My astrophotography 2021

[hhzhang]

2021-4-13

A stroll with the family in the Lower Seletar Park after dinner. The western sky was covered by high clouds, and a chance of watching a magnificent sunset eluded us. How about the moon just passed the new moon (the previous day was New Moon) at <2% illuminated? Surely it was quite low in altitude following the sun.

Searched in the cloud gaps over the western horizon for the first possible sight. Did not have much hope, but at 19:45, there it was! At just shy of 5degree altitude, its faint but definite arc came into view. It quickly moved downwards to the horizon and disappeared behind the clouds/haze soon.

Ramadan crescent moon.



This is also to wish every Muslim friend here a happy Ramadan 2021!

May the crescent-shaped moon of Ramadan 2021 brighten your path towards enlightenment! Ramadan Kareem!

[hhzhang]

2021-4-18 Learning the use of ASIAir Pro. And iOptron SmartEQ Pro got its replacement RA motor -- after two RA motors failed. The mount is a little bit lousy -- I suddenly could not get autoguiding working well on DEC. Polar alignment with ASIAir Pro is difficult in Singapore -- miss the drift align function of PHD2.

Shot a few targets with a small 70mm APO and 105mm lens. Processed the data from the APO only -- still need much work to get flat frames correct for the 105mm lens.

Only one target for the small APO. The running chicken nebula.

[hhzhang]

Revisit the bright stars in Centauris plus Proxima Centauri.

Nearest stars against the backdrop of Milky Way

[hhzhang]

Rho Ophiuchi. It was past midnight and the target had climbed to a high altitude. To my dismay, the battery pack went low and ASIAir refused to work. Ended up with only 8 exposures of 60s each.

[hhzhang]

Now it becomes interesting to compare the best eyes out there with my small refractor. Yes, Hubble in space vs a small APO from poor Singapore's conditions.

Just for fun! At the centre is the aforementioned pair of stars ~3" apart that are barely separated in my image.

Was reading a new article on Sky&Telescope here https://skyandtelescope.org/astronomy-n ... luster-m3/
Delighted to know that the subject of the artcle, the first variable star discovered in a globular cluster, V154 a.k.a. Barnard's Variable, is readily captured in my astrophoto too. Yes, it is no other than the bright bluish star in the picture.

[Airconvent]

Revisit the bright stars in Centauris plus Proxima Centauri.

Nearest stars against the backdrop of Milky Way

Now have an idea of Proxima's relative position in the triple system. Thanks for sharing!

[hhzhang]

Was considering if it is worthwhile to invest in my own remote telescope to be hosted by some dark-site observatory. High cost is almost prohibitive, but a seemly equally important question is simply "why?"

Why do I do remote imaging?
just for clear and dark sky, excellent astronomical seeing (for high-resolution imaging)?

But I have to question myself if I can commit to well-utilisation of any own remote telescope. Instead, would it just be ok to subscribe to existing online remote telescopes? I have had some experiences. Every time, I submit the request, a web form, and keep waiting a few days until the imaging is completed, and moving on to do image processing. That definitely cannot compare to the experiences of setting up the telescope in the field and fighting all the odds to get sharp and clean images while watching the stars with own eyes from time to time to feel the deep connections.

Then I discovered that the ATEO remote telescope service also provides a collection of past "Starbase" astrophotography projects. Most of these are not free to access. I paid a few dollars to download a few hours' worth of subexposures of the galaxy triplet NGC6769-71. After editing with DSS and Siril, here is the result

[hhzhang]

The target is not accessible to my small setup from Singapore. It is in the deep southern sky in the constellation of Pavo -- reaching nearly 30deg altitude maximum. At 200 million light years from earth, the galaxies are very dim and difficult to capture. Nevertheless, it is among the best examples of interacting galaxies.

Is this my astrophotography? Definitely not. But did I enjoy a little bit of excitement when processing the data to better appreciate the vista in the distant universe? Certainly yes.

Would I be more excited if these subexposures were captured after my payment to other's remote telescope service? Hmm, if the target has already been imaged hundreds of times, why do I bother to repeat? Well, some internet telescope services even go far to provide "one-click" popular-target observation function --- what's the point !!??

(In this case of NGC6769-71, it is not any popular one -- there are few quality astrophotos by amateurs.)

Surely that's not the case here. But if someone has already used the same remote telescope to shoot the same target, would you pay to shoot your own photos, creating an incremental duplicate data set? (If there is any new event like supernova eruption, it will surely be an exception).

Now, would I have more excitement if these raw subexposures were captured using my (imaginary) own remote telescope compared to using other's? I really don't know.

But one thing is certain: these days we are spoilt with different options to create astrophotos and to appreciate the beautiful universe.

[hhzhang]

An interesting side-by-side comparison between the ATEO-3 shot and what the giant 8.2m telescope of ESO sees.

[hhzhang]

2021-4-25

Clear night but under a full moon. Shot a few easy objects.

The moon



Omega Centauri, the largest globular cluster of our galaxy.

Actually a bit disappointed with the image. It is really a large size object --- but it would not be visually impressive until the super dense member stars are well resolved.