Department of Posts, under the Ministry of Communications, has issued a commemorative postal stamp marking 125 years (quasquicentennial) of the Kodaikanal Solar Observatory (KoSO) – a landmark institution in India’s solar astrophysics research.
Key Highlights
- Occasion: 125th Anniversary of Kodaikanal Solar Observatory (established on 1 April 1899)
- Event Duration: The quasquicentennial celebration began on 1 April 2024
- Stamp Features:
- Historic Kodaikanal Observatory building with its two domes
- 6-inch telescope (installed 1850 in Madras; moved in 1900 to KoSO by Michie Smith)
- 8-inch telescope (installed 1866 in Madras; shifted to KoSO in 1930, now used for outreach)
- H-alpha image of the Sun taken on 6 May 2024
- Indian Institute of Astrophysics (IIA) logo
- Inset of ‘Butterfly Diagram’—solar latitude vs. year plot of sunspots (1904–2020 data)
- Availability: The stamp will be sold at Philately Bureaus across Karnataka
About Kodaikanal Solar Observatory (KoSO)
| Attribute | Details |
| Established | 1 April 1899 |
| Location | Kodaikanal, Palani Hills, Tamil Nadu |
| Owned & Operated by | Indian Institute of Astrophysics (IIA) |
| Initial Purpose | Solar Physics Observatory approved in 1893; foundation stone laid by Lord Wenlock in 1895 |
| Systematic Observations Began | 14 March 1901 |
| Reason for Location | Clear skies, high altitude, dust-free atmosphere – identified by Charles Michie Smith |
Instruments & Research Focus
- Initial Focus: Sunspots, solar radiation, prominences
- Modern Instruments:
- H-alpha Telescope
- White Light Active Region Monitor (WARM)
- Data Archive: Continuous solar data from 1904 to 2020 used in long-term solar activity analysis
Historical Importance
- Trigger: The Great Drought of 1875–1877 prompted the need for solar studies due to its climatic impacts
- Geographical Relevance: India’s central location and clear skies made it ideal for solar observation
Scientific Contributions
- Evershed Effect Discovery: KoSO detected the radial gas flow from sunspots (1909)
- Research Areas Expanded To:
- Cosmic rays
- Radio astronomy
- Ionospheric and stellar physics
About Indian Institute of Astrophysics (IIA)
| Details | Information |
| Established | 1971 |
| Headquarters | Bengaluru, Karnataka |
| Type | Autonomous research institution |
| Affiliation | Department of Science and Technology (DST), Government of India |
| Role | National centre for advanced research in astronomy and astrophysics |