In August I received a generous gift in the form of the book “The Story of the Universe in 100 stars”. I started reading and realized that each chapter – a star – contains an interesting story, something I did not know or forgot. And since the book is divided into 100 chapters, one chapter is the story of one star, it is a great book for 100 dailies. Here is 100 chapters in one long sentence with bold chapter name and one related link.
2025-09-05 Fr #1 Altair (Hikoboshi) and Vega (Orihime) are separated by the Milky Way (river Amagogava) in a 2600 years old Japanese love story celebrated on 7 day of the 7th month between a cowherd and weaver girl.
2025-09-06 Sa #2 Red dwarf 11.9mag 2MASS J18082002−5104378 B in binary star is 2000 ly away in southern constellation Ara and consists mostly only from Hydrogen and Helium then has low metallicity so it is almost as old as Universe 13.53 billion years.
2025-09-07 Su #3 Uranus was discovered by William Herschel on March 13 1781, but in March 66 years earlier John Flamsteed mistakenly recorded it as 34 Tauri and did not notice that it was slowly moving as a planet.
2025-09-08 Mo #4 Georg Puearbach and his student Johannes Müller (Regiomontanus) were determining the time of the Lunar eclipse on September 3 1457 by observing Alcyone in Pleiades to verify and improve star tables.
2025-09-09 Tu #5 There are about 300 stars named by IAU (International Astronomy Union), but only 6 of them are named after people: Cervantes(μ Ara), Copernicus(55 Cnc), Barnard’s star(V2500 Oph), CorCaroli(α2 CVn), Sualocin(α Del) and Rotanev(β Del).
2025-09-10 We #6 Dorrit Hoffleit in 1956 originally published edition of the Yale Bright Star Catalogue of the now 9110 stars mostly brighter than 6.5 mag which human could see by naked eye under dark skies based on Harvard Revised catalogue with the first star HR0001.
2025-09-11 Th #7 In 1984, the IRAS satellite observed an excess of infrared radiation at Vega, which must come from a dust ring, and the dust must be replenished by collisions of larger bodies, asteroids, similar to the formation of the Solar System.
2025-09-12 Fr #8 Rasalhague (arabic for searpent’s head), α Ophiuchi, is the brightest star in the constellation Ophiuchus – Serpent Bearer, which crosses the ecliptic, but that constellation is not among the twelve zodiacal constellations that are on the ecliptic, i.e. on the path of the Sun between the stars.
2025-09-13 Sa #9 TXS 0506+056 is a high-energy blazar, on the sky off the left shoulder of the Orion, from which the neutrino IceCube-170922A was detected by 5160 sensors near the South Pole on September 22, 2017.
2025-09-14 Su #10 Convection cells 0.8 AU big were observed in huge dying star π1 Gruis by Very Large Telescope interferometry in 2018, star is transitioning from red giant to planetary nebula.
2025-09-15 Mo #11 Tycho Brahe observed on November 11 1572 new star B Casiopae, now we know it was the type Ia supernova explosion of the white dwarf.
2025-09-16 Tu #12 In 1603, Johann Bayer published the sky atlas Uranometria, where each constellation had its brightest stars marked with Greek letters, and for example, in the popular constellation Southern Cross, the brightest alpha Crucis is even shortened to Acrux.
2025-09-17 We #13 In April 1994, astronomers Michel Mayor and Didier Queloz of the University of Geneva discovered the first exoplanet around the 5.5 magnitude star 51 Pegasi between the stars Markab and Sheat, now also known as Helvetios, using the radial velocity method.
2025-09-18 Th #14 Friedrich Wilhelm Bessel in 1838 for the first time measured a stellar parallax to the 5.2 magnitude star 61 Cygni as 9.25 light years close to the current value 11.4 ly.
2025-09-19 Fr #15 BPS CS 22948-0093 is a Population I star located in the outer part of the Milky Way, approximately 7,000 light-years from Earth with 3 times less lithium than expected value from the Big Bang and later supernovae and colliding neutron stars.
2025-09-20 Sa #16 Caroline Herschel (1750-1848) not only helped her famous brother, but also carefully revised all the errors in Flamsteed’s catalog, starting with the star 62 Orionis and the omitted stars in its vicinity, and at the end of her life she received a gold medal from both the Royal Astronomical Society and the Prussian Academy of Sciences.
