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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"

45727 results found.

  1. EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
  2. EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
  3. GRB 241213B: MAXI/GSC detection
  4. EP241213a: EP detection of An X-ray Transient
  5. GRB 241213A: REM optical/NIR upper limits
  6. GRB 241213A: Enhanced Swift-XRT position
  7. GRB241212A: OHP/T193 optical observations
  8. GRB 241213A: SAO RAS optical upper limit
  9. LIGO/Virgo/KAGRA S241210fu: Updated Sky localization
  10. Swift GRB 241213A: Global MASTER-Net observations report
  11. GRB 241213A: Swift detection of a burst
  12. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  13. GRB 241212A : SVOM/VT bright optical afterglow
  14. GRB 241212A: AstroSat CZTI detection
  15. GRB 241209B: GRANDMA/TRT upper limit
  16. GRB 241207A: TSHAO Zeiss-1000 optical observations
  17. GRB 241212A: SVOM detection of a bright long burst
  18. GRB 241212A: Fermi GBM Final Real-time Localization
  19. GRB 241209B: Mondy AZT-33IK and AbAO AS-32 optical observations
  20. GRB 241209A: Chandra X-ray Detection
  21. Konus-Wind detection of GRB 241209B
  22. GRB 241207A: EIRSAT-1 GMOD Detection
  23. GRB 241209A: Redshift of the likely host galaxy z = 0.784 from OSIRIS+/GTC
  24. GRB 241209B: GRBAlpha detection
  25. GRB 241206C: GRBAlpha detection
  26. LIGO/Virgo/KAGRA S241210cw: Updated Sky localization
  27. LIGO/Virgo/KAGRA S241210d: Updated Sky localization and EM Bright Classification
  28. GRB 241211A: Fermi GBM Final Real-time Localization
  29. GRB 241129A: Fermi GBM Observation
  30. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  31. GRB 241209D: REM optical/NIR upper limits
  32. Konus-Wind detection of GRB 241209D
  33. GRB 241209B: Swift-XRT afterglow detection
  34. GRB 241209C: Fermi GBM Observation
  35. GRB 241209A: Swift-XRT refined Analysis
  36. Fermi Gamma-ray Burst Monitor trigger 755485387 / 241210044 is not a GRB
  37. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  38. EP241208a: Optical upper limit with Kinder observations
  39. GRB 241128A: CrAO ZTSh and Mondy AZT-33IK optical observations
  40. GRB 241209D: AstroSat CZTI detection
  41. GRB 241209A: EP-FXT follow-up observations
  42. GRB 241209B: SVOM/VT afterglow detection
  43. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  44. EP241208a: Global MASTER-Net observations report
  45. EP241208a: EP-FXT follow-up observations
  46. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  47. Fermi trigger No 755485387: Global MASTER-Net observations report
  48. GRB 241207B: Fermi GBM Observation
  49. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  50. GRB 241209D: Swift-XRT refined Analysis
  51. GRB 241209D: Fermi GBM Observation
  52. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  53. GRB 241209D: COLIBRÍ detection of the afterglow
  54. GRB 241209A: COLIBRÍ Optical Upper Limit
  55. Fermi GRB 241209D: Global MASTER-Net observations report
  56. GRB 241209A: Fermi GBM Observation
  57. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  58. GRB 241209A: GRANDMA/TAROT upper limit
  59. GRB 241209B: BOOTES-5 optical upper limit
  60. Swift GRB 241209D: Global MASTER-Net observations report
  61. Fermi GRB 241209C: Global MASTER-Net observations report
  62. Fermi GRB 241209E: Global MASTER-Net observations report
  63. GRB 241209E: Fermi GBM Final Real-time Localization
  64. GRB 241209B: Swift ToO observations
  65. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
  66. GRB 241209A: REM optical/NIR observations
  67. GRB 241209D: Enhanced Swift-XRT position
  68. GRB 241209C: AstroSat CZTI detection
  69. GRB 241209D: Swift detection of a burst
  70. GRB 241209D: Fermi GBM Final Real-time Localization
  71. GRB 241209A: VLT/X-shooter spectroscopy
  72. GRB 241209A: Enhanced Swift-XRT position
  73. GRB 241114B: cubesat Avion detection
  74. GRB 241209A: VLT optical observations
  75. Fermi GRB 241209A: Global MASTER-Net observations report
  76. GRB 241209C: Fermi GBM Final Real-time Localization
  77. GRB 241209A: GOTO optical upper limits
  78. EP241206a: 1.5m OSN optical limit
  79. GRB 241209A: Prompt enhanced Swift-XRT position
  80. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  81. EP241208a: EP detection of a fast X-ray transient
  82. GRB 241209A: Swift detection of a short burst
  83. Swift GRB241209.23: Global MASTER-Net observations report
  84. GRB 241209A: Fermi GBM Final Real-time Localization
  85. Fermi GRB 241207B: Global MASTER-Net observations report
  86. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  87. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  88. GRB 241201A: AstroSat CZTI detection
  89. GRB 241206A: DDOTI Upper Limit on the Afterglow
  90. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  91. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  92. EP241206a: BOOTES Global Network optical limits
  93. GRB 241207C: MASTER optical observations
  94. Fermi trigger No 755225799: Global MASTER-Net observations report
  95. GRB 241207C: Tiled Swift observations
  96. GRB 241207C: MAXI/GSC detection
  97. GRB 241207B: Fermi GBM Final Real-time Localization
  98. Fermi trigger No 755277791: Global MASTER-Net observations report
  99. Fermi GRB 241207A: Global MASTER-Net observations report
  100. EP241206a: Global MASTER-Net observations report

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