The Sun is a G2V main-sequence star at magnitude -26.7, the only star close enough to study in detail. NEVER observe the Sun without proper solar filtration — unfiltered telescopes or binoculars will cause instant, permanent eye damage. Safe observation methods include dedicated solar filters (white light showing sunspots and faculae), H-alpha telescopes (revealing prominences, filaments, and flares on the chromosphere), and projection onto a white screen. Sunspots are dark regions of intense magnetic activity, typically 1,500K cooler than the 5,778K photosphere, and vary on the approximately 11-year solar cycle (Schwabe cycle). Solar Cycle 25 began in December 2019 and is expected to peak around 2025. During solar maximum, large sunspot groups are easily visible with proper filters, and coronal mass ejections can trigger auroral displays visible at mid-latitudes. Total solar eclipses — when the Moon's angular diameter (31.5 arcmin) precisely covers the Sun (32.0 arcmin) — are among the most dramatic natural phenomena. This geometric coincidence exists only because the Sun is both 400 times the Moon's diameter and 400 times farther away. Key missions include SOHO (1995, L1 point), the twin STEREO spacecraft (2006, stereo imaging), SDO (2010, high-resolution EUV monitoring), and Parker Solar Probe (2018, closest approach to a star, entering the corona).