2025-09-21 Su #17 For the past 100,000 years, our Sun has been moving through interstellar material ejected by the 15-million-year-old red giant star Antares and thousands of other similarly bright young stars from the Scorpius-Centaurus association, the nearest OB association.
2025-09-22 Mo #18 In the ancient past, people were often afraid of unpredictable comets, calling them, for example, hairy stars based on their appearance, and it was only Newton’s theory of gravity that made it possible to predict the movement of these frozen remains from the beginnings of the Solar System 4.5 billion years ago.
2025-09-23 Tu #19 American Astronomer Annie Jump Cannon and Edward Pickering published in 1912 list of stars beginning with the star HD 142 of type G0, where each star has designation type by letters from highest temperature range to lowest (derived from Balmer’s absorption lines): O > 30k°C, B > 10k°C, A >7500°C, F-G-K > 3500°C, M > 2000°C; letters A-N mean down going amount of hydrogen in spectrum.
2025-09-24 We #20 On January 1610 Galileo for the first time saw by his new telescope moons of Jupiter and later named them Sidera Medicea and only one day later saw them also German astronomer Sidera Marius, named them after characters in Greek mythology Io, Europa, Ganymede and Calisto and his names are used now.
2025-09-25 Th #21 Johann Bayer in his 16th-century catalog named stars with Greek letters and Latin constellation names, e.g. Alpha Canis Major – Sirius, John Flamsteed introduced numbers, e.g. 9 Canis Major, and later catalogs use catalog designations, for example, in the catalog of Henry Draper of Harvard (1918-1924) the star is HD 10180 and in the SIMBAD database its designations in various catalogs can be found.
2025-09-26 Fr #22 In the Pleiades, the star Teide1 was discovered in the Canary Islands in 1995, the first confirmed brown dwarf with a surface temperature of 2000°C, a mass of 50 Jupiters, and containing lithium.
2025-09-27 Sa #23 Red giant Alpha Tauri Aldebaran, in Arabic “the follower” of Pleiades, is star now running out of hydrogen and then burning helium, in the distance 65 million light years and in 2 million years will be passed by Pioneer 10, launched on March 3, 1972.
2025-09-28 Su #24 Between M48 and less than 3 degrees from Alpha Hydrae Alphard, just 7.5 light-years away, is the solitary planet WISE 0855-0714 (WISE = Wide-field Infrared Survey Explorer) with a surface temperature of 12 °C, and there are perhaps twice as many such nomadic planets as there are stars.
2025-09-29 Mo #25 The third closest star (after 4.2 ly Proxima Centauri and 6 ly Barnard’s star) is the 13.5 magnitude red dwarf Wolf 359 just 8 light-years away in the constellation Leo near 56 Leonis and almost on the ecliptic.
2025-09-30 Tu #26 Two independent groups began measuring the expansion rate of the universe in the 1990s using type Ia supernovae, they found the first such supernova, 17 mag SN 1990O, in the galaxy MCG +03-44-003 in Hercules and found that its expansion was accelerating, possibly due to dark energy, for which they were awarded the Nobel Prize in 2011.
2025-10-01 We #27 Algol (Beta Persei) is an eclipsing variable star 93 light-years away, varying in apparent magnitude from 2.1 m like 1.9m Mirfak or 2.2 Almach to 3.4 m for about 10 hours with a period of 2 days, 20 hours and 49 minutes, and 82” away has a companion star with an apparent magnitude of 10.5 m.
2025-10-02 Th #28 The Earth’s axis performs a precessional movement with a period of about 27,500 years, so the star Alpha Ursae Minoris, Polaris, the North Star is now near the North Pole, previously between 3942 and 1793 BC it was the star Alpha Draconis Thuban, in the future it will be Gamma Cephei Alderamin and later in 12 thousand years Alpha Lyrae Vega.
2025-10-03 Fr #29 On May 22, 2018, the star TZC 278-748-1 was eclipsed by the 88 km asteroid Penelope, and from brightness measurements at a sampling rate of 300 Hz by the VERITAS telescopes in Arizona, the size of the star was determined to be 2173 times the size of the Sun, i.e. a diameter of 3 billion km or 20 AU, so that Saturn would orbit on the surface.
2025-10-04 Sa #30 SS Leporis or 17 Leporis by Flamsteed designation is a double-lined spectroscopic symbiotic binary star system, which magnitude varies between 4.82 and 5.06, is 910 ly away and consists of A1 star and larger M6 red giant, which transfers mass by strong stellar wind to the hotter type A1 component.
