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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"

43125 results found.

  1. GRB 250114B: Swift ToO observations
  2. EP250111a: SAO RAS optical upper limit
  3. LIGO/Virgo/KAGRA S250114ax: NED Galaxies in the Localization Volume
  4. GRB 250114B: a short GRB detected with INTEGRAL
  5. EP250108a: correction to GCN 38908
  6. GRB 250114A: Enhanced Swift-XRT position
  7. GRB 250113A: INTEGRAL/SPI-ACS detection
  8. GRB 250114A: VLT/X-shooter spectroscopic redshift z = 4.732
  9. GRB 250114A: REM detection of the optical and NIR counterpart
  10. LIGO/Virgo/KAGRA S250114ax: Identification of a GW compact binary merger candidate
  11. Swift GRB250114A: Global MASTER-Net OT detection
  12. GRB 250114A: LCO optical observations
  13. GRB 250114A: TRT optical observations
  14. Swift GRB 250114A: Global MASTER-Net observations report
  15. GRB 250114A: Swift detection of a burst with an optical counterpart
  16. EP250108a / AT 2025kg: SAO RAS optical observations
  17. EP241021a: SMA radio observation
  18. GRB 250113A: SVOM/GRM observation of a long burst
  19. GRB 250107A: VZLUSAT-2 detection
  20. EP250109b: optical upper limits with the Liverpool Telescope
  21. GRB 250109A / EP250109a: GRBAlpha detection
  22. GRB 250107D: GRBAlpha detection
  23. GRB 250106A: Swift-XRT afterglow detection
  24. Fermi trigger No 758442826: Global MASTER-Net observations report
  25. EP250111a: KAIT optical observations
  26. GRB 250109A / EP250109a: Mephisto optical upper limits
  27. EP250108a: Mephisto detection
  28. EP250108a / AT 2025kg: LCO optical observations
  29. EP250111a: Global MASTER-Net observations report
  30. EP250111a: Swift/XRT detection and fading
  31. EP250108a / AT 2025kg: Swift UVOT detections
  32. EP250108a / AT 2025kg (the "kangaroo”): VLT/X-shooter spectroscopic redshift z = 0.176 and LFBOT classification
  33. EP250108a: optical follow-up observations with the Liverpool Telescope
  34. EP250111a: NOT likely optical counterpart
  35. EP250111a: a new X-ray transient detected by Einstein Probe
  36. EP250109a/GRB 250109A:SVOM/VT optical counterpart
  37. GRB 250101B: Fermi GBM Observation
  38. EP250108a: further NOT optical observations
  39. GRB 250109A / EP250109a: Terskol (INASAN) and SAO RAS observations
  40. GRB 250109A / EP250109A: Swift/BAT-GUANO localization skymap of a burst
  41. GRB 250109A / EP250109a: Swift detection of the X-ray afterglow
  42. GRB 250108A: Swift/XRT afterglow fading
  43. GRB 250107D: CALET Gamma-Ray Burst Monitor detection
  44. GRB 250107C: CALET Gamma-Ray Burst Monitor detection
  45. Konus-Wind detection of GRB 250107C
  46. LIGO/Virgo/KAGRA S250109bi: Updated Sky localization
  47. LIGO/Virgo/KAGRA S250109f: Updated Sky localization
  48. LIGO/Virgo/KAGRA S250108eo: Updated Sky localization
  49. EP250109a / GRB 250109A: refined EP-WXT analysis and EP-FXT follow-up observation
  50. EP250108a: EP-FXT follow-up observation
  51. GRB 250109A: Fermi GBM Observation
  52. The EP-WXT trigger 01709130111 is likely a flaring star
  53. EP250108a: NOT optical observations
  54. GRB 250109a: GMG Optical Upper Limit
  55. EP250109a: Swift/UVOT non-detection
  56. Konus-Wind detection of GRB 250107D (short/hard)
  57. IPN triangulation of GRB 250107D (short/hard)
  58. IPN triangulation of GRB 250107C
  59. EP250108a: Liverpool Telescope likely optical counterpart
  60. GRB 250108B: Gemini-North likely redshift z = 2.197
  61. GRB 250108B: 1.3m DFOT upper limit
  62. GRB 250108B: REM optical/NIR upper limits
  63. GRB 250109A /EP250109a: Fermi GBM Final Localization
  64. EP250109a: SVOM/VT optical candidate
  65. EP250109a: Global MASTER-Net observations report
  66. GRB 250107C: SVOM/GRM observation
  67. GRB 250101A: Terskol K-800 optical observations
  68. EP250109a: GOTO optical upper limits
  69. EP250109a: Swift/XRT non-detection
  70. GRB 250108A: Swift/UVOT Upper Limits
  71. EP250108a: Global MASTER-Net observations report
  72. EP250109a: EP-WXT detection of an X-ray transient
  73. LIGO/Virgo/KAGRA S250109bi: Identification of a GW compact binary merger candidate
  74. GRB 250108A: NOT optical upper limit
  75. EP250108a: EP-WXT detection of an X-ray transient
  76. LIGO/Virgo/KAGRA S250109f: Identification of a GW compact binary merger candidate
  77. GRB 250108B: Swift-XRT refined Analysis
  78. Swift GRB 250108B: Global MASTER-Net observations report
  79. LIGO/Virgo/KAGRA S250108ha: Retraction of GW compact binary merger candidate
  80. GRB 250108B: Gemini-North Candidate Optical Afterglow Detection
  81. GRB 250103A: 1.6m Mephisto optical observations
  82. GRB 250108A: Swift-XRT afterglow detection
  83. GRB 250108A:SVOM/VT optical candidate
  84. LIGO/Virgo/KAGRA S250108eo: Identification of a GW compact binary merger candidate
  85. GRB 250108B: Swift/UVOT Upper Limits
  86. GRB 250103A: Swift-XRT afterglow detection
  87. GRB 250108B: Enhanced Swift-XRT position
  88. GRB 250108B: Swift detection of a burst
  89. GRB 250108A: Swift ToO observations
  90. GRB 250108A: SVOM detection of a soft long burst
  91. GRB 250107A: Fermi GBM Observation
  92. GRB 241228B: Fermi-LAT detection
  93. Fermi GRB 250107B: Global MASTER-Net observations report
  94. GRB 250107A: Swift ToO observations
  95. GRB 250107A: Swift/BAT-GUANO arcminute localization of a burst
  96. GRB 250107B: Fermi GBM Final Real-time Localization
  97. GRB 250106A: SVOM/VT 2nd optical deep observation
  98. GRB 250107A: Fermi GBM Final Real-time Localization
  99. EPWXT01709129925: Xinglong optical observations
  100. GRB 250106A: NOT optical observations

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