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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"

32485 results found.

  1. GRB 240828B: SVOM/C-GFT optical upper limit
  2. GRB 240828B: SAO RAS optical upper limit
  3. GRB 240828B: KAIT optical upper limit
  4. GRB 240828A: SAO RAS optical observations
  5. GRB 240828A: Fermi GBM Observation
  6. GRB 240629A: First GRB Detected by BurstCube
  7. GRB 240828A: KAIT Optical Afterglow Candidate
  8. GRB 240825A: SVOM/VT optical detection
  9. GRB 240825A: further SAO RAS optical observations
  10. GRB 240825A: iTelescope optical observations
  11. GRB 240828A: Fermi-LAT detection
  12. GRB 240828A: Tiled Swift observations
  13. GRB 240828A: AstroSat CZTI detection of a long burst
  14. GRB 240825A: Upper limits from a neutrino search with IceCube
  15. GRB 240819A as a likely X-Ray Flash
  16. GRB 240828B: Swift ToO observations
  17. GRB 240821A: PRIME near-infrared observations
  18. GRB 240825A: VLA detection
  19. Fermi GRB 240828A: Global MASTER-Net observations report
  20. SVOM GRB 240821A: optical afterglow discovery
  21. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  22. GRB 240825A: GECAM detection
  23. GRB 240825A: ALMA detection
  24. GRB 240825A: SAO RAS optical observations
  25. GRB 240824A: GIT optical upper limit
  26. GRB 240819A: Swift afterglow confirmation
  27. GRB 240825A: TNG optical photometry and spectroscopy
  28. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  29. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  30. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  31. GRB 240825A: GMG Continued Optical Observation on the Second Night
  32. GRB 240824B: Ondrejov D50 optical limit
  33. GRB 240825A: KAIT optical observations
  34. GRB 240825A: PRIME near-infrared detection
  35. Konus-Wind detection of GRB 240825A (bright/long)
  36. GRB 240825A: Fermi GBM Observation
  37. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  38. GRB 240825A: AKO Optical Follow-Up Observations
  39. GRB 240825A: AstroSat CZTI detection of the long bright burst
  40. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  41. GRB 240825A: Swift/UVOT Detection
  42. GRB 240825A: REM detection of the optical/NIR afterglow
  43. GRB 240825A: VLT/X-shooter redshift
  44. GRB 240825A: SVOM/C-GFT optical observations
  45. GRB 240825A: Montarrenti Observatory optical observations
  46. GRB 240825A: MASTER optical counterpart observation
  47. GRB 240825A: Fermi-LAT detection
  48. GRB 240825A: LCO optical observations
  49. GRB 240824B: KAIT optical upper limit
  50. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  51. GRB 240824B: Fermi GBM Observation
  52. Fermi GRB 240825A: Global MASTER-Net observations report
  53. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  54. GRB 240824B: NOT optical upper limit
  55. GRB 240825A: GMG Optical Observation
  56. Swift GRB 240825A: Global MASTER-Net observations report
  57. GRB 240825A: 1.6m Mephisto multi-band detection
  58. GRB 240825A: AKO Optical Afterglow Detection
  59. GRB 240825A: Skynet Optical Afterglow observations
  60. GRB 240825A: Nanshan/HMT optical afterglow observations
  61. GRB 240824A: Swift-BAT refined analysis
  62. GRB 240824A: SVOM/C-GFT optical upper limit
  63. GRB 240824B: Swift-XRT afterglow detection
  64. LIGO/Virgo/KAGRA S240825ar: Identification of a GW compact binary merger candidate
  65. GRB 240824B: Swift/BAT arcminute localization of a burst
  66. GRB 240824B: Swift ToO observations
  67. Fermi GRB 240824C: Global MASTER-Net observations report
  68. GRB 240824A: Swift/UVOT Upper Limits
  69. GRB 240821A: Swift/UVOT observations of the XRT sources.
  70. GRB 240824B: MAXI/GSC detection
  71. GRB 240824A: Retraction of GCN 37255
  72. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  73. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  74. GRB 240824A: KAIT optical upper limit
  75. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  76. GRB 240821A: Colibri Optical Upper Limit
  77. EP240820a: PRIME J-band Observations
  78. GRB 240821A: Swift-XRT observations
  79. GRB 240821A: REM optical/NIR upper limits
  80. GRB 240821A: LCO optical observations
  81. GRB 240821A: JinShan optical upper limits
  82. GRB 240809A: Mondy and AbAO Optical Observations
  83. GRB 240821A: SVOM/VT follow-up and optical upper limit
  84. GRB 240821A: GMG Optical Upper Limit
  85. Fermi GRB 240821A: Global MASTER-Net observations report
  86. GECAM-B observation of a short burst from SGR 1E 1841-045 / Kes 73
  87. GRB 240821A: Fermi GBM Observation
  88. GRB 240821A: Swift ToO observations
  89. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  90. GRB240821A: EIRSAT-1 GMOD Detection
  91. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  92. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  93. Fermi GRB 240821B: Global MASTER-Net observations report
  94. EP240801a: Keck/LRIS spectroscopic redshift confirmation
  95. GRB 240821A: SVOM/GRM observation
  96. GRB 240821A: SVOM/GRM observation
  97. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  98. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  99. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  100. GRB 240819A: Swift-XRT observations

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