2025-10-05 Su #31 In 800 ly distant Perseus molecular cloud, which spans 6×2 degrees, centered roughly on the star Atik, and has a mass of 10,000 suns, was in 2010 discovered the “first hydrostatic core” of future protostar L1448-IRS2E which has already magnetic field but luminosity only 1/10 of Sun.
2025-10-06 Mo #32 Mass extinctions could be caused by asteroid impacts triggered by the passage of a companion component of the Sun called Nemesis on an elongated orbit, which could orbit with a period of 26 million years, then according to Kepler’s third law it would have a semi-major axis of 87,764 AU and, for example, Jupiter would have a magnitude of +38.6 at such a distance.
2025-10-07 Tu #33 NAVI is the unofficial name for gamma Cassiopeiae, the middle star in the large double W asterism with a brightness of 2.5 mag and a distance of 550 light years, created as a joke by the second American astronaut Gus Grissom and is a reverse of his middle name IVAN.
2025-10-08 We #34 14 Herculis is a star of magnitude 6.6, 58 light-years away, with a proper motion of 0.3 arcseconds per year and a metallicity, i.e., the content of elements heavier than hydrogen and helium, three times greater than that of the Sun, so it has enough material to build exoplanets.
2025-10-09 Tu #35 Near Alpha Capricorni, an optical double star of α1 Cap and α2 Cap Algedi separated by 0.11°, is the radiant of the Alpha Capricornids meteor shower, active from approximately July 7 to August 15, whose parent body is the active asteroid 2002 EX12, now known as comet 169P/NEAT with an orbital period of 4 years, and this shower could be more very active after 2220.
2025-10-10 Fr #36 Anwar al Farkadian, Arabic for “the brighter of the two calves,” is the star Eta Ursae Minoris, magnitude +4.95, which can be used to test vision and darkness, similar to 5.15 mag Pherkad Minor (11 Ursae Minoris) near 3.05 mag Pherkad.
2025-10-11 Sa #37 Sirius B is the first white dwarf discovered next to the brightest star in the sky, Sirius A, and is the final stage of a star’s evolution after it has exhausted its hydrogen and helium reserves, with a high density and size comparable to a planet.
2025-10-12 Su #38 Iota Carinae, named Aspidiske and with a brightness of 2.2 magnitude, was the first bright star imaged by the Hubble Space Telescope, launched in 1990, however, the telescope turned out to be out of focus, but after repairs it is still operational.
2025-10-13 Mo #39 The distance to the Sun was first determined relatively accurately during the transit of Venus across the Sun in 1761, and in 2012 the IAU set the astronomical unit, formerly the average Earth-Sun distance, at 149,597,870,700 meters.
2025-10-14 Tu #40 By measuring the occultations of stars by asteroids, it is possible to determine their size, and in the case of measurements from multiple locations, even their shape and an example of such a measurement is the occultation of the star Nomad1 0856-0015072 by the dwarf planet Eris on November 6, 2010.
2025-10-15 We #41 A black dwarf is a cooled white dwarf, but since cooling occurs slowly and lasts longer than the current age of the universe, it will take a long time before it appears, for example, in Z Chamaeleontis.
2025-10-16 Th #42 HD 162826 is a 6.55 magnitude star at a distance of 110 ly in the constellation Hercules, which has almost the same characteristics as the Sun and is possibly its sibling.
2025-10-17 Fr #43 40 Cancri is a binary star located about 614 light-years away in the Beehive cluster (M44) with a primary component of a normal A1-type star, but with excessive luminosity and is therefore considered an extremely blue straggler that has somehow acquired additional mass from another star. Errata: On the first line should be … in the Cancer constellation,
2025-10-18 Sa #44 Elements heavier than iron are formed towards the end of a star’s life by neutron flux, either through a slow process of fussion around core layers or through a rapid process called supernova, which can be studied, for example, in the 5.38 magnitude star 171 Puppis A.
