September 2006

30/09/2006
Local:Vale da Lama - Alpiarça

Vale da Lama VII

The day ended with a less than a inviting sky, but when the midnight sounded and an example of the most perfect concertation between the gravity and atmosphere, both Moon and clouds were gone. The humidity was intense, transformed to fog by 4 am.
The SQM reached 21,00 at the middle of the session.
For company I had several friends that were dedicated to do astrophotos that if can see here.


NGC 188

Open Cluster NGC 188

This galactic cluster is considered the third oldest, having a likeable 7 thousand million years (7 Ga) of age, more 2,500 that our Sun that is however probably a member of a cluster with the same age. After the quite more faint NGC 6791 in Lyra and somewhere lost at Auriga Berkeley 17. Although this cluster has many old stars, is still quite far from the youngest globular cluster (start from 13 Ga).
Mainly composed by F, G and K 10 magnitude and up stars , the study of these old clusters is important to help better date the age of our Galaxy disc.
It is located very close to the polar star, at about 4 degrees but belongs to Cepheus constellation, an it can be described visually as one faint and vague impression, without obtaining a firm form. The brightes stars start at magnitude 10.0 (and there are few) and also very esparse did not help the 90mm aperture used. The Millenium Star Atlas (MSA) cart 2 was instrumental to its detention.

A good example of a giant K0 star of magnitude 4,2 2 UMi (2 Ursae Minoris) is at the bottom of the image. This star is also a good, or flarely example, of a historical name, therefore this star does not currently belong to Ursa Minor, but yes to Cepheus, but still bears the incorrect number given by Flamsteed.

Polaris (Alpha Ursae Minoris)

Finally took a photograph of one of the most looked (but not observed) boreal sky regions by whom uses a mobile equatorial mount. That little cross marked below is the reason of many spoiled photographs and much GoTos misses.
Polaris forms with other fainter stars a triangular asterism which invariably is the first vision tougrh the telescope that I have whenever I mount the P2Z for the Sky90 or the FC60, first through the polar finder followed by the usual “startup” eyepiece, the 24mm Panoptic that magnifies 21x and with which is already possible to notice it's duplicity of the star gives the bearings above of the equator. Being the closest Cepheid variable star to the solar system, still serves to better calibrate our system of distances and when the Hubble eventually image an even closer companion star , it will be possible to determine with great precision its mass within years.

Fundamental data:

  • Magnitude V (Johnson): 1.97
  • Spectral Type : F7:Ib-IIv SB
  • Distance: 132.3 ± 8.4 parsecs (431 ± 27 light years)
  • Luminosity: 2370 ± 300 x Sun
  • Absolute magnitude : -3.64 ± 0.14
  • Other names : POLARIS; Alruccabah; Cynosura; Phoenice; Lodestar; Pole Star; Tramontana; Angel Stern; Navigatoria; Star of Arcady; Yilduz; Mismar.

Polaris

Edege-on galaxy NGC 891

Finally! This galaxy already was beginning to became a traumatical lost case of not-observation. With the precious aid of MSA (cart 101, to who comes from Almaak or cart 100 for who comes from M34), did not give space for doubts where to try to find this dodgy galaxy, its long detection was aided by moving the sight field up and down and until it appeared, very, very faint narrow impression that even using indirect vision was impossible to hold. But the galaxy orientation agreed with the cart.

Fornax dwarf galaxy

This Local Group's dwarf galaxy was being scrutinized before the intense fog fell. Cart 403 zeroed its position, but remained invisible and even started to take a photograph that only caught water vapour - the fog had arrived.

16/09/2006
Local:Atalaia (Montijo 38º44N 8º48W)

Atalaia XXVI

The SQM measure 20,25 on average with the Milky Way quite present , little humidity, pleasant temperature. The Moon rised at 02:00 and some clouds also appearing, then the night extended by more 1 or 2 hours for the most attendants.

I didn't come especially prepared to this observation, and with no goal to follow I was jumping telescope to telescope to see what the rest of guys were doing, in special an Atik Instruments protoptype that Rui Tripa and Pedro Mota were testing that seems to promise to lower the entry price in the economic-selected club of cooled 16 bits CCD cameras. Gregório was entertained detecting the loss of some photons fom a star with a exoplanet transiting.

Meanwhile, Capricornius was about to transit with Aquarius just behind (and above) and decided to give a tour by it's brighter DSOs with the Sky90.

NGC 7009 "Saturn Nebula" - Bright and notable, with the "ears" forming it's elongated shape, but yet not resolved( nagler zoom 3mm)

M73 -helps to understand the nebulous effect that some stars can cause when we use small apertures.

M72 - small and diffuse globular

M30 - a bit better than the later but with some stars detaching.

Now at Andromeda/Pegasus/Triangulum region gave the usual tour by the local Messiers (M15,M31,M32,M110,M76,M33) and NGC 7331 also.

NGC 404 - a remarkable sight of galaxy so close to a bright 2 magnitude star (Mirach).

NGC 891 - one more time impossible to get a glimpse, even using indirect imagination, that didn't surprise me because under a sky with less 1 magnitude also did fail to obtain such deed, only its observation using the 20cm. I made then some exposures of this naughty galaxy. The 3x5 minutes image shows how faint this galaxy is, with abou 13 magnitude surface brightness. As always, near was the orange/blue double star Gamma Andromedae that I believe to be more impressive than Albireo.

M74 - Very faint and round galaxy without any nuclear condensation.

To refresh the memory, I made a naked eye recognition of Fish and Whale, Aries constellations.

http://www.atalaia.org/encontro.php?id=196



07/09/2006
Local:Pátio (Leiria 39.75N 8.82W alt:60m)

Partial Lunar Eclipse

Heavy fog and clouds, but was worth to see in the binoculars on the 2 minutes truce a lunar eclipse rising, The second this year. As bonus this was “the biggest” full moon of the year distant only the 356,626 km at the photo's time .


Partial Lunar Eclipse 19:30 UT