My astrophotography 2021

[hhzhang]

The task of photographing a new moon is accomplished!



This is the first time I have ever photographed a new moon. Before this, the thinest (youngest) moon sucessfully taken was more than 24hrs after the new moon position, at 1.7% illumination factor.

Now, Islamic New Year 2021 began in the evening of Monday, 9 August and ends in the evening of Tuesday, 10 August.

So that's the first sight of the Islamic new year's first new moon.

Astronomically at the time of this photograph, it was past the new moon position (conjunction with Sun) by 21 hours (<24hrs) only.

So both astronomically and according to the Islamic calendar, this is truly a new moon.

I actually wished for a better weather condition -- if not for the clouds above the horizon, I might be able to capture some details of the earthshine.

I hereby wish all my Muslim friends a happy Islamic New Year!

Of course, happy National Day!

[hhzhang]

2021-Aug-11

Let me call this double-conjunction.



1)
A rare celestial event happening in the night sky: the close approach of a thin waxing crescent moon with Venus.
Yes, the crescent moon and the brightest star (actually planet). The two brightest celestial objects in the night sky.

2) On earth, in the foreground. Of course beautiful.

But I am sorry, the unfavorable weather (persistent clouds) ruined my plan and I had to settle for a lower-than-expected image quality for the moon.

Nevertheless, the beauty of heaven in conjunction with a beautiful structure on earth is definitely something fascinating, isn't it?

When will this happen again?

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Behind the photo.

This is a rare event cum an astrophotography challenge I had been anticipating for a long time. The preparation had included studying Google maps and sky maps over and over again, plus a few scouting trips to select sites with interesting foreground structures.

All was set.

Except for the weather. The sky turned much more cloudy than in the last two evenings.

I was about to give up, but decided to take chance and to wait for possible occurrences of cloud gaps in the target direction.

Alas, not even a single patch of clear sky at the moon-venus conjunction. Anyway, I took a few shots of the conjunction when the direction was relatively clear. The persistent high clouds constantly and completely obscured the faint features of the earthshine which would otherwise add a great deal to the image.

I came back not empty-handed. Plus, it is a good learning journey. And above all, I did enjoy the sighting.

[hhzhang]

2021-Aug-13

Perseid Meteor Shower peaked this morning for Sg observers.
Well, it actually became an event of shower + meteors, not a meteor shower.

Seeing the clouds dispersing after 4AM, we went out to an observation site and were welcome, not by a starry sky, but by a light shower.

We wish it would get clear soon and moved on to another observation site at Paris Ris Park. Just 10 mins drive+walk later, the sky there was clearing, much to our delight.

At the time when I was busy setting up my gear, a fireball hit the zenith area. I wished similar meteors would visit us again -- but in the next hour+, we only caught a handful of meteors plus artificial satellites.

So there are a few shots of remarkable meteors here.
A. A fireball caught by the camera. We did not notice it and only found it in the photo. It was just above the horizon. It is so bright that it cast a reflection light beam on the seawater!

B. A nice bright meteor.

C. The meteor trail was captured in two 15-sec exposures that are 1-second apart. This 1-second gap left a short missing section in the image. The meteor happened to begin in M45 the plaides cluster and end in the Hyades cluster.

[hhzhang]

I was intrigued by an article in Sky&Tel August'21 about the Pegasus I Galaxy Cluster. Here is my attempt at capturing it through a remote observatory

[hhzhang]

2021-Aug-15

First quarter moon, again.

[hhzhang]

2021-08-09 to 2021-08-16

Managed to capture the motion of Sedna, a far far away large (~1000km diameter) object in the outer solar system. With aphelion at 937AU and orbital period of 11,000 years, it is our generation to witness it traveling through perihelion at 76AU only (?!). Today it locates at 85AU from the sun and from the earth.

JPL Horizon predicts its brightness at 20.9, brighter than Gongong that I captured the other day. However, it took me a few attempts to get the work done. It seems that one should not always expect the remote telescope to produce sharpest images every time.

[hhzhang]

Far far away super galaxy cluster.

Pandora's cluster, a.k.a. Abell 2744, bears a high redshift z=0.3. One of the most distant clusters on the Abell list. Wikipedia page describes the comoving distance at 3.98Gly, more than 13x the distance of the coma super cluster.

That is the limit of reach for most amateur grade telescopes, I think. I have tried iDK20+60min exposure, and produced the final photo of the cluster as below.



Nearly every objects there is a galaxy! It is real fun identifying each of the bright spots using astronomical software (astroimagej + the simbad web service).

[hhzhang]

Here is a closeup of the image, lower to the centre of the frame.

See how each faint spot in the iDK20 image is actually a galaxy in the Hubble image.

[hhzhang]

.. a few shots from my fight against the miserable weather for astrophotography

The close approach of Mercury to Mars took place on Aug 20. Yet they only became visible through a gap between clouds just above the horizon. Poor condition for capturing any brilliant images. But anyway my hope to record this event was fulfilled.

Only in hindsight and informed by my wife who learned it on facebook, I came to realize that it can be called "水火相融“。 I'd rather call it "水火相逢“。

As Mercury and Mars are moving, relative to the sun, on the opposite direction, they will meet once again but on the other side of the sun (predawn estern sky).

[hhzhang]

Bluemoon on Aug 22-23 night. It was very cloudy all night long until 5AM, when the moon began to show its beauty through thin clouds.