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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.

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

32722 results found.

  1. Konus-Wind detection of GRB 250807A
  2. GRB 250807B: Swift/UVOT Detection
  3. GRB 250807B: Kilonova-Catcher optical afterglow detection
  4. IceCube-250804A: Upper limits from a search for additional neutrino events in IceCube
  5. GRB 250807A: Swift/UVOT Detection
  6. GRB 250807B: VLT/X-Shooter spectroscopic redshift z = 1.522
  7. GRB 250806A: SVOM/MXT refined analysis
  8. GRB 250806A: SVOM/ECLAIRs refined analysis
  9. EP250807a: NTT z-band optical upper limit
  10. GRB 250806A: Mondy optical observations, and nearby bright galaxy photometry
  11. GRB 250804B: Insight-HXMT detection
  12. GRB 250807A: SVOM/GRM observation
  13. GRB 250807A: AstroSat CZTI detection of bright long burst
  14. GRB 250806A: NOT z-band upper limit and host galaxy candidate
  15. GRB 250807B: NTT optical observations
  16. EP250807a: EP-WXT detection of a fast X-ray transient
  17. GRB 250807A: SVOM/VT optical observation
  18. EP250806a: Upper limit from Fermi-GBM Observations
  19. GRB 250805A: Kilonova-Catcher optical upper limits
  20. EP250806a:SVOM/VT refined analysis
  21. GRB 250805A: Swift/UVOT Upper Limits
  22. GRB 250806A: Swift/UVOT U-band detection
  23. EP250806a: Liverpool telescope optical upper limit
  24. GRB 250806A: EP-FXT observation
  25. EP#01709198415/EP250806a: Swift-XRT observations
  26. EP250806a: Global MASTER-Net observations report
  27. EP250802a: EP-FXT follow-up observation
  28. EP250806a: refined analysis of the EP-WXT and EP-FXT observations
  29. EP250806a: Earlier Detection of the VT Candidate by COLIBRÍ and LS
  30. EP250806a: SVOM /VT optical candidate
  31. GRB 250806A: J-band upper limit from WINTER
  32. GRB 250805A: Swift-BAT refined analysis
  33. GRB 250806A: KAIT optical upper limit
  34. GRB 250806A: SVOM/VT refined analysis
  35. EP250806a: COLIBRÍ optical upper limit
  36. GRB 250806A: Kilonova-Catcher optical upper limits
  37. GRB 250806A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  38. GRB 250806A: SVOM/VT optical upper limit
  39. GRB 250805A: SVOM/VT optical counterpart
  40. GRB 250805A: ESO/VLT observations
  41. GRB 250805A: TRT optical upper limits
  42. GRB 250804B: Tiled Swift observations
  43. EP250802a: additional Liverpool Telescope upper limits
  44. EP250730a: SVOM/VT optical upper limit
  45. EP250802a: Liverpool Telescope optical upper limits
  46. EP250802a: Global MASTER-Net observations report
  47. EP250802a: GROWTH-India Telescope optical upper limit
  48. LIGO/Virgo/KAGRA S250802dn: Updated Sky localization
  49. LIGO/Virgo/KAGRA S250802dn: Identification of a GW compact binary merger candidate
  50. LIGO/Virgo/KAGRA S250727dc: GRANDMA/OPD observations of AT2025smm
  51. GRB 250702B: SMA observations
  52. LIGO/Virgo/KAGRA S250727dc: DECam GW-MMADS candidates
  53. LIGO/Virgo/KAGRA S250725j: GOTO pre-trigger detection of AT2025sib
  54. EP250711a: CrAO and Assy optical observations
  55. LIGO/Virgo/KAGRA S250727dc: DECam DESGW Epoch 1 Candidates
  56. EP250730a: Global MASTER-Net observations report
  57. EP250730a: COLIBRÍ optical upper limit
  58. GRB 250727A: Swift-XRT afterglow confirmation and refined analysis
  59. LIGO/Virgo/KAGRA S250725j: DECam DESGW Epoch 1-2 Candidates
  60. LIGO/Virgo/KAGRA S250727dc: Swift-XRT observations, 8 X-ray sources
  61. GRB 250725A: AstroSat CZTI detection
  62. GRB 250727A: EP-FXT follow-up observation
  63. GRB 250725A: PRIME near-infrared observations
  64. LIGO/Virgo/KAGRA S250727dc: DECam GW-MMADS upper limits of AT 2025smm
  65. LIGO/Virgo/KAGRA S250727dc: PRIME J-band upper limits of AT 2025smm
  66. GRB: Clarification on Gamma-Ray Burst Naming Convention
  67. GRB 250727A: SVOM/ECLAIRs refined analysis
  68. EP-WXT trigger 01709195487: confirmation of a stellar flare by BOOTES-6 & BOOTES-7
  69. GRB 250728A: COLIBRÍ optical upper limit
  70. GRB 250728A: Fermi GBM Observation
  71. LIGO/Virgo/KAGRA S250727dc: Updated Sky localization
  72. GRB 250728A: Swift ToO observations
  73. GRB 250728A: Swift/BAT-GUANO arcminute localization of a short burst
  74. GRB 250727A: AST3-2 Upper limit
  75. LIGO/Virgo/KAGRA S250727cl: Updated Sky localization
  76. GRB 250727A: EP-FXT counterpart detection
  77. GRB250727A: SVOM/VT optical upper limit
  78. LIGO/Virgo/KAGRA S250727dc: Identification of a GW compact binary merger candidate
  79. LIGO/Virgo/KAGRA S250727cl: Identification of a GW compact binary merger candidate
  80. LIGO/Virgo/KAGRA S250725j: DECam GW-MMADS candidates
  81. LIGO/Virgo/KAGRA S250725l: Updated Sky localization
  82. LIGO/Virgo/KAGRA S250726ak: Updated Sky localization
  83. LIGO/Virgo/KAGRA S250726ak: Identification of a GW compact binary merger candidate
  84. GRB 250725A: Fermi GBM Observation
  85. LIGO/Virgo/KAGRA S250725j: Updated Sky localization
  86. GRB 250725A: Swift-BAT refined analysis
  87. Konus-Wind detection of GRB 250725A
  88. GRB 250725A: SVOM/GRM observation
  89. GRB 250725A: Global MASTER-Net: First Optical Synchronous Observatios of Short GRB.
  90. GRB 250725A: Swift/UVOT Upper Limits
  91. GRB 250725A: Fermi-LAT detection
  92. GRB 250725A: VLT/FORS2 spectroscopic redshift z = 5.26
  93. GRB 250725A: BOOTES-7 early optical detection
  94. GRB 250725A: SVOM/VT optical candidate
  95. LIGO/Virgo/KAGRA S250725l: Identification of a GW compact binary merger candidate (duplicate submission)
  96. LIGO/Virgo/KAGRA S250725l: Identification of a GW compact binary merger candidate
  97. LIGO/Virgo/KAGRA S250725j: Identification of a GW compact binary merger candidate
  98. EP250702a/GRB250702 B,E,D: MeerKAT radio observations at 3.06 GHz
  99. SVOM J195836+32283 is not a real source
  100. SVOM J195836+32283/sb25072103: Second VT observation

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