2025-10-19 Su #45 French astronomer abbé Nicolas-Louis de Lacaille(1713-1762) introduced 14 new constellations in the southern sky celebrating the Age of Enlightenment with scientific instruments and tools such as the Vacuum Pump-Antlia, the Engraver-Caelum, the Compass-Circinus, the Furnace-Fornax, the Clock-Horologium, the Mensa-Mensa, the Microscope-Microscopium, the Ruler-Norma, the Octant-Octans, the Painter-Pictor, the Compass-Pyxis, the Grid-Reticulum, the Sculptor-Sculptor, and the Telescope-Telescopium, albeit in inconspicuous parts of the sky, as demonstrated by the relatively faint 4.25 magnitude star Alpha Antliae.
2025-10-20 Mo #46 W75N(B)-VLA2 is a massive protostar located in the Cygnus X region some 4,200 light-years from Earth, about 8 times more massive and 300 times brighter than the Sun, observed in 1996 and 2014 by the Karl G. Jansky Very Large Array (VLA) radiotelescope.
2025-10-21 Tu #47 The 9.94 magnitude star HIP 13044 2300 ly away in the constellation Fornax formed outside the Milky Way and is part of the Helmi stellar stream that has circled the Milky Way several times, and was once a separate system captured by the Milky Way.
2025-10-22 We #48 The orbits of the stars of the quintuple star system KIC 4150611 in the constellation Cygnus are in the same plane, and this plane passes through the Earth, so we can observe their mutual occultations and subsequent changes in the brightness of the entire system.
2025-10-23 Th #49 Delta Cephei is a variable star that pulsates with a period of 5.366249 days, changing brightness from 3.48 mag to 4.37 mag and it is a representative of Cepheids, whose study in the Small Magellanic Cloud led Henrietta Swan Leavitt to notice that brighter stars have a longer period, which can be used to determine distances in the universe.
2025-10-24 Fr #50 The star of Bethlehem described in the Gospel of St. Matthew has in my opinion primarily a symbolic meaning, intended to emphasize the significance of the birth of Jesus, and the search for an astronomical meaning is secondary and most likely doomed to failure.
2025-10-25 Sa #51 Arcturus α Boötis is a red giant in the northern constellation Boötes (Herdsman), 36.7 light-years away with a magnitude of -0.05, it is the fourth brightest star after Sirius, Canopus and α Centauri, it is approaching us with a radial velocity of −5.19 km/s and has a high proper motion in the sky of about 2.3 arc seconds per year, or 122 km/s, so it will move south by the size of a full moon in 800 years.
2025-10-26 Su #52 In 1728, the priest and third Astronomer Royal James Bradley (1692-1762) discovered the aberration of light resulting from the relative motion of the Earth while observing Gamma Draconis, γ Draconis, Eltanin, the brightest star in the constellation Draco with a magnitude of 2.2 and a distance of 154.3 light years, which executes an annual aberration ellipse with a semi-axis of about 20 arc seconds.
2025-10-27 Mo #53 The star Merak, β Ursae Majoris, with a magnitude of +2.37, is part of a moving star cluster along with most of the bright stars of the Big Dipper at a distance of about 80 light-years and an age of about 300 million years, and together with the star Dubhe forms an asterism – a pointer to the North Pole.
2025-10-28 Tu #54 GS0416200054 is one of many pointer stars for the Hubble Deep Field in Ursa Major about 5 degrees above the star Megrez, and better choice of pointer stars in the future could yield further scientific results.
2025-10-29 We #55 The PSR B1919+21 is a rapidly rotating neutron star, the remnant of a supernova about 0.9 degree near the magnitude 4.72 star 1 Vulpeculae, the first pulsar with a period of 1.3373 seconds and a pulse width of 40 miliseconds discovered in 1967 by Jocelyn Bell Burnell.
2025-10-30 Th #56 Canopus is the second brightest star quite far from the ecliptic, even with a negative magnitude of -0.62, while the concept of stars from first to sixth magnitude comes from the Babylonians and was mathematically defined in 1850 by the British astronomer Norman Pogson so that stars five magnitudes higher are 100 times fainter and then one magnitude higher is approximatelly 2.512 times fainter.
2025-10-31 Fr #57 Eta Carinae, η Car, is a good example of the variability of the universe, being a star system containing at least two stars with a combined luminosity greater than five million times that of the Sun, located about 7,500 light-years away, formerly of magnitude 4, brightened in 1837, becoming brighter than Rigel, marking the beginning of its so-called “Great Eruption”, between March 11 and 14, 1843, it became the second brightest star in the sky, before fading far below the naked eye after 1856.
