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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').
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.

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

24705 results found.

  1. GRB 241218A: NOT optical upper limits
  2. GRB 241218A: Swift-BAT refined analysis
  3. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  4. EP 241217a: NIR detection with P200/WIRC
  5. EP 241217a: Possible J-band detection with WINTER
  6. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  7. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  8. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  9. GRB 241217A / EP241217b: NOT optical upper limits
  10. GRB 241218A: REM optical upper limit
  11. GRB 241217A/EP241217b: REM optical/NIR upper limits
  12. EP241217a: REM optical/NIR upper limits
  13. GRB 241217a: Liverpool Telescope optical follow-up
  14. EP241217a: Liverpool Telescope optical follow-up
  15. GRB 241218A: Swift-XRT refined Analysis
  16. EP241217a: NOT optical observations
  17. EP241217a: GROWTH-India Telescope optical observations
  18. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  19. EP241119a: 7DT Optical upper limits
  20. EP241217a: Xinglong optical follow-up observations
  21. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  22. GRB 241218A: LCOGT Optical Upper Limit
  23. GRB 241218A: Enhanced Swift-XRT position
  24. GRB 241217A: GMG Optical Upper Limit
  25. GRB 241218A: Swift detection of a burst
  26. GRB 241217A : SVOM/VT optical afterglow detection
  27. GRB 241217A: Swift-XRT afterglow detection
  28. GRB 241217A: LCO optical upper limit
  29. GRB 241217A: GRANDMA/TAROT optical upperlimits
  30. EP241217a: Swift-XRT Detection
  31. EP241217A: Non-detection from Fermi-GBM Observations
  32. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  33. EP241217a: Kinder optical follow-up observations
  34. EP241217A: LCO optical observations
  35. EP241217a: Gemini-North detection of the likely optical counterpart
  36. EP241217a: EP detection of an X-ray transient
  37. EP241107a: VLA Radio Observation
  38. GRB 241213A: Swift-BAT refined analysis
  39. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  40. GRB 241215A: Mondy AZT-33IK optical observations
  41. GRB 241212A: Swift-XRT observations
  42. GRB 241215A: Nanshan/HMT optical upper limit
  43. GRB 241215A: Montarrenti Observatory optical upper limit
  44. GRB 241215A: GROWTH-India telescope optical upper limit
  45. GRB 241215A: A long GRB detected by INTEGRAL
  46. Integral GRB241215.58: Global MASTER-Net observations report
  47. GRB 241213B: Swift-XRT observations
  48. GRB 241213A: Swift/UVOT Upper Limits
  49. GRB 241213A: Swift-XRT refined Analysis
  50. GRB 241212A: Fermi GBM detection
  51. EP241208a: NOT optical upper limits
  52. GRB 241213A: LCOGT Optical Upper Limits
  53. GRB 241213B: MAXI/GSC detection
  54. EP241213a: EP detection of An X-ray Transient
  55. GRB 241213A: REM optical/NIR upper limits
  56. GRB 241213A: Enhanced Swift-XRT position
  57. GRB241212A: OHP/T193 optical observations
  58. GRB 241213A: SAO RAS optical upper limit
  59. LIGO/Virgo/KAGRA S241210fu: Updated Sky localization
  60. GRB 241213A: Swift detection of a burst
  61. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  62. GRB 241212A: AstroSat CZTI detection
  63. GRB 241209B: GRANDMA/TRT upper limit
  64. GRB 241207A: TSHAO Zeiss-1000 optical observations
  65. GRB 241212A: SVOM detection of a bright long burst
  66. GRB 241207A: EIRSAT-1 GMOD Detection
  67. LIGO/Virgo/KAGRA S241210cw: Updated Sky localization
  68. LIGO/Virgo/KAGRA S241210d: Updated Sky localization and EM Bright Classification
  69. GRB 241129A: Fermi GBM Observation
  70. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  71. GRB 241209D: REM optical/NIR upper limits
  72. GRB 241209B: Swift-XRT afterglow detection
  73. GRB 241209C: Fermi GBM Observation
  74. GRB 241209A: Swift-XRT refined Analysis
  75. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  76. EP241208a: Optical upper limit with Kinder observations
  77. GRB 241209B: SVOM/VT afterglow detection
  78. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  79. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  80. GRB 241207B: Fermi GBM Observation
  81. GRB 241209D: Swift-XRT refined Analysis
  82. GRB 241209D: Fermi GBM Observation
  83. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  84. GRB 241209D: COLIBRÍ detection of the afterglow
  85. GRB 241209A: COLIBRÍ Optical Upper Limit
  86. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  87. GRB 241209A: GRANDMA/TAROT upper limit
  88. GRB 241209A: REM optical/NIR observations
  89. GRB 241209D: Enhanced Swift-XRT position
  90. GRB 241209D: Swift detection of a burst
  91. GRB 241209A: Enhanced Swift-XRT position
  92. GRB 241114B: cubesat Avion detection
  93. GRB 241209A: VLT optical observations
  94. GRB 241209A: GOTO optical upper limits
  95. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  96. EP241208a: EP detection of a fast X-ray transient
  97. GRB 241209A: Swift detection of a short burst
  98. Fermi GRB 241207B: Global MASTER-Net observations report
  99. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  100. GRB 241206A: DDOTI Upper Limit on the Afterglow

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