Rarest Visual Neptune Observation — Archived by ALPO Astronomy (USA) & BAA Astronomy (UK)

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Rishabh Sagar avatar

🔭 Captured from the Bright Skies of New Delhi (Bortle:-9—Sky Condition)

Telescope: 130mm Newtonian Reflector

Eyepiece: Svbony 7–21mm Zoom Eyepiece

🌠 Observation Summary:

Hello Everyone, My name is Rishabh Sagar. On the night of 4th September 2025, I successfully captured Neptune, the farthest known planet in our Solar System, along with the nearby TYC 4663–378 star (magnitude ~10.8), a yellow- white star with a distance of 1,300 light years from Earth and Saturn in the same field of view.

Despite the heavy light pollution of New Delhi, the faint bluish disk of Neptune was discernible near the 10.8-magnitude star — a rare sight for small amateur telescopes. Identifying Neptune visually through a 130mm Newtonian under urban skies is both technically demanding and scientifically rewarding.

This observation was later verified by Roger Venable (ALPO Research Team, USA) and has been officially archived in the ALPO 2025–2026 Remote Planets Report, marking it as a confirmed planetary observation.

🪐 Captured & Verified Objects:

1️⃣ Neptune (Magnitude ~7.8) — Faint blue planetary disk; distant gas giant, 4.3 billion km away from Earth.

2️⃣ TYC 4663–378 (Magnitude ~10.8) — Field star used as a reference for planetary confirmation with a distance of 1,300 light-years from Earth and a yellow-white star.

3️⃣ Saturn — Brilliant yellowish planet visible in the same observing session.

📍 Observation Details:

Date: 4 September 2025.

Location: New Delhi, India. (Bortle:-9—Sky Condition)

Verification: Confirmed by Roger Venable (ALPO Research Team, USA).

Archival: ALPO Remote Planets Section — 2025–2026 Report & BAA Astronomy (UK) in Neptune Apparition Notes.

Capture Type: Single Night, Single Attempt.

💫 Rarity & Significance:

Capturing Neptune through a 130mm telescope from a heavily light-polluted city is a remarkable accomplishment. Typically, Neptune requires dark rural skies and high magnification to be visible. Detecting it alongside a 10.8 magnitude field star demonstrates precise alignment, careful star chart referencing, and optical skill.

This observation not only showcases the power of amateur astronomy but also highlights how small telescopes can contribute valuable scientific data when combined with accurate verification and reporting.

🧭 Quick Facts about Neptune:

Average Distance from Earth: ~4.3 billion km

Apparent Magnitude: ~7.8 (barely visible in small telescopes)

Angular Size: ~2.3 arcseconds

Color: Pale blue due to methane absorption in its atmosphere

Discovered by: Johann Galle, 1846 (based on Le Verrier’s calculations)

✅ Acknowledgments:

Verified & archived by ALPO Remote Planets Section (2025–2026)

Special thanks to Roger Venable for guidance and confirmation & BAA Astronomy (UK)

“Even from the heart of a bright city, the faint blue spark of Neptune reminds us — distance is no barrier when curiosity leads the way.” ✨

BAA Astronomy - Neptune Apparition Notes

📷 neptunelabel.pngneptunelabel.png📷 neptunelabels.PNGneptunelabels.PNG📷 neptuneplanet.pngneptuneplanet.png📷 labelledneptune.pnglabelledneptune.png📷 saturnandneptune.pngsaturnandneptune.png

John Hayes avatar

Rishabh Sagar · Jan 15, 2026 at 05:59 PM

This observation not only showcases the power of amateur astronomy but also highlights how small telescopes can contribute valuable scientific data when combined with accurate verification and reporting.

That is very nice but please help me to understand what scientific data came from this?

Rishabh Sagar avatar

Although no new scientific data were produced, the observation is unique because of the challenge involved in visually observing Neptune from Bortle 9 Sky conditions with a small-aperture telescope, and it serves to illustrate the beauty and discipline of classical astronomy.

Well Written