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m77, ngc55 và ngc300

Bữa trước có dịp ra Quảng Nam ở vùng bờ biển Bình Minh, Thăng Bình. Trời mùng 10 âm lịch, trăng lặn lúc nửa đêm. Có mang theo ống nhòm 20x80.
Trước khi đi thì nghĩ rằng ở đó trời tối, sau nửa đêm, trăng lặn thì bầu trời sẽ đen kịt và Ngân hà sẽ sáng tuyệt vời. Tuy nhiên, khi đến đó lúc nửa đêm thì, ngạc nhiên chưa, bầu trời sáng nhờ nhờ - cảm giác còn không đen bằng Sài gòn những đêm mùa khô trời trong. Bầu trời phía bắc còn sáng rõ quầng sáng của Đà nẵng – cách đó 60km. Hóa ra là hôm đó trời nhiều sương và bầu trời còn phủ một màn mây mỏng. Thỉnh thoảng, sao Mộc còn có quầng, do lớp mây mù đó phản chiếu ánh sáng. Tuy nhiên thì trời vẫn nhiều sao hơn hẳn ở Sài gòn.
Thất vọng, nhưng vẫn cố xem thế nào. Mục tiêu đêm nay là m74, m77, ngc247, ngc55 và ngc 300 trong đó dự kiến khó nhất sẽ là m74 (độ sáng 9.2) và ngc300 (độ sáng 9.0). Suốt cả đêm hầu như không nhìn được cái nào trong số này. Nhưng được một vài lúc trời bớt mù, mỗi lúc kéo dài khoảng 5-7 phút và trong những lúc đó thì nhìn thấy được ngc55, ngc300 và m77.
Ngc55: (trong chòm sao Sculptor, cách ngân hà dưới 10 triệu năm as) dẹt (vì chúng ta chỉ nhìn được mặt bên của nó) , và đặc biệt là có vẻ rất dài. hôm sau về check lại kích thước thì đúng là nó dài thật (dài 32’). Dài hơn đến gần 1/3 so với hàng xóm nổi tiếng hơn của nó là ngc253 đến 7’.

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28x110

Garrett Optical 28x110 on the Series 5000 tripod and video head also from Garrett. Thank Garrett for making this affordable tripod, otherwise I would have to spend as much as, if not more than, the value of the binos for the mounting. The whole setup weighs 13-14kg.

Will this be the biggest binos that I ever own? Yes, until they can make big binos from light weight materials, or until I move to the countryside to live. Big binos are lovely, and my heart and soul want to go for the biggest. But my reasoning mind says different. Logistics for big binos is daunting. They are heavy, bulky and fragile-needing too much care. You'll have to baby them too much. And, unlike a big reflector, if they get out of collimation, you'll be in trouble. Bringing a 7kg pair of binos and a 7kg tripod to dark sites is not fun, and I just can't carry more than that.

So, obtaining the 28x110 is an event to me, as this might be the biggest binos that I will ever use, although I really hope not.

Binoculars Dream Team

10x50 Fujinon Polaris FMT-SX, 20x80 Oberwerk Standard, 28x110 Garrett Optical.

With the arrival of the 28x110, the dream team has been completed. From left to right, front line, are the 10x50, 20x80, and 28x110. Note how big the 28x110 is, given that the 20x80 is already a big pair of binos, and the 10x50 is also big compared to other 10x50s. The other bino behind the three is the 15x70, which is out of action because of miscollimation and broken prism glue. It currently is used for practicing binoculars repair. However, it is a memory of the Scotland days, and my first serious investment in astro equipment. It helped me see M81/M82 - my first thrill in galaxy hunting.

Here is a summary of each pair and what they are intended for:

10x50: the Fujinon Polaris. very good optically and mechanically. This is used for quick scanning of the sky, learning the constellation, accompanying me on really rough travel, quick detection of DSOs, and (hopefully soon) viewing very big comets.

20x80: the Oberwerk Standard. It will accompany me in normal travel and be used in observing individual galaxies, large galaxy groups, and big comets.

28x110: the Garrett Optical Signature Series. the unquestioned King of the team. This is reserved for well-planned astro travel. It will be used for galaxies, galaxy groups, comets, moon and planets. Especially, I hope this binos will show me the spiral arms of M33.

Now, all I need is dark skies.

(uh, note that all the binos can be used for spotting the neighbours as well.)

Dark sites of the world

This is NASA's satellite image of the world at night (click on the image for larger image size). It shows us the distribution of lights made by human beings and the places where we can still find dark/pristine skies. Combining the criteria of dark sky, dry climate, friendly temperature, accessibility and ... fun, here is my list of my desirable places to bring our equipment to and watch the stars:

Mongolia

Xinjiang (China)

Tibet

Afghanistan/north Pakistan

Central Asia (near the Caspian sea)

The Sahara countries

Chile

Australia

Central and Central Highland of Vietnam (just because we live in this country)

New Guinea (well, the climate here is not dry at all, but it's a great great place to travel to anyway)

And, of course, on a small boat in the middle of any ocean at night.

Let's hope we soon can make this astro-travel.

Jupiter in 28x110 update

Last night, maybe the sky was better. My view of Jupiter in the 28x110 improved compared to the previous day. I could see/detect, beside the 2 equatorial bands, the 'polar caps' of Jupiter as well (color in the areas near the 2 poles). This was clearer in the pole to the left of the picture above (southern?), and detectable in the other pole. The view is clearer when I looked in one eyepiece at one time (I think that's acceptable for binoculars this big?). So, this view is comparable with my view through small telescopes at the same magnification. Good.

The photo above is an approximation of the view at the eyepieces of the 28x110, with color slightly darker on the bands (Photo: Stellarium screenshot).

Jupiter through 28x110 binoculars

This is approximately how Jupiter and moons look through my new GarrettOptical 28x110 binoculars. (Jupiter was like this, but the moons were not like this but like light points only). Two equatorial bands were clearly seen, and one band was thicker/darker than the other. I remember from earlier use of telescopes that magnifications around 30x should reveal polar caps as well, but I have not seen these with the 28x110. Maybe seeing conditions? (Photo: Stellarium screenshot).