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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"

26560 results found.

  1. GRB 250916A: KAIT optical observations
  2. GRB 250917B: VLT/HAWK-I near-infrared observations
  3. GRB 250916A: further SAO RAS optical observations
  4. GRB 250912A: SVOM/ECLAIRs refined analysis
  5. LIGO/Virgo/KAGRA S250918aw: 1 counterpart neutrino candidate event from an IceCube neutrino search
  6. GRB 250918A: BALROG localization (Fermi Trigger 779891543 / GRB 250918522)
  7. GRB 250917B: Swift/UVOT Upper Limits
  8. GRB 250916A: OSIRIS+/GTC redshift z = 2.015
  9. GRB 250916A: Swift-XRT observations
  10. EP250916a: EP-FXT follow-up observation
  11. GRB 250916A: MAO/AZT-22 optical observations
  12. GRB 250916A: SAO RAS optical observations
  13. GRB 250916A : GIT optical observations
  14. LIGO/Virgo/KAGRA S250917aq: Three counterpart neutrino candidates from IceCube neutrino searches
  15. GRB 250916A: Glowbug gamma-ray detection
  16. GRB250917B: WFST optical observations
  17. GRB 250917B: Fermi GBM Observation
  18. GRB 250917B: Swift-XRT observations
  19. LIGO/Virgo/KAGRA S250917aq: Identification of a GW compact binary merger candidate
  20. GRB 250917B: Swift detection of a short burst
  21. The EP-WXT trigger 01709241037 is likely a flaring star
  22. GRB 250916A: AstroSat CZTI detection of a bright long burst
  23. GRB 250910A: SVOM/ECLAIRs refined analysis
  24. EP250916a: Einstein Probe detection of an X-ray transient
  25. SVOM/sb25091517: SVOM detection of an X-ray transient
  26. GRB 250912A: Swift/BAT-GUANO localization skymap of a possibly short burst
  27. GRB 250912A: SVOM/COLIBRÍ (FM-GFT) optical observations
  28. GRB 250912A: Swift-XRT observations
  29. GRB250912A: VLT/HAWK-I follow-up observations
  30. GRB 250912A: Fermi GBM Observation
  31. GRB 250912A: SVOM/GRM analysis suggests a possible short GRB with extended emission
  32. GRB 250912A:SVOM/VT optical upper limit
  33. GRB 250912A: LCO optical upper limit
  34. The EP-WXT trigger 01709240768 is likely a flaring star
  35. GRB 250912A: SVOM detection of a burst
  36. IceCube-Cascade 250911A: Upper limits from a search for additional neutrino events in IceCube
  37. LIGO/Virgo/KAGRA S250912s: 2 counterpart neutrino candidate events from an IceCube neutrino search
  38. GRB 250911A: GECAM-B detection
  39. LIGO/Virgo/KAGRA S250912f: Identification of a GW compact binary merger candidate
  40. EP250911a: refined analysis of the EP-WXT and EP-FXT observations
  41. GRB 250910B: SVOM/GRM observation
  42. EP250911a: SVOM/VT optical observation
  43. GRB 250911A: MASTER optical counterpart observations
  44. EP250911a: SAO RAS optical observations
  45. GRB 250911A: Swift-XRT refined Analysis
  46. EP250911a: Swift-XRT observations
  47. EP250911a: Optical detection with Kinder observations
  48. GRB 250911A: Swift/UVOT Detection
  49. GRB 250910A / EP250910a: Swift-XRT afterglow detection
  50. GRB 250910A / EP250910a: SVOM/VT afterglow confirmation
  51. GRB 250910A / EP250910a : VLT/HAWK-I NIR counterpart discovery
  52. EP250911a: COLIBRÍ optical observations
  53. EP250911a: Einstein Probe detection of an X-ray transient
  54. LIGO/Virgo/KAGRA S250911ac: Identification of a GW compact binary merger candidate
  55. GRB 250903A: SVOM/ECLAIRs refined analysis
  56. GRB 250911A: Enhanced Swift-XRT position
  57. GRB 250911A: Swift-XRT observations
  58. GRB 250911A: COLIBRÍ optical counterpart candidate
  59. GRB 250910A / EP250910a: VLT/HAWK-I near-infrared observations
  60. EP250910a/GRB 250910A: EP-WXT detection of a fast X-ray transient
  61. GRB 250910A: SVOM/VT optical upper limit
  62. GRB 250910A: LCO optical upper limit
  63. GRB 250910A: SVOM detection of a faint burst
  64. GRB 250702B: Late time Chandra observations
  65. EP250908b/EP#01709240653: Swift/UVOT Detection
  66. EP#01709240653: Swift-XRT observations
  67. The EP-WXT trigger 01709240674 is triggered by the known source SS Cyg
  68. EP250908c: refined analysis of the EP-WXT and EP-FXT observations
  69. EP250908c: SVOM/VT optical observation
  70. EP250908c: VLT/FORS2 optical counterpart identification
  71. EP250908b: SVOM/VT optical candidate (Coordinate supplement for GCN 41758)
  72. EP250908b: SVOM/VT optical candidate
  73. EP250908c: Einstein Probe detection of an X-ray transient
  74. EP250908b: EP-WXT detection of a fast X-ray transient and EP-FXT observation
  75. LIGO/Virgo/KAGRA S250908y: Identification of a GW compact binary merger candidate
  76. GRB 250907A: GECAM-B detection
  77. Fermi-LAT Gamma-ray Observations of IceCube-250905A
  78. GRB 250903A: Swift-XRT afterglow detection
  79. LIGO/Virgo/KAGRA S250906ca: Identification of a GW compact binary merger candidate
  80. IceCube-250905A: Upper limits from a search for additional neutrino events in IceCube
  81. SVOM/sb25090605: detection of an X-ray transient from the LMXB 4U 0513-40
  82. EP250905a: Liverpool Telescope i-band upper limits
  83. LIGO/Virgo/KAGRA S250830bp: DECam/SOAR GW-MMADS updates
  84. EP250905b: EP-FXT follow-up observation
  85. LIGO/Virgo/KAGRA S250830bp: DECam DESGW Epoch 2 Candidates
  86. EP250905a: Liverpool Telescope observations
  87. EP250905a: refined analysis of the EP-WXT and EP-FXT observations
  88. EP250905b: EP-WXT detection of a fast X-ray transient
  89. GRB 250905A: Swift-XRT refined Analysis
  90. EP250905a: JinShan likely optical counterpart detection
  91. GRB 250905A: Swift/UVOT Upper Limits
  92. GRB 250901A - SVOM/ECLAIRs refined analysis
  93. EP250905a: Einstein Probe detection of an X-ray transient
  94. GRB250904A: Liverpool Telescope upper limits
  95. GRB 250905A: Enhanced Swift-XRT position
  96. GRB 250904A: Swift/UVOT Detection
  97. GRB 250903A: Swift/UVOT detection
  98. GRB 250904A: Swift-XRT refined Analysis
  99. EP detected a brightening of LMXB 1ES 1735-26.9
  100. GRB 250905A: KAIT optical upper limit

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