2025-11-01 Sa #58 Alphecca, α CrB, is a white star 75 ly away type A0 used by astronomers Harold Johnson and William Morgan as one of the zero points of the UBV photometric system (Ultraviolet 364nm, Blue 442nm, Visual-yellow 540nm).
2025-11-02 Su #59 Barnard’s Star is the fourth closest star, 5.9 light-years away, and in 10,000 years it will approach a distance of 3.75 light-years, it is a red dwarf with a brightness of 9.5 magnitudes near 66 Ophiuchi and has the largest proper motion in the sky, 10.3 arc seconds per year and 17 arc minutes per century.
2025-11-03 Mo #60 In her dissertation at Harvard in 1925, British astronomer Cecilia Payne-Gaposhkin described the majority composition of stars as hydrogen and helium with small amounts of other elements, mainly by studying absorption lines, which are very abundant in the star Deneb in Cygnus.
2025-11-04 Tu #61 The star Beta Pictoris in the constellation of the Painter is not far from the bright star Canopus, it is only 20 million years old, in 1983 a disk was detected around it and in 2004 an exoplanet was imaged in this disk for the first time in history.
2025-11-05 We #62 The star 72 Tauri is close to the ecliptic and on May 29, 1919, it was located near the eclipsed Sun and was one of the stars for which British astronomer Arthur Eddington measured a shift in space-time distortions, confirming Einstein’s theory.
2025-11-06 Th #63 In 1923, Edwin Hubble noticed a Cepheid star in a photograph of the Andromeda Nebula, which he designated V1, and used it to measure the distance, thus discovering that it was not a nebula, but a distant Galaxy in Andromeda.
2025-11-07 Fr #64 Kepler-1 is the name of a star TrES 2 (Transatlantic Exoplanet Survay) that already had a known exoplanet and was used to calibrate the Kepler Space Telescope at the start of its work in April 2009, which for several years continuously observed the brightness of about 150 thousand stars in Cygnus, ending in 2018.
2025-11-08 Sa #65 The exoplanet around 8.2 magnitude star HD 209458 in Pegasus is sometimes called Osiris, in astronomical parlance it is a hot Jupiter type, it was formed farthest from the star, but is now 7 million kilometers from its star, i.e. only 4 diameters of the parent star, it is evaporating, losing mass and dragging a tail behind it.
2025-11-09 Su #66 Proxima Centauri is a red dwarf (10.43 – 11.11 mag) with a tenth of the mass of the Sun, 7 times smaller and 100 thousand times fainter, it travels through space in the same direction as Alpha Centauri, 2.2 degrees apart, but 0.1 ly closer at a distance of only 4.2 ly, so the British astronomer Robert Innes named it Proxima in 1915 and in 2016 not only was a super-Earth exoplanet discovered around it but it was also found to orbit Alpha Centauri with a period of 600 thousand years.
2025-11-10 Mo #67 We observe the sky at the bottom of a rippling ocean of air, so for the adaptive optics of the telescope, NGS – “natural guide star” was first used, which should be bright enough and in a suitable place for use, and since the 1980s, artificial stars, laser-stimulated emission of the sodium layer 90 km high, have been used, first for military applications and later for civilian ones.
2025-11-11 Tu #68 The galaxy Messier 87 8.4mag in the constellation Virgo contains a supermassive black hole with a mass of 6.5 billion Suns, first imaged by the Event Horizon Telescope, a global radio telescope, on April 10, 1987, and is designated with the star M87*, or the Hawaiian name Powehi, similar to the source at the center of the Milky Way, Sagittarius A*.
2025-11-12 We #69 The roundest known star KIC 11145123 13.12 mag, 3910 ly away in Cygnus, has more than twice the diameter of the Sun, about 3 million km, but is only 3 km larger at the equator, while the Sun is 10 km larger, which can be determined by astroseismology, long-term monitoring of small changes in brightness that reflect the wobble or ringing of the entire star.
2025-11-13 Th #70 The Morning Star is a bright celestial body visible in the morning before sunrise, and is usually the planet Venus, less often Jupiter, the position of Venus in the sky repeats itself five times every 8 years, the so-called five-petalled rose of Venus.
2025-11-14 Fr #71 In July 2003, two teams observed the same star with a planet 2.5 times the mass of Jupiter OGLE 2003-BLG-235/MOA 2003-BLG-53 17.4 magnitude in Sagittarius (18h05m16.36s, -28°53’42.0”), the Polish team OGLE (Optical Gravitational Lensing Experiment) and the Japanese-New Zealand MOA (Microlensing Observations in Astrophysics), in both cases rare Planetary Microlensing Event during 23 days brightness increased 1.95 times.
