue had increased its length. I left and I was thinking, now is clearly much longer than before, before I could have played a trick on the position of 80 Leonis that being in the middle of the faint tail and be bright and somehow I "turn off" weakest part of it that "maybe" stretched below ... hmm - "the same thing I tried hard enough" - ... I decided to look again.
Si ... clearly now the tail is stretched over and in failing to bright stars in the middle I could see it in all its length, with averted vision I could see their fuzzy boundaries beyond 80 Leonis. This is the second drawing. It is obvious that the best quality of the sky at this time was to increase the image detail, and also helped its height above the horizon.
I went back to release the brakes of the binoculars and I went back to witness the magnificent conjunction of Saturn and the comet. The Lord of the Rings came on the scene ... superb! Now if that is spectacular. The delicate gold ring tearing the world stood on the top left corner, could be seen as a thin line marked with a box cutter while the train of satellites orbiting him closely. And the beautiful comet, vaporous, like a lady wrapped in fine silver gauze. Across the sky seems to call attention to the powerful planet. What all so beautiful! So delicate! All adorned with a multitude of stars of different brightness ... is a feast for the senses.
tried to look at first glance, and suddenly the sky seemed darker in that area ... - "is it not also to be somewhat higher sky better? "- I got the" Eye "and pointed to the zenith lens ... read 21.17 gave
-" Oysters how to note and how it detects the pileup this " -.
were at 19h to 9.4 º C but now at 00:29 pm the temperature had dropped eight degrees, we were at 1.4 ° C and a humidity of 92%.
Despite the low temperature and humidity sky quality had improved greatly, you could tell it darker and added to the height he had won the comet was a splendid sight as a result comes from his solar system.
looked at first glance to the region of Saturn, down, indirectly, the state, with the sticks much better prepared than a few hours before ... and the result was not long in coming. Indirectly easily looked foggy area, like a pale cloud and rounded the area southwest of Saturn over Tau Leonis.
Through binoculars I watched as the comet exceeded HIP55467 also can see more clearly the very long tail that was up to 80 Leonis.
It was almost 2 am, especially at 01:50 h the "Eye" marked a measure of 21.19. The Heaven had improved a bit more if it were not for reaching 100% humidity at night would have been exceptional.
One of the things that struck me the night was dark and clean it was the southern horizon. I looked at the stars in that area, to the region of Canis Major and the Popa and gave me the impression that he saw many more stars than usual, usually the sky near the horizon is smudged with dirt from the atmosphere difficult to see details. But tonight the horizon was exceptional, very bright stars could see practically glued to the ground. And that made me curious: if, how beautiful is the horizon dotted with stars seem sharp as diamonds. Let's see ... I will point your binoculars, because these details of the region are not poop every day.
front of me, to the south, were the Montes de Toledo, but they were far away and barely rose in height, so the horizon was lost just three or four degrees. We were
39 ° 38 'north , that meant a theoretical horizon of up to -51 º 30'sur. I could find with the naked eye bright stars of the constellation Vela according to the map indicating a latitude of -47. Specifically Al Suhail (Delta) and Suhail to Muhlif (gamma) of the Vela precisely the two stars that frame the remnant of the Vela supernova , among many other fainter stars (plus some clusters).
If we were tonight in the middle of spring, in this same position they are now the stars could admire the famous cluster Omega Centauri. Soon we will see again. .
Finally, the photographic results of the night was a success and the goals we set were achieved.
's great how well the team works and what joy is when you see all the equipment and software work perfectly. Tonight we brought two cameras Canon 350D, a modified and one unmodified. We take the comet to take pictures with both and see the differences.
In the photo above taken with the camera without a filter we see the red part of spectrum is much more intense compared with the bottom picture in which even have a color balance is much more balanced limited information by cutting the spectrum before the 650 nm. I'm not talking about H-alpha, just that charges of the phenomenon of Rayleigh scattering in the tail of dust (particle size) and detects more than that redness. This phenomenon coupled with the balance is not cleared and stained more red than usual could be causing the color of the dust tail. A normal camera just accused this phenomenon and shows the comet in its colors everyday.
