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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

45722 results found.

  1. GRB 241213A: Enhanced Swift-XRT position
  2. GRB241212A: OHP/T193 optical observations
  3. GRB 241213A: SAO RAS optical upper limit
  4. LIGO/Virgo/KAGRA S241210fu: Updated Sky localization
  5. Swift GRB 241213A: Global MASTER-Net observations report
  6. GRB 241213A: Swift detection of a burst
  7. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  8. GRB 241212A : SVOM/VT bright optical afterglow
  9. GRB 241212A: AstroSat CZTI detection
  10. GRB 241209B: GRANDMA/TRT upper limit
  11. GRB 241207A: TSHAO Zeiss-1000 optical observations
  12. GRB 241212A: SVOM detection of a bright long burst
  13. GRB 241212A: Fermi GBM Final Real-time Localization
  14. GRB 241209B: Mondy AZT-33IK and AbAO AS-32 optical observations
  15. GRB 241209A: Chandra X-ray Detection
  16. Konus-Wind detection of GRB 241209B
  17. GRB 241207A: EIRSAT-1 GMOD Detection
  18. GRB 241209A: Redshift of the likely host galaxy z = 0.784 from OSIRIS+/GTC
  19. GRB 241209B: GRBAlpha detection
  20. GRB 241206C: GRBAlpha detection
  21. LIGO/Virgo/KAGRA S241210cw: Updated Sky localization
  22. LIGO/Virgo/KAGRA S241210d: Updated Sky localization and EM Bright Classification
  23. GRB 241211A: Fermi GBM Final Real-time Localization
  24. GRB 241129A: Fermi GBM Observation
  25. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  26. GRB 241209D: REM optical/NIR upper limits
  27. Konus-Wind detection of GRB 241209D
  28. GRB 241209B: Swift-XRT afterglow detection
  29. GRB 241209C: Fermi GBM Observation
  30. GRB 241209A: Swift-XRT refined Analysis
  31. Fermi Gamma-ray Burst Monitor trigger 755485387 / 241210044 is not a GRB
  32. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  33. EP241208a: Optical upper limit with Kinder observations
  34. GRB 241128A: CrAO ZTSh and Mondy AZT-33IK optical observations
  35. GRB 241209D: AstroSat CZTI detection
  36. GRB 241209A: EP-FXT follow-up observations
  37. GRB 241209B: SVOM/VT afterglow detection
  38. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  39. EP241208a: Global MASTER-Net observations report
  40. EP241208a: EP-FXT follow-up observations
  41. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  42. Fermi trigger No 755485387: Global MASTER-Net observations report
  43. GRB 241207B: Fermi GBM Observation
  44. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  45. GRB 241209D: Swift-XRT refined Analysis
  46. GRB 241209D: Fermi GBM Observation
  47. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  48. GRB 241209D: COLIBRÍ detection of the afterglow
  49. GRB 241209A: COLIBRÍ Optical Upper Limit
  50. Fermi GRB 241209D: Global MASTER-Net observations report
  51. GRB 241209A: Fermi GBM Observation
  52. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  53. GRB 241209A: GRANDMA/TAROT upper limit
  54. GRB 241209B: BOOTES-5 optical upper limit
  55. Swift GRB 241209D: Global MASTER-Net observations report
  56. Fermi GRB 241209C: Global MASTER-Net observations report
  57. Fermi GRB 241209E: Global MASTER-Net observations report
  58. GRB 241209E: Fermi GBM Final Real-time Localization
  59. GRB 241209B: Swift ToO observations
  60. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
  61. GRB 241209A: REM optical/NIR observations
  62. GRB 241209D: Enhanced Swift-XRT position
  63. GRB 241209C: AstroSat CZTI detection
  64. GRB 241209D: Swift detection of a burst
  65. GRB 241209D: Fermi GBM Final Real-time Localization
  66. GRB 241209A: VLT/X-shooter spectroscopy
  67. GRB 241209A: Enhanced Swift-XRT position
  68. GRB 241114B: cubesat Avion detection
  69. GRB 241209A: VLT optical observations
  70. Fermi GRB 241209A: Global MASTER-Net observations report
  71. GRB 241209C: Fermi GBM Final Real-time Localization
  72. GRB 241209A: GOTO optical upper limits
  73. EP241206a: 1.5m OSN optical limit
  74. GRB 241209A: Prompt enhanced Swift-XRT position
  75. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  76. EP241208a: EP detection of a fast X-ray transient
  77. GRB 241209A: Swift detection of a short burst
  78. Swift GRB241209.23: Global MASTER-Net observations report
  79. GRB 241209A: Fermi GBM Final Real-time Localization
  80. Fermi GRB 241207B: Global MASTER-Net observations report
  81. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  82. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  83. GRB 241201A: AstroSat CZTI detection
  84. GRB 241206A: DDOTI Upper Limit on the Afterglow
  85. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  86. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  87. EP241206a: BOOTES Global Network optical limits
  88. GRB 241207C: MASTER optical observations
  89. Fermi trigger No 755225799: Global MASTER-Net observations report
  90. GRB 241207C: Tiled Swift observations
  91. GRB 241207C: MAXI/GSC detection
  92. GRB 241207B: Fermi GBM Final Real-time Localization
  93. Fermi trigger No 755277791: Global MASTER-Net observations report
  94. Fermi GRB 241207A: Global MASTER-Net observations report
  95. EP241206a: Global MASTER-Net observations report
  96. EP241206a: EP detection of a fast X-ray transient
  97. GRB 241206A: Fermi GBM observation
  98. GRB 241206C: SVOM/GRM observation of a likely short burst
  99. GRB 241207A: Fermi GBM Final Real-time Localization
  100. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst

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