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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

24658 results found.

  1. GRB 241213A: Swift-XRT refined Analysis
  2. GRB 241212A: Fermi GBM detection
  3. EP241208a: NOT optical upper limits
  4. GRB 241213A: LCOGT Optical Upper Limits
  5. GRB 241213B: MAXI/GSC detection
  6. EP241213a: EP detection of An X-ray Transient
  7. GRB 241213A: REM optical/NIR upper limits
  8. GRB 241213A: Enhanced Swift-XRT position
  9. GRB241212A: OHP/T193 optical observations
  10. GRB 241213A: SAO RAS optical upper limit
  11. LIGO/Virgo/KAGRA S241210fu: Updated Sky localization
  12. GRB 241213A: Swift detection of a burst
  13. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  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 241207A: EIRSAT-1 GMOD Detection
  19. LIGO/Virgo/KAGRA S241210cw: Updated Sky localization
  20. LIGO/Virgo/KAGRA S241210d: Updated Sky localization and EM Bright Classification
  21. GRB 241129A: Fermi GBM Observation
  22. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  23. GRB 241209D: REM optical/NIR upper limits
  24. GRB 241209B: Swift-XRT afterglow detection
  25. GRB 241209C: Fermi GBM Observation
  26. GRB 241209A: Swift-XRT refined Analysis
  27. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  28. EP241208a: Optical upper limit with Kinder observations
  29. GRB 241209B: SVOM/VT afterglow detection
  30. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  31. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  32. GRB 241207B: Fermi GBM Observation
  33. GRB 241209D: Swift-XRT refined Analysis
  34. GRB 241209D: Fermi GBM Observation
  35. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  36. GRB 241209D: COLIBRÍ detection of the afterglow
  37. GRB 241209A: COLIBRÍ Optical Upper Limit
  38. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  39. GRB 241209A: GRANDMA/TAROT upper limit
  40. GRB 241209A: REM optical/NIR observations
  41. GRB 241209D: Enhanced Swift-XRT position
  42. GRB 241209D: Swift detection of a burst
  43. GRB 241209A: Enhanced Swift-XRT position
  44. GRB 241114B: cubesat Avion detection
  45. GRB 241209A: VLT optical observations
  46. GRB 241209A: GOTO optical upper limits
  47. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  48. EP241208a: EP detection of a fast X-ray transient
  49. GRB 241209A: Swift detection of a short burst
  50. Fermi GRB 241207B: Global MASTER-Net observations report
  51. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  52. GRB 241206A: DDOTI Upper Limit on the Afterglow
  53. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  54. GRB 241207C: MAXI/GSC detection
  55. EP241206a: EP detection of a fast X-ray transient
  56. GRB 241206A: Fermi GBM observation
  57. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  58. EP241201a: 1.6m Mephisto Optical Upper Limits
  59. GRB 241204A: COLIBRÍ Optical Upper Limit
  60. EP241202b: KAIT optical upper limit
  61. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  62. GRB 241204A: DDOTI Upper Limits on the Afterglow
  63. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  64. GRB 241128A : RAPAS follow-up observations
  65. EP241202b: Upper limits from Fermi-GBM Observations
  66. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  67. EP241202b: Kinder optical counterpart candidate
  68. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  69. GRB 241113B : RAPAS follow-up observation
  70. Konus-Wind detection of GRB 241130A
  71. EP241201a: BOOTES-5 optical upper limit
  72. EP241202b: EP detection of a fast X-ray transient
  73. EP241201a: NOT optical observations
  74. IPN triangulation of GRB 241130A
  75. GRB 241130A: EIRSAT-1 GMOD Detection
  76. GRB 241128A: Swift/UVOT Upper Limits
  77. GRB 241130A: Fermi GBM Detection
  78. IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube
  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. LIGO/Virgo/KAGRA S241201ac: Updated Sky localization
  83. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  84. EP241126a: 1.6m Mephisto Optical Upper Limits
  85. GRB 241201A: Fermi GBM Final Real-time Localization
  86. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  87. LIGO/Virgo/KAGRA S241130be: Updated Sky localization
  88. Fermi trigger No 754701230: Global MASTER-Net observations report
  89. LIGO/Virgo/KAGRA S241130n: Updated Sky localization
  90. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  91. GRB 241128A: AbAO optical upper limit
  92. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  93. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  94. LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
  95. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  96. GRB 241128A: Swift-BAT refined analysis
  97. GRB 241127A: Swift-BAT refined analysis
  98. GRB 241127A: PRIME near-infrared detection
  99. GRB 241128A: Mondy optical observations
  100. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits

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