Astronomy | Xinyu Du

Total Lunar Eclipse Phase Sequence

Mon, 08 Sep 2025 00:00:00 +0000

A phase sequence of the total lunar eclipse of September 8, 2025, recording the Moon entering Earth’s umbra.

During totality, the Moon appears copper-red because sunlight passing through Earth’s atmosphere is refracted into the shadow, with shorter wavelengths preferentially scattered away.

Total lunar eclipse phase sequence

Star Trails over Zuo Dijiang Observatory

Thu, 28 Nov 2024 00:00:00 +0000

Star trails photographed above the Zuo Dijiang Observatory at Nanjing University’s Xianlin Campus, from nearly an hour of continuous exposure.

The North Celestial Pole lies near the top of the frame; the trails record the apparent diurnal motion of the celestial sphere caused by Earth’s rotation.

Zuo Dijiang Observatory, Nanjing University

Sunspots and Zifeng Tower at Sunset

Wed, 06 Nov 2024 00:00:00 +0000

Photographed from the rooftop of the Student Activity Center at Xianlin Campus with a Nikon D850 at 200 mm. The setting solar disk is framed in line with Zifeng Tower, and several active sunspot groups are visible on the Sun’s surface.

Sunspots and the Zifeng Tower silhouette | Nikon D850 @ 200mm

Venus and the Crescent Moon

Tue, 05 Nov 2024 00:00:00 +0000

Venus and a thin waxing crescent photographed during evening blue hour. The apparent proximity is a line-of-sight alignment from the observer’s perspective, not an intersection of their orbits.

Venus and the waxing crescent moon

Comet Tsuchinshan–ATLAS (C/2023 A3)

Thu, 24 Oct 2024 00:00:00 +0000

Photographed after sunset with a Nikon D850. By the time of observation, the comet’s apparent magnitude had dropped significantly, so long exposures and curve stretching were needed to make the faint coma and tail visible.

C/2023 A3 (Tsuchinshan–ATLAS) | Nikon D850

First Light: Inaugural Star Trails at Qiandao Lake

Mon, 26 Aug 2024 00:00:00 +0000

An early star-trail photograph taken at Qiandao Lake, where low ambient light supported long exposures. The image stacks 120 exposures, showing stars tracing arcs around Polaris as Earth rotates.

Observation site, Chun’an County, Qiandao Lake | Nikon D850