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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"

26484 results found.

  1. Fermi-LAT Gamma-ray Observations of IceCube-260704A
  2. IceCube-260708A: Upper limits from a search for additional neutrino events in IceCube
  3. GRB 260708A: LCO optical observations
  4. EP260711a: Einstein Probe detection of an X-ray transient
  5. GRB 260710A: Fermi GBM Detection
  6. GRB 260709A: SVOM/GRM detection
  7. GRB 260709A: GECAM-B observation
  8. The EP-WXT trigger 01709274666 is likely a new outburst of the CV SS Cyg
  9. IceCube-260708A: Observations with the Vera C. Rubin Observatory
  10. EP-WXT trigger 0170924151 : RAPAS optical counterpart candidate detection
  11. GRB 260708A: Glowbug gamma-ray detection
  12. GRB 260704A: SVOM/ECLAIRs refined analysis
  13. GRB 260706A : GRANDMA Upper limits
  14. GRB 260708A: Kilonova-Catcher optical afterglow detection
  15. IceCube-260708A: One candidate from the Zwicky Transient Facility
  16. GRB 260708A: Fermi-GBM observation
  17. Fermi LAT GRB 260708A: MASTER OT J150237.02-435307.7 optical counterpart detection
  18. GRB 260705B: SVOM/GRM observation
  19. GRB 260706A: Further EP-FXT follow-up observation
  20. EP260707a (by EP-FXT): NOT optical upper limit
  21. EP260707a is not a real source
  22. EP260707a: LCOGT Optical Upper Limit
  23. EP260707a: TRT optical upper limit
  24. EP260707a: Einstein Probe detection of an X-ray transient
  25. GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
  26. GRB 260705C: Glowbug gamma-ray detection of a short burst
  27. GRB 260706A: SVOM/ECLAIRs refined analysis
  28. GRB 260704A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  29. GRB 260706A: SVOM/GRM observation
  30. GRB 260706A: REM optical/NIR observations
  31. GRB 260706A: LCO optical upper limit
  32. GRB 260706A: EP-FXT follow-up observation
  33. The EP-WXT trigger 01709274141 is likely a flaring star
  34. GRB 260706A: Fermi GBM Observation
  35. IceCube-260704A: Upper limits from a search for additional neutrino events in IceCube
  36. GRB 260706A: SVOM detection of a burst
  37. The EP-WXT trigger 01709274014 is likely a flaring star
  38. IceCube260704A: OHP/T193 optical observations
  39. GRB 260705A: LCO optical upper limits
  40. GRB 260704A: NOT optical upper limits
  41. GRB 260705A: SVOM detection of a burst
  42. GRB 260704A: EP-FXT follow-up observation
  43. GRB 260629A: SVOM/GRM observation of a short burst
  44. EP260703a: EP-FXT follow-up observation
  45. GRB 260704A: SVOM detection of a possible GRB
  46. EP260703a: EP-WXT detection of a fast X-ray transient
  47. EP260628b: EP-WXT detection of an X-ray transient and EP-FXT follow-up observation
  48. Fermi GRB 260703A: Global MASTER-Net observations report
  49. GRB 260623A: Glowbug gamma-ray detection
  50. GRB 260610B / AT2026owq: SAO RAS, CrAO and INASAN further optical observations and light curve
  51. Fermi-LAT Gamma-ray Observations of IceCube-260622A
  52. EP260628a: EP-FXT follow-up observation
  53. EP260628a: EP-WXT detection of a fast X-ray transient
  54. The EP-WXT trigger 01709272671 is likely a flaring star
  55. EP260626a: further Liverpool Telescope optical upper limits
  56. EP260626a: EP-FXT follow-up observation
  57. EP260626a: COLIBRÍ optical upper limit
  58. EP260626a: Liverpool Telescope upper limits
  59. EP260626a: EP-WXT detection of a fast X-ray transient
  60. Konus-Wind detection of GRB 260623B / EP260623a
  61. EP260623a: TNG NIR afterglow detection
  62. GRB 260618A: Fermi GBM Observation
  63. EP260623a: Liverpool Telescope optical observations
  64. Konus-Wind detection of GRB 260618B
  65. EP260623a:refined analysis of the EP-WXT and EP-FXT observation
  66. EP260623a: WINTER J-band observations
  67. GRB 260617A: Glowbug gamma-ray detection of a short burst
  68. IceCube-260622A: Upper limits from a search for additional neutrino events in IceCube
  69. EP260623a: Optical follow-up observations with Kinder
  70. EP260623a: SVOM/VT optical observations
  71. EP260623a: TRT optical observations
  72. EP260623a: REM optical/NIR afterglow detection
  73. EP 260623a: COLIBRÍ optical observations
  74. EP260623a: OSIRIS+/GTC redshift z = 0.703
  75. EP260623a: Las Cumbres discovery of the optical counterpart
  76. EP260623a: Einstein Probe detection of an X-ray transient
  77. GRB 260614B: EP-FXT follow-up observation
  78. GRB 260618C: SVOM/ECLAIRs detection of a possible burst through on-ground search
  79. EP260618a: Liverpool Telescope optical observations
  80. GRB 260618B: LCO optical observations
  81. The EP-WXT trigger 01709271197 is likely a flaring star
  82. EP260618a: JinShan optical observations
  83. GRB 260616B/EP260616a: SVOM/GRM detection of a burst
  84. GRB 260618B: Fermi GBM Observation
  85. IceCube-Cascade 260618A: Upper limits from a search for additional neutrino events in IceCube
  86. GRB 260619A: TRT optical counterpart confirmation
  87. GRB 260610B: Further GRANDMA Optical Observations and re-brightening detection
  88. Fermi-LAT Gamma-ray Observations of IceCube-260610A
  89. GRB 260619A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  90. Konus-Wind detection of GRB 260617A
  91. GRB 260616B: AstroSat CZTI detection
  92. GRB 260616A: AstroSat CZTI detection
  93. GRB 260616A: SVOM/GRM observation
  94. EP260618a: OHP/T193 optical observations
  95. GRB 260610B/AT2026owq: 1.3m DFOT optical rebrightening detection
  96. GRB 260619A: Kilonova-Catcher optical upper limit
  97. EP260618a: EP-FXT follow-up observation
  98. EP260618a: LCO optical counterpart confirmation
  99. EP260618a: COLIBRÍ optical counterpart candidate
  100. GRB 260619A: SVOM possible detection of a faint burst

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