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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"

41969 results found.

  1. GRB 250916A: SAO RAS optical observations
  2. GRB 250916A : GIT optical observations
  3. LIGO/Virgo/KAGRA S250917aq: Three counterpart neutrino candidates from IceCube neutrino searches
  4. GRB 250916A: Glowbug gamma-ray detection
  5. GRB250917B: WFST optical observations
  6. GRB 250916A: Swift ToO observations
  7. GRB 250917B: Fermi GBM Observation
  8. GRB 250917B: Swift-XRT observations
  9. LIGO/Virgo/KAGRA S250917aq: Identification of a GW compact binary merger candidate
  10. Fermi GRB 250917B: Global MASTER-Net observations report
  11. GRB 250917B: Swift detection of a short burst
  12. GRB 250916A: GOTO optical counterpart candidate
  13. GRB 250917B: Fermi GBM Final Real-time Localization
  14. GRB 250917A: Fermi GBM Final Real-time Localization
  15. The EP-WXT trigger 01709241037 is likely a flaring star
  16. GRB 250916A: AstroSat CZTI detection of a bright long burst
  17. GRB 250910A: SVOM/ECLAIRs refined analysis
  18. EP250916a: Einstein Probe detection of an X-ray transient
  19. Fermi GRB 250916A: Global MASTER-Net observations report
  20. GRB 250916A: Fermi GBM Final Real-time Localization
  21. EP250827b: VLA Observations
  22. LIGO/Virgo/KAGRA S250818k: HCT optical follow-up
  23. SVOM/sb25091517: Confirmation of a stellar flare by SVOM/VT
  24. SVOM/sb25091517: FRAM-ORM stellar flare - transient observation
  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: VLT observations
  31. GRB 250912A: Fermi GBM Observation
  32. GRB 250911A: Insight-HXMT detection
  33. GRB 250912A: SVOM/GRM analysis suggests a possible short GRB with extended emission
  34. GRB 250912A:SVOM/VT optical upper limit
  35. GRB 250912A: LCO optical upper limit
  36. The EP-WXT trigger 01709240768 is likely a flaring star
  37. Fermi GRB 250912A: Global MASTER-Net observations report
  38. EP250911a: Global MASTER-Net observations report
  39. GRB 250912A: SVOM detection of a burst
  40. GRB 250912A: Fermi GBM Final Real-time Localization
  41. IceCube-Cascade 250911A: Upper limits from a search for additional neutrino events in IceCube
  42. LIGO/Virgo/KAGRA S250912s: 2 counterpart neutrino candidate events from an IceCube neutrino search
  43. EP250908c: tentative VLT/FORS2 redshift z = 2.87
  44. EP250911a: Upper limit from Fermi-GBM Observations
  45. GRB 250911A: GECAM-B detection
  46. GRB 250911A: Swift-BAT refined analysis
  47. EP250911a: GTC/OSIRIS+ spectroscopic redshift z = 3.84
  48. LIGO/Virgo/KAGRA S250912f: Identification of a GW compact binary merger candidate
  49. EP250911a: refined analysis of the EP-WXT and EP-FXT observations
  50. GRB 250910B: SVOM/GRM observation
  51. EP250911a: SVOM/VT optical observation
  52. GRB 250911A: MASTER optical counterpart observations
  53. EP250911a: SAO RAS optical observations
  54. GRB 250911A: Swift-XRT refined Analysis
  55. GRB 250910C: Fermi GBM Final Localization Correction
  56. EP250911a: Swift-XRT observations
  57. EP250911a: Optical detection with Kinder observations
  58. GRB 250911A: Swift/UVOT Detection
  59. GRB 250910A / EP250910a: Swift-XRT afterglow detection
  60. GRB 250910A / EP250910a: SVOM/VT afterglow confirmation
  61. GRB 250909B: Insight-HXMT detection
  62. GRB 250909B: SVOM/GRM observation
  63. GRB 250910A / EP250910a : VLT/HAWK-I NIR counterpart discovery
  64. EP250911a: COLIBRÍ optical observations
  65. Fermi GRB 250910B: Global MASTER-Net observations report
  66. EP250911a: LCO optical counterpart discovery
  67. EP250910a: Global MASTER-Net observations report
  68. EP250911a: Einstein Probe detection of an X-ray transient
  69. GRB 250404A / EP250404a: spectroscopic redshift at z = 1.88 (correction to GCN 40084)
  70. LIGO/Virgo/KAGRA S250911ac: Identification of a GW compact binary merger candidate
  71. GRB 250903A: SVOM/ECLAIRs refined analysis
  72. GRB 250911A: Enhanced Swift-XRT position
  73. GRB 250911A: Swift-XRT observations
  74. GRB 250911A: COLIBRÍ optical counterpart candidate
  75. GRB 250911A: Swift detection of a burst
  76. GRB 250910B: BALROG localization (Fermi Trigger 779223130 / GRB 250910786)
  77. GRB 250910B: Fermi GBM Final Real-time Localization
  78. GRB 250910A / EP250910a: VLT/HAWK-I near-infrared observations
  79. EP250910a/GRB 250910A: EP-WXT detection of a fast X-ray transient
  80. GRB 250909B: AstroSat CZTI detection of a long burst
  81. GRB 250910A: SVOM/VT optical upper limit
  82. EP250908C: GROND observation of the fading optical counterpart
  83. GRB 250910A: LCO optical upper limit
  84. GRB 250909A: AstroSat CZTI detection
  85. GRB 250910A: SVOM/MXT possible afterglow detection
  86. GRB 250910A: SVOM detection of a faint burst
  87. LIGO/Virgo/KAGRA S250910b: Retraction of GW compact binary merger candidate
  88. GRB 250702B: Late time Chandra observations
  89. EP250908b/EP#01709240653: Swift/UVOT Detection
  90. EP#01709240653: Swift-XRT observations
  91. The EP-WXT trigger 01709240674 is triggered by the known source SS Cyg
  92. EP250908c: refined analysis of the EP-WXT and EP-FXT observations
  93. GRB 250907A: CALET Gamma-Ray Burst Monitor detection
  94. EP250908c: SVOM/VT optical observation
  95. EP250908c: VLT/FORS2 optical counterpart identification
  96. EP250908b: SVOM/VT optical candidate (Coordinate supplement for GCN 41758)
  97. EP250908b: SVOM/VT optical candidate
  98. EP250908c: Global MASTER-Net observations report
  99. Fermi GRB 250909A: Global MASTER-Net observations report
  100. EP250908c: Einstein Probe detection of an X-ray transient

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