42,772 articles
HD 204827
HD 204827 is a heavily reddened, multiple O-type star in Cepheus whose 2008 spectrum survey cataloged 380 diffuse interstellar bands, making it a standard reference sightline for that field.
HD 206267
HD 206267 is a massive multiple star system at the center of the nebula IC 1396 in Cepheus, ionizing the Elephant's Trunk Nebula from about 2,400 light-years away.
HD 214419
HD 214419, also cataloged as CQ Cephei and WR 155, is a Wolf-Rayet binary star in Cepheus whose WN6 star orbits an O companion every 1.64 days.
HD 216598
HD 216598, also known as SW Lacertae (SW Lac), is a short-period eclipsing binary in Lacerta, a W UMa contact system with a G5 V spectrum.
HD 224085
HD 224085, better known as II Pegasi (II Peg), is a chromospherically active RS CVn spectroscopic binary in Pegasus whose K2 IV subgiant is covered by large cool starspots.
HD 22468
HD 22468, also known as HR 1099 or V711 Tauri, is a bright RS Canum Venaticorum variable, a spectroscopic binary star in Taurus known for starspots.
HD 22879
HD 22879 is a metal-poor F9V dwarf star in the constellation Cetus, about 6.7 magnitudes bright, serving as a Gaia FGK benchmark star for calibrating stellar parameters and abundances.
HD 25329
HD 25329 (also LHS 21, GJ 158) is a metal-poor K-type main-sequence subdwarf about 60 light years away in Perseus, one of the best-studied nitrogen-rich halo dwarfs.
HD 284149 A
HD 284149 A is a young F8 star about 118 parsecs away in Taurus, primary of a triple system with a 0.16-solar-mass red dwarf and the 26-Jupiter-mass brown dwarf HD 284149 b at 431 AU.
HD 76151
HD 76151, also Gliese 327 or HIP 43726, is a G-type main-sequence star about 55 light years from the Sun in Hydra, widely used as a solar analog.
HD 76932
Catalogued as HIP 44075 and HR 3578, HD 76932 is a mildly metal-poor G-type star recognized as a high proper motion benchmark for thick-disc stellar composition.
HD 84937
HD 84937 is a bright, very metal-poor turnoff star in the solar neighborhood, with about 1/200 the Sun's iron, serving as a benchmark star for abundance analyses.
HD 88230
HD 88230, also known as Groombridge 1618, is a nearby K-type main-sequence star about 15.9 light-years away in Ursa Major, known for its measured diameter and cold, faint debris disc.
HD 92740
HD 92740, also cataloged as WR 22, is a Wolf-Rayet binary star in the Carina Nebula about 2.7 kiloparsecs away, one of the brightest Wolf-Rayet stars in the sky.
HD 93162
HD 93162, cataloged as WR 25, is a very massive Wolf-Rayet star in the Carina Nebula, the primary of an eccentric 208-day colliding-wind binary and a bright X-ray source.
HD 93521
HD 93521 is a rapidly rotating O-type star about 1 kiloparsec above the Galactic disk, a long-standing puzzle whose origin is thought to be a stellar merger.
HD 94028
HD 94028 is a metal-poor, high proper motion star in the Galactic halo whose supersolar arsenic-to-germanium ratio cannot be reproduced by standard s- and r-process nucleosynthesis alone.
HD 95735
HD 95735, better known as Lalande 21185, is a red dwarf star in Ursa Major about 8.3 light-years away, the fourth closest main-sequence star system.
HD 96548
HD 96548, also cataloged as WR 40 and V385 Carinae, is a WN8h Wolf–Rayet star in Carina, the brightest of its class, surrounded by nebula RCW 58.
HD 98800
HD 98800, also cataloged as TWA 4 and TV Crateris, is a young quadruple system of four K-type stars in Crater hosting the first known polar protoplanetary disk.
HD1
HD1 is a proposed high-redshift galaxy candidate at z = 13.27, identified in 2022, which would place it about 330 million years after the Big Bang.
HDE 226868
HDE 226868 is a ninth-magnitude blue supergiant star in the constellation Cygnus, orbiting a black hole every 5.6 days as the visible counterpart of the X-ray source Cygnus X-1.
HDF-S
HDF-S, or Hubble Deep Field South, is a ten-day Hubble Space Telescope observation in 1998 of a small sky patch in the constellation Tucana, revealing thousands of distant galaxies.
Headphones
Headphones are electroacoustic transducer devices worn on or in the ears that convert electrical audio signals into sound, delivering audio privately to a single listener.
Headspace gas chromatography
Headspace gas chromatography (HS-GC) is a gas chromatography sample introduction technique that analyzes vapors above liquid or solid samples, used for blood alcohol determination and residual solvents.
Health affairs
Health Affairs is a monthly peer-reviewed health policy journal founded in 1981 by Project HOPE's William B. Walsh with editor John K. Iglehart; since late 2025 published by Health Affairs Publishing, LLC, with companion journal Health Affairs Scholar.
Health and Retirement Study
The Health and Retirement Study, run by the University of Michigan since 1992, surveys about 20,000 Americans over age 50 every two years on health, work, income, and wealth.
Health effects from noise
Health effects from noise are the adverse physical and mental health outcomes caused by environmental and workplace noise, including sleep disturbance, cardiovascular disease, cognitive impairment in children, and hearing loss.
Health effects of climate change
The health effects of climate change include heat deaths, shifting infectious disease, degraded air, and food insecurity, with the WHO projecting 250,000 extra deaths yearly by the 2030s.
Health geography
Health geography, also called medical geography, is a subdiscipline of human geography studying how place, location, and spatial relations shape disease, well-being, and health care.