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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.

Advanced Search Examples (click to copy):

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

844 results found.

  1. MAXI GRB200205.29: Global MASTER-Net observations report
  2. LIGO/Virgo S200129m: Coverage and upper limits from MAXI/GSC observations
  3. LIGO/Virgo S200128d: No counterpart candidates in KAIT observations
  4. LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations
  5. LIGO/Virgo S200114f: Upper Limits from Wide-Field Infrared Search with Palomar Gattini-IR
  6. LIGO/Virgo S200115j: Coverage and upper limits from MAXI/GSC observations
  7. LIGO/Virgo S200114f: Coverage and upper limits from MAXI/GSC observations
  8. LIGO/Virgo S200112r: Coverage and upper limits from MAXI/GSC observations
  9. LIGO/Virgo S200105ae: Coverage and upper limits from MAXI/GSC observations
  10. GRB 200105A: MAXI/GSC detection
  11. LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
  12. LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
  13. LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
  14. LIGO/Virgo S191213g: Coverage and upper limits from MAXI/GSC observations
  15. LIGO/Virgo S191205ah: Coverage and upper limits from MAXI/GSC observations
  16. LIGO/Virgo S191204r: Coverage and upper limits from MAXI/GSC observations
  17. LIGO/Virgo S191129u: Coverage and upper limits from MAXI/GSC observations
  18. LIGO/Virgo S191110af: Coverage and upper limits from MAXI/GSC observations
  19. LIGO/Virgo S191109d: Coverage and upper limits from MAXI/GSC observations
  20. LIGO/Virgo S191105e: Coverage and upper limits from MAXI/GSC observations
  21. LIGO/Virgo S190930s: No counterpart candidates in KAIT observations
  22. LIGO/Virgo S190930t: Coverage and upper limits from MAXI/GSC observations
  23. LIGO/Virgo S190930s: Coverage and upper limits from MAXI/GSC observations
  24. LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
  25. LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations
  26. LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
  27. LIGO/Virgo S190910d and S190910h: No counterpart candidates in KAIT observations
  28. LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations
  29. Swift Trigger 924641 is an outburst from MAXI J1807+132
  30. LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations
  31. GRB 190823A: Swift-XRT afterglow detection
  32. LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
  33. LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
  34. LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
  35. GRB 190828A: Swift-XRT observations
  36. LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
  37. GRB 190828A: Tiled Swift observations
  38. LIGO/Virgo S190828l: Coverage and upper limits from MAXI/GSC observations
  39. LIGO/Virgo S190828j: Coverage and upper limits from MAXI/GSC observations
  40. GRB 190828A: MAXI/GSC detection
  41. GRB 190823A: Swift-XRT observations
  42. GRB 190823A: Tiled Swift observations
  43. GRB 190823A: MAXI/GSC detection
  44. Fermi GBM-190816: Coverage and upper limits from MAXI/GSC observations
  45. LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
  46. LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan
  47. LIGO/Virgo S190814bv: No counterpart candidates in KAIT observations
  48. LIGO/Virgo S190814bv: Coverage and upper limits from MAXI/GSC observations
  49. IPN triangulation of GRB 190805B
  50. LIGO/Virgo S190808ae: Coverage and upper limits from MAXI/GSC observations
  51. GRB 190805B: AstroSat CZTI detection
  52. GRB 190804B: Swift-XRT afterglow detection
  53. Konus-Wind observation of GRB 190805B
  54. GRB 190805B: Swift-XRT observations
  55. GRB 190805B: Fermi GBM detection
  56. GRB 190805B: Tiled Swift observations
  57. GRB 190804B: Swift-XRT observations
  58. GRB 190805B: MAXI/GSC detection
  59. MAXI GRB190804.33 Global MASTER-Net observations report
  60. GRB 190804B: Tiled Swift observations
  61. GRB 190804B: MAXI/GSC detection
  62. LIGO/Virgo S190728q: No counterpart candidates in KAIT observations
  63. LIGO/Virgo S190728q: Coverage and upper limits from MAXI/GSC observations
  64. LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
  65. LIGO/Virgo S190727h: Coverage and upper limits from MAXI/GSC observations
  66. LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
  67. LIGO/Virgo S190720a: Coverage and upper limits from MAXI/GSC observations
  68. LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
  69. LIGO/Virgo S190718y: Coverage and upper limits from MAXI/GSC observations
  70. GRB 190714A: an X-ray flare from 2E 1624.6+1504/UCAC4 525-061488
  71. GRB 190708B: confirmation of the X-ray afterglow
  72. GRB 190714A: Tiled Swift observations
  73. GRB 190714A: MAXI/GSC detection
  74. GRB 190708B: Swift-XRT observations
  75. Konus-Wind observation of GRB 190708B
  76. GRB 190708B: Tiled Swift observations
  77. MAXI GRB190708.83 Global MASTER-Net observations report
  78. GRB 190708B: MAXI/GSC detection
  79. LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
  80. LIGO/Virgo S190707q: Coverage and upper limits from MAXI/GSC observations
  81. LIGO/Virgo S190706ai: Coverage and upper limits from MAXI/GSC observations
  82. GRB 190706A: MAXI/GSC detection
  83. LIGO/Virgo S190630ag: No counterpart candidates in KAIT observation
  84. LIGO/Virgo S190701ah: Coverage and upper limits from MAXI/GSC observations
  85. GRB 190701A: MAXI/GSC detection
  86. LIGO/Virgo S190630ag: Coverage and upper limits from MAXI/GSC observations
  87. LIGO/Virgo S190602aq: Coverage and upper limits from MAXI/GSC observations
  88. LIGO/Virgo S190521r: Coverage and upper limits from MAXI/GSC observations
  89. IGO/Virgo S190521g: Coverage and upper limits from MAXI/GSC observations
  90. LIGO/Virgo S190519bj: MAXI/GSC Observations
  91. LIGO/Virgo S190517h: MAXI/GSC Observations
  92. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
  93. LIGO/Virgo S190513bm: MAXI/GSC Observations
  94. LIGO/Virgo S190512at: MAXI/GSC Observations
  95. LIGO/Virgo S190510g: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  96. LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
  97. LIGO/Virgo S190510g: Potential host galaxies on the updated skymap from the GLADE catalog
  98. LIGO/Virgo S190510g: MAXI/GSC Observations
  99. LIGO/Virgo S190510g: Potential host galaxies from the GLADE catalog
  100. IceCube-190504A: MASTER optical monitoring analysis

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