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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

3363 results found.

  1. Fermi trigger No 713974668: Global MASTER-Net observations report
  2. Swift GRB230818.98: Global MASTER-Net observations report
  3. IPN triangulation of GRB 230815B
  4. GRB 230812B: continued SAO RAS optical observation
  5. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  6. Fermi trigger No 713205976: Global MASTER-Net observations report
  7. Fermi GRB 230807A: Global MASTER-Net observations report
  8. Fermi trigger No 713134237: Global MASTER-Net observations report
  9. Fermi trigger No 712927418: Global MASTER-Net observations report
  10. Fermi trigger No 712798043: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S230802aq: Coverage and upper limits from MAXI/GSC observations
  12. LIGO/Virgo/KAGRA S230802aq: Identification of a GW compact binary merger candidate
  13. LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
  14. GRB 230723B: Swift-BAT refined analysis
  15. IceCube-230727A: Upper limits from a search for additional neutrino events in IceCube
  16. IceCube-230724A: Upper limits from a search for additional neutrino events in IceCube
  17. IceCube Alert 230725.90: Global MASTER-Net observations report
  18. IceCube Alert 230724.08: Global MASTER-Net observations report
  19. Fermi trigger No 711805358: Global MASTER-Net observations report
  20. Swift GRB 230723B: Global MASTER-Net observations report
  21. Fermi GRB 230723A: Global MASTER-Net observations report
  22. IceCube-230707A : MAXI upper limit and NICER follow-up observation of Swift J1753.5-0127
  23. IceCube-230707A: No candidates from the Zwicky Transient Facility
  24. LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
  25. Fermi trigger No 710117592: Global MASTER-Net observations report
  26. Konus-Wind detection of GRB 220623A
  27. Fermi GRB 230628C: Global MASTER-Net observations report
  28. Fermi GRB 230628D: Global MASTER-Net observations report
  29. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  30. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  31. GRB 230623A: Swift-XRT observations
  32. GRB 230623A: Tiled Swift observations
  33. MAXI GRB 230623A: MASTER optical observations
  34. GRB 230623A: Tiled Swift observations
  35. GRB 230623A: MAXI/GSC detection
  36. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  37. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  38. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  39. IPN triangulation of GRB 230616A (short)
  40. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  41. LIGO/Virgo S230620al: Global MASTER-Net observations report
  42. LIGO/Virgo S230618s: Global MASTER-Net observations report
  43. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  44. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  45. LIGO/Virgo S230617ba: Global MASTER-Net observations report
  46. LIGO/Virgo S230618k: Global MASTER-Net observations report
  47. LIGO/Virgo S230618d: Global MASTER-Net observations report
  48. LIGO/Virgo S230617bc: Global MASTER-Net observations report
  49. LIGO/Virgo S230617aq: Global MASTER-Net observations report
  50. LIGO/Virgo S230617aj: Global MASTER-Net observations report
  51. LIGO/Virgo S230616s: Global MASTER-Net observations report
  52. LIGO/Virgo S230608as: Global MASTER-Net observations report
  53. LIGO/Virgo S230609a: Global MASTER-Net observations report
  54. LIGO/Virgo S230608ah: Global MASTER-Net observations report
  55. LIGO/Virgo S230529ay: Global MASTER-Net observations report
  56. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  57. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  58. LIGO/Virgo S230525a: Global MASTER-Net observations report
  59. LIGO/Virgo/KAGRA S230518h: Updated Sky localization
  60. IceCube Alert 230524.47: Global MASTER-Net observations report
  61. Fermi trigger No 706610076: Global MASTER-Net observations report
  62. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230523A
  63. LIGO/Virgo S230522a: Global MASTER-Net observations report
  64. LIGO/Virgo S230520ae: Global MASTER-Net observations report
  65. GRB 230520A: CALET Gamma-Ray Burst Monitor detection
  66. LIGO/Virgo/KAGRA S230520ae: Upper limits from IceCube neutrino search
  67. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  68. GRB 230520A: MAXI/GSC detection
  69. LIGO/Virgo/KAGRA S230518h: Coverage and upper limits from MAXI/GSC observations
  70. LIGO/Virgo S230518h: Global MASTER-Net observations report
  71. LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  72. GRB 230510B: Fermi GBM detection
  73. GRB 230510B: AstroSat CZTI detection
  74. GRB 230510B: CALET Gamma-Ray Burst Monitor detection
  75. GRB 230510B: MAXI/GSC detection
  76. GRB 230506C: TSHAO possible afterglow candidate
  77. GRB 230420A: Swift-BAT refined analysis
  78. GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
  79. GRB 230409B: Mondy optical upper limit
  80. Fermi trigger No 702745263: Global MASTER-Net observations report
  81. MAXI GRB230408.82: Global MASTER-Net observations report
  82. GRB 230409B: Swift detection of a burst
  83. Fermi trigger No 701883729: Global MASTER-Net observations report
  84. GRB 230328B: Swift-BAT refined analysis
  85. GRB 230328B: Nanshan/NEXT optical upper limit
  86. Fermi GRB 230328A: Global MASTER-Net observations report
  87. Fermi trigger No 701321709: Global MASTER-Net observations report
  88. Konus-Wind detection of GRB 230309A
  89. GRB 230322A: Fermi GBM Final Real-time Localization
  90. Fermi GRB 230313A: Global MASTER-Net observations report
  91. GRB 230307A: soft X-ray detection with LEIA
  92. Further improved IPN localization for GRB 230307A
  93. GRB 230307A: MAXI/GSC upper limit
  94. Fermi GRB 230308A: Global MASTER-Net observations report
  95. Fermi trigger No 699294715: Global MASTER-Net observations report
  96. Fermi trigger No 699311646: Global MASTER-Net observations report
  97. GRB 230220A: Correction to GCN 33352
  98. Fermi GRB 230220B: Global MASTER-Net observations report
  99. GRB 230220A: MAXI/GSC detection
  100. IceCube-230217A: BOOTES-4/MET Optical Observations

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