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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"

27230 results found.

  1. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  2. GRB 241209D: COLIBRÍ detection of the afterglow
  3. GRB 241209A: COLIBRÍ Optical Upper Limit
  4. Fermi GRB 241209D: Global MASTER-Net observations report
  5. GRB 241209A: Fermi GBM Observation
  6. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  7. GRB 241209A: GRANDMA/TAROT upper limit
  8. GRB 241209B: BOOTES-5 optical upper limit
  9. Swift GRB 241209D: Global MASTER-Net observations report
  10. Fermi GRB 241209C: Global MASTER-Net observations report
  11. Fermi GRB 241209E: Global MASTER-Net observations report
  12. GRB 241209E: Fermi GBM Final Real-time Localization
  13. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
  14. GRB 241209A: REM optical/NIR observations
  15. GRB 241209D: Swift detection of a burst
  16. GRB 241209D: Fermi GBM Final Real-time Localization
  17. GRB 241209A: VLT optical observations
  18. Fermi GRB 241209A: Global MASTER-Net observations report
  19. GRB 241209C: Fermi GBM Final Real-time Localization
  20. GRB 241209A: GOTO optical upper limits
  21. EP241206a: 1.5m OSN optical limit
  22. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  23. EP241208a: EP detection of a fast X-ray transient
  24. GRB 241209A: Swift detection of a short burst
  25. Swift GRB241209.23: Global MASTER-Net observations report
  26. GRB 241209A: Fermi GBM Final Real-time Localization
  27. Fermi GRB 241207B: Global MASTER-Net observations report
  28. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  29. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  30. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  31. EP241206a: BOOTES Global Network optical limits
  32. GRB 241207C: MASTER optical observations
  33. Fermi trigger No 755225799: Global MASTER-Net observations report
  34. GRB 241207B: Fermi GBM Final Real-time Localization
  35. Fermi trigger No 755277791: Global MASTER-Net observations report
  36. Fermi GRB 241207A: Global MASTER-Net observations report
  37. EP241206a: Global MASTER-Net observations report
  38. EP241206a: EP detection of a fast X-ray transient
  39. GRB 241206A: Fermi GBM observation
  40. GRB 241206C: SVOM/GRM observation of a likely short burst
  41. GRB 241207A: Fermi GBM Final Real-time Localization
  42. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  43. GRB 241206B: SVOM/MXT observations: a probable flare from the QSO 1ES 1959+650
  44. GRB 241206B: SVOM/ECLAIRs detection of a long soft transient
  45. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  46. Fermi GRB 241206A: Global MASTER-Net observations report
  47. GRB 241206A: Fermi GBM Final Real-time Localization
  48. EP241201a: 1.6m Mephisto Optical Upper Limits
  49. GRB 241204A: COLIBRÍ Optical Upper Limit
  50. EP241202b: KAIT optical upper limit
  51. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  52. GRB 241204A: Fermi GBM Observation
  53. Fermi GRB 241204A: Global MASTER-Net observations report
  54. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  55. GRB 241201A: GRBAlpha detection
  56. GRB 241204A: Fermi-LAT detection
  57. EP241202b: Upper limits from Fermi-GBM Observations
  58. EP241202b: Kinder optical counterpart candidate
  59. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  60. EP241201a: EP-FXT follow-up observations
  61. EP241202b: Global MASTER-Net observations report
  62. EP241201a: BOOTES-5 optical upper limit
  63. EP241202b: EP detection of a fast X-ray transient
  64. EP241201a: NOT optical observations
  65. IPN triangulation of GRB 241130A
  66. GRB 241128A: Swift/UVOT Upper Limits
  67. GRB 241130A: Fermi GBM Detection
  68. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  69. EP241201a: Kinder optical counterpart candidate
  70. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  71. EP241201a: Global MASTER-Net observations report
  72. EP241201a: EP detection of a fast X-ray transient
  73. The EP-WXT trigger 01709126243 is not a real source
  74. GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
  75. GRB241201B: Fermi GBM Final Localization
  76. GRB241201B: Fermi GBM Final Localization
  77. EP241126a: SOAR observations of the optical counterpart
  78. Fermi GRB 241201A: Global MASTER-Net observations report
  79. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  80. GRB 241130A: Fermi GBM Final Real-time Localization
  81. GRB 241130A: Fermi GBM Final Real-time Localization
  82. EP241126a: 1.6m Mephisto Optical Upper Limits
  83. GRB 241201A: Fermi GBM Final Real-time Localization
  84. Fermi trigger No 754701230: Global MASTER-Net observations report
  85. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  86. SVOM/GRM observation of a short burst from soft gamma repeater Kes 73
  87. GRB 241128C: SVOM/GRM observation
  88. GRB 241128B: SVOM/GRM observation
  89. GRB 241128A: Swift-BAT refined analysis
  90. GRB 241127A: Swift-BAT refined analysis
  91. EP241126a: NOT optical observations
  92. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  93. Swift-XRT observations of IceCube -241127A
  94. Swift GRB 241128A: Global MASTER-Net observations report
  95. EP241126a: SVOM/VT observations
  96. GRB 241128A: Swift-XRT refined Analysis
  97. GRB 241129A: Fermi GBM Final Real-time Localization
  98. GRB 241128A: LCO optical detection
  99. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  100. Fermi trigger No 754492985: Global MASTER-Net observations report

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