2025-11-15 Sa #72 Orion Source I (05h 35m 14.5098s,−05°22′30.4820″) is a massive young star surrounded by a dusty disk, where astronomers have detected “salt” in the form of table salt sodium chloride (NaCl) and potassium chloride (KCl) using the Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope.
2025-11-16 Su #73 The word lich is an Old English word for corpse, in this case it is the 2300 ly distant pulsar PSR B1257+12 in Virgo (13h00m03.1075s,+12°40′ 55.155″), around which three planets were discovered in 1990 by the Arecibo radio telescope, in fact the first extrasolar planets.
2025-11-17 Mo #74 The Sun orbits the center of the Milky Way, which contains a black hole with a mass of 4 million Suns, in about 220 million years, but the star S0-102 is so close to the center and therefore the black hole that it orbits once every 12 years.
2025-11-18 Tu #75 The GRB 010119 is the source of a very short gamma-ray burst of 200 milliseconds that occurred on January 19, 2001, but no afterglow was observed, so one theoretical explanation could be Planck’s star according to loop quantum gravity theory exists within a black hole’s event horizon.
2025-11-19 We #76 In 2013, Ralf Dieter Scholz noticed a star in the constellation Monoceros, the red dwarf WISE J072003.20-084651.2, which 70 thousand years ago approached the Sun at 0.8 ly, or about 1/5 the distance to Proxima Centauri, and is now known as Scholz’s star.
2025-11-20 Th #77 The most distant star ever observed in constelation Leo (11h49m35.59s, 22°23′47.4″) was named Icarus and was observed through gravitational lensing by galaxy cluster MACS J1149+2223 when during observing microlensing happened which allowed to observe Icarus, a blue giant with lifespan of milions years.
2025-11-21 Fr #78 The ancient Egyptians observed the heliacal rising of Sirius, the brightest star in the sky in Canis Major, which used to occur before the Nile floods around July 19, but has shifted due to the precession of the ecliptic and now occurs in mid-August depending on the observer’s latitude.
2025-11-22 Sa #79 5.8 magnitude variable star V1364 Cygni, along with many other Cepheids, was recently used in 2018 to measure the distance and speed from the center of the Milky Way, showing that there is probably dark matter in our Galaxy as well, otherwise stars far from the center would have to move more slowly.
2025-11-23 Su #80 The Kepler satellite discovered the star KIC 8462852 in Cygnus, and in 2015, doctoral student Tabby Boyajian detected irregular brightness fluctuations, possibly caused by an irregular disk, rather than the attractive Dyson sphere under construction for journalists.
2025-11-24 Mo #81 Thanks to looters, a 4,000-year-old Bronze Age Nebra sky disc with a diameter of 32 cm was found in Germany, west of Leipzig, in 1999, the oldest known representation of the sky, which may have served as a calendar, with golden arches, the Sun, the Moon and stars including the Pleiades, with research on star 23 proving that it is not a forgery.
2025-11-25 Tu #82 Supernova SN 2008ha in the UGC 12682 galaxy in the constellation Pegasus was co-discovered by 14-year-old Caroline Moore, the youngest citizen scientist to discover a supernova.
2025-11-26 We #83 In the 2nd century BC, the Greek astronomer Hipparchus measured a different position of the star Spica than his predecessors had recorded, which he correctly interpreted as indicating that the Earth’s axis was undergoing precession.
2025-11-27 Th #84 Felis is the Latin name for the constellation of the Cat, which was created in 1799 by the French astronomer Lalande, but was not added to the other 42 official animal constellations by the IAU in 1928, however, the star HD 85951 (HR 3923) in the constellation Hydra was given the name Felis in 2018, with a magnitude of 4.92, the brightest star in the now-obsolete constellation Felis.
2025-11-28 Fr #85 WASP-12b is an extrasolar hot Jupiter planet orbiting 11.5 magnitude star WASP-12 in Auriga, discovered in 2008 by the British-led WASP (Wide Angle Search for Planets) survey, where water vapor was detected in the atmosphere by Hubble in 2013.
