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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').
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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"

28101 results found.

  1. LIGO/Virgo/KAGRA S250917aq: Updated Sky localization
  2. GRB 250916A: Glowbug gamma-ray detection
  3. GRB250917B: WFST optical observations
  4. GRB 250917B: Fermi GBM Observation
  5. GRB 250917B: Swift-XRT observations
  6. LIGO/Virgo/KAGRA S250917aq: Identification of a GW compact binary merger candidate
  7. GRB 250917B: Swift detection of a short burst
  8. GRB 250916A: AstroSat CZTI detection of a bright long burst
  9. EP250916a: Einstein Probe detection of an X-ray transient
  10. SVOM/sb25091517: SVOM detection of an X-ray transient
  11. GRB 250912A: Swift/BAT-GUANO localization skymap of a possibly short burst
  12. GRB 250912A: SVOM/COLIBRÍ (FM-GFT) optical observations
  13. GRB 250912A: Swift-XRT observations
  14. GRB250912A: VLT/HAWK-I follow-up observations
  15. GRB 250912A: Fermi GBM Observation
  16. GRB 250912A: SVOM/GRM analysis suggests a possible short GRB with extended emission
  17. GRB 250912A:SVOM/VT optical upper limit
  18. GRB 250912A: LCO optical upper limit
  19. EP250911a: Global MASTER-Net observations report
  20. GRB 250912A: SVOM detection of a burst
  21. IceCube-Cascade 250911A: Upper limits from a search for additional neutrino events in IceCube
  22. LIGO/Virgo/KAGRA S250912s: 2 counterpart neutrino candidate events from an IceCube neutrino search
  23. EP250911a: Upper limit from Fermi-GBM Observations
  24. LIGO/Virgo/KAGRA S250912f: Updated Sky localization
  25. GRB 250911A: GECAM-B detection
  26. GRB 250911A: Swift-BAT refined analysis
  27. LIGO/Virgo/KAGRA S250912f: Identification of a GW compact binary merger candidate
  28. EP250911a: refined analysis of the EP-WXT and EP-FXT observations
  29. GRB 250910B: SVOM/GRM observation
  30. EP250911a: SVOM/VT optical observation
  31. GRB 250911A: MASTER optical counterpart observations
  32. EP250911a: SAO RAS optical observations
  33. GRB 250911A: Swift-XRT refined Analysis
  34. EP250911a: Swift-XRT observations
  35. EP250911a: Optical detection with Kinder observations
  36. GRB 250911A: Swift/UVOT Detection
  37. GRB 250910A / EP250910a: Swift-XRT afterglow detection
  38. GRB 250910A / EP250910a: SVOM/VT afterglow confirmation
  39. LIGO/Virgo/KAGRA S250911ac: Updated Sky localization and Source Classification
  40. GRB 250910A / EP250910a : VLT/HAWK-I NIR counterpart discovery
  41. EP250911a: COLIBRÍ optical observations
  42. LIGO/Virgo/KAGRA S250908y: Updated Sky localization
  43. EP250911a: LCO optical counterpart discovery
  44. EP250911a: Einstein Probe detection of an X-ray transient
  45. LIGO/Virgo/KAGRA S250911ac: Identification of a GW compact binary merger candidate
  46. GRB 250903A: SVOM/ECLAIRs refined analysis
  47. GRB 250911A: Enhanced Swift-XRT position
  48. GRB 250911A: Swift-XRT observations
  49. GRB 250911A: COLIBRÍ optical counterpart candidate
  50. LIGO/Virgo/KAGRA S250906ca: Updated Sky localization
  51. GRB 250910B: BALROG localization (Fermi Trigger 779223130 / GRB 250910786)
  52. GRB 250910A / EP250910a: VLT/HAWK-I near-infrared observations
  53. EP250910a/GRB 250910A: EP-WXT detection of a fast X-ray transient
  54. GRB 250910A: SVOM/VT optical upper limit
  55. GRB 250910A: LCO optical upper limit
  56. EP250908b/EP#01709240653: Swift/UVOT Detection
  57. EP#01709240653: Swift-XRT observations
  58. EP250908c: refined analysis of the EP-WXT and EP-FXT observations
  59. EP250908c: SVOM/VT optical observation
  60. EP250908c: VLT/FORS2 optical counterpart identification
  61. EP250908b: SVOM/VT optical candidate (Coordinate supplement for GCN 41758)
  62. EP250908b: SVOM/VT optical candidate
  63. Fermi GRB 250909A: Global MASTER-Net observations report
  64. EP250908c: Einstein Probe detection of an X-ray transient
  65. EP250908b: EP-WXT detection of a fast X-ray transient and EP-FXT observation
  66. LIGO/Virgo/KAGRA S250908y: Identification of a GW compact binary merger candidate
  67. GRB 250907A: GECAM-B detection
  68. GRB 250905A: Swift-BAT refined analysis
  69. Fermi-LAT Gamma-ray Observations of IceCube-250905A
  70. GRB 250903A: Swift-XRT afterglow detection
  71. LIGO/Virgo/KAGRA S250906ca: Identification of a GW compact binary merger candidate
  72. IceCube-250905A: Upper limits from a search for additional neutrino events in IceCube
  73. SVOM/sb25090605: detection of an X-ray transient from the LMXB 4U 0513-40
  74. EP250905a: Liverpool Telescope i-band upper limits
  75. LIGO/Virgo/KAGRA S250830bp: DECam/SOAR GW-MMADS updates
  76. LIGO/Virgo/KAGRA S250830bp: DECam DESGW Epoch 2 Candidates
  77. EP250905a: Liverpool Telescope observations
  78. EP250905a: refined analysis of the EP-WXT and EP-FXT observations
  79. EP250905b: EP-WXT detection of a fast X-ray transient
  80. GRB 250905A: Swift-XRT refined Analysis
  81. EP250905a: JinShan likely optical counterpart detection
  82. GRB 250904A: Swift-BAT refined analysis
  83. GRB 250905A: Swift/UVOT Upper Limits
  84. GRB 250901A - SVOM/ECLAIRs refined analysis
  85. EP250905a: Einstein Probe detection of an X-ray transient
  86. GRB250904A: Liverpool Telescope upper limits
  87. GRB 250905A: Enhanced Swift-XRT position
  88. GRB 250904A: Swift/UVOT Detection
  89. GRB 250903A: Swift/UVOT detection
  90. GRB 250904A: Swift-XRT refined Analysis
  91. LIGO/Virgo/KAGRA S250904cv: Updated Sky localization
  92. LIGO/Virgo/KAGRA S250904br: Updated Sky localization
  93. EP detected a brightening of LMXB 1ES 1735-26.9
  94. GRB 250905A: KAIT optical upper limit
  95. GRB 250905A: Swift detection of a burst
  96. GRB 250904A: Enhanced Swift-XRT position
  97. IceCube-Cascade 250903A: Upper limits from a search for additional neutrino events in IceCube
  98. GRB 250904A: TRT optical counterpart detection
  99. EP250827a and EP250827b: Upper limit from Fermi-GBM Observations
  100. GRB 250904A: Swift detection of a burst

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