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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"

45700 results found.

  1. GRB 251125B: COLIBRÍ observations of fading of the MASTER OT candidate
  2. EP251124b: NOT r- and z-band optical upper limits
  3. Fermi GRB 251125B : MASTER OT J155558.56+581224.1 optical counterpart discovery
  4. Fermi GRB 251125B: Global MASTER-Net observations report
  5. GRB 251125B: Fermi GBM Final Real-time Localization
  6. EP251124b: Global MASTER-Net observations report
  7. EP251124b: EP-WXT detection of a fast X-ray transient
  8. EP251124a: Xinglong GWAC-F60A optical observation
  9. EP251124a (EP-WXT trigger 01709248862) is triggered by the known source AWM 7
  10. Fermi GRB 251125A: Global MASTER-Net observations report
  11. GRB 251125A: Fermi GBM Final Real-time Localization
  12. EP251124a: NOT r- and z-band optical upper limits
  13. EP251124a: Global MASTER-Net observations report
  14. EP251124a: Swift-XRT observations
  15. GRB 251124A: Fermi GBM Localization by automated pipeline
  16. LIGO/Virgo/KAGRA S251112cm: AT 2025adht Kinder follow-up observations
  17. EP251124a: Optical upper limit with Kinder observations
  18. GRB 251122B: Fermi GBM Final Localization
  19. EP251118A: 6 GHz VLA Detection
  20. Fermi GRB 251124a: Global MASTER-Net observations report
  21. GRB 251124a: Fermi GBM Final Localization
  22. LIGO/Virgo/KAGRA S251105aj: SVOM/VT optical observations and preliminary results on SVOM J2320.0-2901
  23. LIGO/Virgo/KAGRA S251105aj: EP-FXT follow-up observations and preliminary results on SVOM J2320.0-2901
  24. EP251124a: GROWTH-India Telescope optical upper limits
  25. EP251124a: Einstein Probe detection of an X-ray transient
  26. GRB 251116C: Swift-XRT confirmation of fading
  27. GRB 251122A/EP251122a: FTW optical and NIR observations
  28. GRB 251122A/EP251122A: 1.3m DFOT optical detection
  29. The EP-WXT trigger 01709248783 is likely a flaring star
  30. GRB 251122A / EP251122a: Xinglong 2.16m optical observation
  31. EP251118A: 3.6m DOT optical afterglow detection
  32. GRB 251122A / EP251122a: EP-FXT counterpart detection
  33. EP251122a: refined analysis of the EP-WXT and EP-FXT observations
  34. GRB 251122A / EP251122a: WFST optical observations
  35. GRB 251122A/EP251122a: SVOM/VT optical observations with VHF data
  36. GRB 251122A/EP251122a: Additional, deeper LCO optical r band upper limit
  37. GRB 251122A / EP251122a: LCO optical upper limits
  38. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  39. EP251122a: Global MASTER-Net observations report
  40. GRB 251122A/EP251122a: SVOM/C-GFT upper limit
  41. GRB 251122A / EP251122a: SVOM detection of a long burst
  42. EP251122a: Einstein Probe detection of an X-ray transient
  43. EP251118a: Continued Optical Detection with Kinder observations
  44. LIGO/Virgo/KAGRA S251105aj: SVOM/ECLAIRs detection of a high-energy transient SVOM J2320.0-2901 through targeted search
  45. LIGO/Virgo/KAGRA S251112cm: SOAR spectroscopy of three TROVE TNS candidates
  46. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  47. GRB 251121A: Glowbug gamma-ray detection of a likely short burst
  48. EP251118a: Xinglong-2.16m optical observation
  49. GRB 251115A: Fermi GBM Observation
  50. The EP-WXT trigger 01709248635 is likely a flaring star
  51. GRB 251121A: Fermi GBM Final Real-time Localization
  52. Fermi Gamma-ray Burst Monitor trigger 785388351 / 251121143 is not a GRB
  53. Fermi trigger No 785388351: Global MASTER-Net observations report
  54. EP251118A: 1.3m DFOT optical afterglow detection
  55. GRB 251118A: Swift/UVOT Detection
  56. EP251118a / GRB 251118C: SAO RAS optical observations
  57. GRB 251118A: Glowbug gamma-ray detection
  58. GRB 251118A: Fermi GBM Observation
  59. GRB 251118A: Swift-XRT afterglow detection
  60. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  61. EP251118a: Optical detection with Kinder observations
  62. GRB 251118A: GECAM-B detection
  63. EP-WXT trigger 01709248403: confirmation of a stellar flare by SVOM/VT
  64. LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
  65. EP251118a / GRB 251118C: SVOM/VT optical observation
  66. The EP-WXT trigger 01709248403 is likely a flaring star
  67. GRB 251118A: NuSTAR detection of bright prompt emission
  68. EP251118a / GRB 251118C: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at CTIO
  69. GRB 251116C: NOT optical observations
  70. GRB 251118C: Glowbug gamma-ray detection of the fast X-ray transient EP251118A
  71. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  72. GRB 251018A: FRAM-Auger optical detection
  73. GRB 251117A: Swift-XRT observations
  74. EP251118A / GRB 251118C : MASTER optical counterpart observations
  75. GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
  76. Konus-Wind detection of GRB 251118C (EP251118a)
  77. The EP-WXT trigger 01709248388 is likely a flaring star
  78. EP251118a: FTW optical and NIR observations
  79. GRB 251117A: Insight-HXMT/HE detection
  80. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  81. EP251118a: VLT near-infrared observation
  82. GRB 251116D: SVOM/GRM observation of a long GRB
  83. EP251118a: GOTO optical afterglow detection
  84. GRB 251119A: SVOM detection of a possible burst
  85. EP251118a: NOT spectroscopic redshift of z = 1.216
  86. EP251118a: Global MASTER-Net observations report
  87. EP251118a: preliminary result of EP-FXT follow-up observation
  88. LAT GRB251118.86: Global MASTER-Net observations report
  89. GRB 251118A: Fermi-LAT detection
  90. EP251118a: NOT candidate optical counterpart
  91. GRB 251118A: Swift ToO observations
  92. EP251118a: Einstein Probe detected of a fast X-ray transient
  93. Fermi GRB 251118B: Global MASTER-Net observations report
  94. GRB 251118B: Fermi GBM Final Real-time Localization
  95. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  96. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  97. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  98. GRB 251118A: Fermi GBM Final Real-time Localization
  99. GRB 251116C: SVOM/ECLAIRs refined analysis
  100. GRB 251116B: SVOM/ECLAIRs refined analysis

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