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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"

32482 results found.

  1. GRB 260428A: TERI Gamma-ray detection
  2. Konus-Wind detection of GRB 260519C
  3. GRB 260509A: SVOM/ECLAIRs refined analysis
  4. GRB 260519C: NuSTAR detection of prompt emission
  5. Konus-Wind detection of GRB 260518A
  6. GRB 260516D: SVOM/ECLAIRs refined analysis
  7. GRB 260515A: SVOM/ECLAIRs refined analysis
  8. GRB 260421B: radio detection with the VLA
  9. GRID detection of GRB 260511A
  10. GRB 260509A: CrAO ZTSh optical upper limit (Duplicate Submission)
  11. GRB 260509A: CrAO ZTSh optical upper limit
  12. GRB 260516D: EP-FXT follow-up observation
  13. GRB 260516D: GOTO optical counterpart detection
  14. GRB 260516D: LCO optical observations
  15. GRB 260515A: further Liverpool Telescope observations
  16. GRB 260516D: SVOM/COLIBRÍ (FM-GFT) optical observations
  17. GRB 260516D: GTC/OSIRIS+ spectroscopic redshift z = 1.801
  18. GRB 260516D: GROWTH-India Telescope optical detection
  19. GRB 260516D: SVOM/VT optical bright candidate
  20. GRB 260515A: CrAO ZTSh BVRI optical observations
  21. Fermi GRB 260516C: Global MASTER-Net observations report
  22. Konus-Wind detection of GRB 260515A
  23. GRB 260515A: Liverpool Telescope optical detection
  24. GRB 260515A: LCO optical counterpart detection
  25. GRB 260515A: SVOM/COLIBRÍ (FM-GFT) optical observations
  26. GRB 260515A: EP-FXT follow-up observation
  27. EP260514a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  28. EP260514a: NOT optical counterpart confirmation
  29. EP260514a: TRT optical counterpart candidate
  30. EP260514a: SVOM/VT optical candidate
  31. Fermi GRB 260516B: Global MASTER-Net observations report
  32. GRB 260515A: SVOM/VT optical observations
  33. GRB 260515A: OHP/T193 optical observations
  34. EP260514a: COLIBRÍ optical upper limits
  35. GRID detection of GRB 260507A
  36. GRB 260515A: GTC/OSIRIS+ spectroscopic redshift z = 0.764
  37. GRB 260515A: LCO optical observations
  38. SVOM GRB 260515A: Global MASTER-Net observations report
  39. GRB 260515A: NOT optical observations.
  40. SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
  41. GRB 260515A: SVOM/VT optical candidate from VHF data
  42. GRB 260515A: JinShan optical counterpart candidate
  43. GRB 260510C: Glowbug gamma-ray detection
  44. IceCube-260504A: No Candidate Transients from the Zwicky Transient Facility
  45. EP260514a: GROWTH-India Telescope optical upper limit
  46. GRB 260511B: NOT optical observations
  47. Konus-Wind detection of GRB 260512A
  48. GRB 260510C: CALET Gamma-Ray Burst Monitor detection
  49. GRB 260511B: GMG Optical Upper Limit
  50. EP260514a: Global MASTER-Net observations report
  51. EP260512a: LCO optical upper limits
  52. IPN triangulation of GRB 260512A
  53. GRB 260511B: Mephisto multi-band optical followup
  54. Fermi GRB 260514A: Global MASTER-Net observations report
  55. GRB 260512A: AstroSat CZTI detection
  56. EP260512a: EP-FXT follow-up observation
  57. EP260507a: Xinglong Schmidt optical counterpart detection
  58. EP260512a: Global MASTER-Net observations report
  59. Fermi GRB 260513A: Global MASTER-Net observations report
  60. Fermi GRB 260512A: Global MASTER-Net observations report
  61. GRB 260511B: further SAO RAS optical observations
  62. GRB 260509A: SVOM/VT optical observations
  63. Konus-Wind detection of GRB 260511B
  64. EP260512a: COLIBRÍ optical upper limits
  65. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  66. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  67. GRB 260512A: NuSTAR detection of prompt emission
  68. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  69. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  70. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  71. GRB 260511A: Glowbug gamma-ray detection
  72. Konus-Wind detection of GRB 260511A
  73. MASS-Cube (GRID 2.0) detection of GRB 260511A
  74. MASS-Cube (GRID 2.0) detection of GRB 260507A
  75. GRB 260511B: SAO RAS optical observations
  76. GRB 260510D: Glowbug gamma-ray detection of a likely short burst
  77. GRB 260511B: FRAM-ORM optical detection
  78. GRB 260511A: EP-FXT follow-up observation
  79. GRB 260511B: EP-FXT follow-up observation
  80. GRB 260511B: LCO optical counterpart detection
  81. GRB260511B: MAO/AZT-22 optical observations
  82. GRB 260511A: SVOM/VT optical observations
  83. GRB 260511B: LCO optical observations
  84. GRB 260511B: OHP/T193 spectroscopic observations
  85. GRB 260511B: GOTO optical counterpart detection
  86. GRB 260511B: Xinglong 2.16m/BEFOSC redshift confirmation
  87. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  88. GRB 260511B: SVOM/VT optical observations
  89. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  90. GRB 260510B: EP-FXT follow-up observation
  91. GRB 260511B: OSIRIS+/GTC redshift z=2.006
  92. GRB 260510C: Fermi GBM Observation
  93. GRB 260509A: SAO RAS optical observations
  94. GRB 260511A: REM near-infrared detection
  95. GRB 260511B: GROWTH-India Telescope optical observations
  96. GRB 260511B: AstroSat CZTI detection
  97. GRB 260506B: Glowbug gamma-ray detection
  98. GRB 260506A: Glowbug gamma-ray detection of a short burst
  99. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  100. GRB 260511B: NuSTAR detection of prompt emission

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