As it was already 2:10 am and had more than an hour's drive to return home with great sadness we decided to end the session, not only because of the time but because the moisture and cold, we had covered ice pack, the team and ourselves.
We were exhausted from the cold but satisfied, only the visual part met expectations but I was lucky to have been enjoying an imaging session made the night unforgettable.
We knew we had to go back but as they say we were skulking and we do not do to start ... until the voice of conscience brought us to the harsh reality. - "... Tomorrow is a business!" - . When the clouds
confine us in our homes for months and the need to press one can not be limited to the few opportunities that provide weekend ... and Monday ... even if you have to leave .... DATA
From observations
02/23/1909 23:29 TU. (In local time and 00:29 of the day were 24)
12 x 80 Binoculars 4.2 °
Country Heaven clear, moonless, very stable. Quality
sky as SQM-L: 21.17 mag / arcsin ^ 2
He was in the zone south of Leo, Virgo and the sextant from near Saturn. Specifically
about 2 º 14 'south of Saturn and Sigma Leonis.
On the horizon rose a height of about 45 degrees.
A glance showed diffuse and pale, like spot rounded gray cotton. The estimation of the brightness at 23h UT realized using 12x80 binoculars. Used as comparison stars Tau Leonis (mag 4.9) and 80 Leonis (mag 6.3) obtaining a magnitude of 5.3. (Bobrovnikoff method).
(In a subsequent remark, Feb. 26, at the same time was seen with the naked eye a lot easier, better than 23, stood next to Rho Leonis easily as a round nebula. Locate it did not cost anything. estimate did not shine that night).
Saturn and the comet came largely in the visual field of the binoculars, (these are 4.2 ° and the separation of the two was slightly more than 2 °) quite a sight to behold.
The approximate position of the comet was: 11h 22m 00s, 4 º 8 ' 00.
Coma round about 22' arc, rising in brightness toward the center.
Degree condensation, DC: 6. (The kernel is defined but does not become prime).
Cola perfectly visible to binoculars, oriented east-southeast.
anticol
visible but very weak with averted vision, oriented west- northwest.
The main queue oriented east-southeast:
very prominent, with a length of 1 arc (AP 110 º).
oriented west-northwest anticol:
very weak, 10 'arc approximately (AP 290 º).
For photography cameras use two nearly identical: a Canon 350D modified without the IR blocking filter and another without changing its original state.
was placed in both chambers IDAS-LPS filter.
The first shots of the night were made with the modified and unmodified with the latest. They are easy to distinguish by color because they are made with the modified go redder and the other with its distinctive green color.
At 22:21 UT the comet is a 5 ' HIP55574 star with position angle with respect to it than 150 º (AP). I superimposed a map of the Millennium for AP measurements accurately tail, corresponds to page 752.
Taking three images and emphasizing only the comet's nucleus with layers you can see the shift that has taken with respect to the stars. We see three minutes and it appears to trace (Far left), with five minutes is very long and with only 10 seconds without moving.
At 22:37 UT the comet is a 2 '40 "star HIP55574 with a position angle with respect to it of 200.3 º (AP).'s Closest approach.
At 22:43 UT the comet is a 3 '00 "star HIP55574 with a position angle with respect to it of 230.9 º (AP).
Substitute as amended by the camera and did not modify the second batch of photos of the Comet (shown in green color).
So almost two hours later, at 00:32 h UT, the position had changed dramatically.
He was 24 '40 "star HIP55574 with a position angle with respect to it of 286.1 º (AP). Now HIP55467 is closer and has exceeded, at the time the photo was separated from it 3 ' AP arc of 327 º. The closest he has gone from HIP55467 is 1' 45 "arc an AP of 16.4 º.
For comparison here I put two identical images taken with both cameras, with the same exposure and ISO, the results are very different especially in color. The time at TU.
Ana Leonor Hernandez