2025-11-29 Sa #86 ULAS J1342+0928 was in 2017 the most distant known quasar (quasi-stellar object), detected by WISE, and contains a supermassive black hole with a redshift of z = 7.54, galaxies within it are only 690 million years old after Big Bang (13.1 billion years ago), and is located in the constellation of the Boötes.
2025-11-30 Su #87 The star Sanduleak -69 202 was catalogued in 1970 by a Romanian-born astronomer in the Large Magellanic Cloud and exploded as a supernova in 1987, with three ground-based detectors able to detect neutrinos, and now only expanding rings are visible from the original star.
2025-12-01 Mo #88 About 2 degrees northeast of the star Epsilon Cassiopeiae is the pulsar 3C 58, it was speculated that it is the remnant of the supernova of August 6, 1181 recorded by Chinese and Japanese astronomers, but it is probably not, it is definitely a neutron star and if it had a higher mass, it could be a quark star.
2025-12-02 Tu #89 The French satellite CoRoT (Convection, Rotation and planetary Transits) discovered in 2009 the then first super-Earth CoRoT-7b, which orbits with a period of 20 hours, is 1.7 times larger and 5 times more massive than Earth, around 520 ly distant 11.7 magnitude star CoRoT-7 in the constellation Unicorn (Monoceros).
2025-12-03 We #90 Cygnus X 1 is one of the most powerful X-ray sources discovered by a sounding rocket in 1964, a binary system 7000 ly away separated by 0.2 AU consisting of a black hole and a blue giant with an accretion disk fed by a stellar wind, and is located in the sky not far from Eta Cygni, 138 ly away.
2025-12-04 Th #91 Although the Sun emits most in the green part of the spectrum around 500 nm, corresponding to the radiation of a black body at a temperature of about 6000 °C, it also emits all other colors, additive mixing occurs, and so we perceive the Sun as a white star, not a green star.
2025-12-05 Fr #92 The star of 9.6 magnitude Gliese 710 in the constellation of Serpens is 62 ly away, but is approaching us at a speed of 15 km/s, so in 1.35 million years it will be only 0.2 ly away from us and may cause many comets and asteroids.
2025-12-06 Sa #93 Anyone who looked at the constellation Boötes on March 19, 2008 at 6:12 UTC, for example in Europe Boötes was above the western horizon, could see for about half a minute between the stars Gamma and Eps Boo the most distant, even visible to the naked eye, gamma-ray burst GRB 080319B 7.5 billion light years away, probably a hypernova.
2025-12-07 Su #94 Gravitational waves were first observed on September 14, 2015 by the LIGO detectors in the USA and Virgo in Italy during the merger of two black holes GW150914.
2025-12-08 Mo #95 In the Large Magellanic Cloud, 180,000 ly away, inside the Tarantula Nebula, the most massive and brightest known star, R136a1, is 265 times more massive than the Sun and 10 times brighter with a surface temperature of 40,000 C, it formed 1 million years ago and has already lost 35 suns to the stellar wind.
2025-12-09 Tu #96 Trappist-1 is an ultra-cold (2290 °C) red dwarf slightly larger than Jupiter with a magnitude of 18.8 and 41 ly away in the constellation Aquarius, orbited by two Earth-sized exoplanets.
2025-12-10 We #97 The star P Cygni (34 Cygni) is visible near the center of the Northern Cross, Gamma Cygni Sadr, has a magnitude of 4.82, 5300 ly away, and is therefore one of the most distant stars visible to the naked eye.
2025-12-11 Th #98 In 2005, a star SDSS J090745.0+024507 19.84 mag, 230, 000 ly away was found in Ophiuchus, only 350 million years old, which is moving away less than 100 milion years from the center of the Milky Way at a speed of 709 km/s, hence the name OUTCAST and it is not clear whether it acquired such a speed from a black hole, during a collision of galaxies, or otherwise.
2025-12-12 Fr #99 American astronomer William Morgan, in a lecture on Boxing Day, December 26 1951, the day after Christmas, first presented the structure of the Milky Way, created by measuring the distances of young bright blue stars of type O and B, such as S Monocerotis near the Christmas Tree star cluster.
2025-12-13 Sa #100 The star Zeta Opchiuchi was ejected from a binary system a million years ago by a supernova II explosion, the cosmic rays of which may have affected Earth’s weather by producing charged particles and condensation nuclei in the atmosphere, but that does not excuse humanity from being responsible for Earth’s weather today.
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