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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"

27241 results found.

  1. Fermi Gamma-ray Burst Monitor trigger 755485387 / 241210044 is not a GRB
  2. EP241208a: Optical upper limit with Kinder observations
  3. GRB 241209A: EP-FXT follow-up observations
  4. GRB 241209B: SVOM/VT afterglow detection
  5. EP241208a: Global MASTER-Net observations report
  6. EP241208a: EP-FXT follow-up observations
  7. Fermi trigger No 755485387: Global MASTER-Net observations report
  8. GRB 241207B: Fermi GBM Observation
  9. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  10. GRB 241209D: Swift-XRT refined Analysis
  11. GRB 241209D: Fermi GBM Observation
  12. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  13. GRB 241209D: COLIBRÍ detection of the afterglow
  14. GRB 241209A: COLIBRÍ Optical Upper Limit
  15. Fermi GRB 241209D: Global MASTER-Net observations report
  16. GRB 241209A: Fermi GBM Observation
  17. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  18. GRB 241209A: GRANDMA/TAROT upper limit
  19. GRB 241209B: BOOTES-5 optical upper limit
  20. Swift GRB 241209D: Global MASTER-Net observations report
  21. Fermi GRB 241209C: Global MASTER-Net observations report
  22. Fermi GRB 241209E: Global MASTER-Net observations report
  23. GRB 241209E: Fermi GBM Final Real-time Localization
  24. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
  25. GRB 241209A: REM optical/NIR observations
  26. GRB 241209D: Swift detection of a burst
  27. GRB 241209D: Fermi GBM Final Real-time Localization
  28. GRB 241209A: VLT optical observations
  29. Fermi GRB 241209A: Global MASTER-Net observations report
  30. GRB 241209C: Fermi GBM Final Real-time Localization
  31. GRB 241209A: GOTO optical upper limits
  32. EP241206a: 1.5m OSN optical limit
  33. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  34. EP241208a: EP detection of a fast X-ray transient
  35. GRB 241209A: Swift detection of a short burst
  36. Swift GRB241209.23: Global MASTER-Net observations report
  37. GRB 241209A: Fermi GBM Final Real-time Localization
  38. Fermi GRB 241207B: Global MASTER-Net observations report
  39. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  40. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  41. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  42. EP241206a: BOOTES Global Network optical limits
  43. GRB 241207C: MASTER optical observations
  44. Fermi trigger No 755225799: Global MASTER-Net observations report
  45. GRB 241207B: Fermi GBM Final Real-time Localization
  46. Fermi trigger No 755277791: Global MASTER-Net observations report
  47. Fermi GRB 241207A: Global MASTER-Net observations report
  48. EP241206a: Global MASTER-Net observations report
  49. EP241206a: EP detection of a fast X-ray transient
  50. GRB 241206A: Fermi GBM observation
  51. GRB 241206C: SVOM/GRM observation of a likely short burst
  52. GRB 241207A: Fermi GBM Final Real-time Localization
  53. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  54. GRB 241206B: SVOM/MXT observations: a probable flare from the QSO 1ES 1959+650
  55. GRB 241206B: SVOM/ECLAIRs detection of a long soft transient
  56. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  57. Fermi GRB 241206A: Global MASTER-Net observations report
  58. GRB 241206A: Fermi GBM Final Real-time Localization
  59. EP241201a: 1.6m Mephisto Optical Upper Limits
  60. GRB 241204A: COLIBRÍ Optical Upper Limit
  61. EP241202b: KAIT optical upper limit
  62. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  63. GRB 241204A: Fermi GBM Observation
  64. Fermi GRB 241204A: Global MASTER-Net observations report
  65. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  66. GRB 241201A: GRBAlpha detection
  67. GRB 241204A: Fermi-LAT detection
  68. EP241202b: Upper limits from Fermi-GBM Observations
  69. EP241202b: Kinder optical counterpart candidate
  70. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  71. EP241201a: EP-FXT follow-up observations
  72. EP241202b: Global MASTER-Net observations report
  73. EP241201a: BOOTES-5 optical upper limit
  74. EP241202b: EP detection of a fast X-ray transient
  75. EP241201a: NOT optical observations
  76. IPN triangulation of GRB 241130A
  77. GRB 241128A: Swift/UVOT Upper Limits
  78. GRB 241130A: Fermi GBM Detection
  79. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  80. EP241201a: Kinder optical counterpart candidate
  81. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  82. EP241201a: Global MASTER-Net observations report
  83. EP241201a: EP detection of a fast X-ray transient
  84. The EP-WXT trigger 01709126243 is not a real source
  85. GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
  86. GRB241201B: Fermi GBM Final Localization
  87. GRB241201B: Fermi GBM Final Localization
  88. EP241126a: SOAR observations of the optical counterpart
  89. Fermi GRB 241201A: Global MASTER-Net observations report
  90. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  91. GRB 241130A: Fermi GBM Final Real-time Localization
  92. GRB 241130A: Fermi GBM Final Real-time Localization
  93. EP241126a: 1.6m Mephisto Optical Upper Limits
  94. GRB 241201A: Fermi GBM Final Real-time Localization
  95. Fermi trigger No 754701230: Global MASTER-Net observations report
  96. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  97. SVOM/GRM observation of a short burst from soft gamma repeater Kes 73
  98. GRB 241128C: SVOM/GRM observation
  99. GRB 241128B: SVOM/GRM observation
  100. GRB 241128A: Swift-BAT refined analysis

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