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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"

38683 results found.

  1. LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
  2. EP251118a / GRB 251118C: SVOM/VT optical observation
  3. The EP-WXT trigger 01709248403 is likely a flaring star
  4. GRB 251118A: NuSTAR detection of bright prompt emission
  5. EP251118a / GRB 251118C: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at CTIO
  6. GRB 251116C: NOT optical observations
  7. GRB 251118C: Glowbug gamma-ray detection of the fast X-ray transient EP251118A
  8. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  9. GRB 251117A: Swift-XRT observations
  10. GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
  11. Konus-Wind detection of GRB 251118C (EP251118a)
  12. The EP-WXT trigger 01709248388 is likely a flaring star
  13. GRB 251117A: Insight-HXMT/HE detection
  14. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  15. EP251118a: VLT near-infrared observation
  16. GRB 251116D: SVOM/GRM observation of a long GRB
  17. EP251118a: GOTO optical afterglow detection
  18. GRB 251119A: SVOM detection of a possible burst
  19. EP251118a: NOT spectroscopic redshift of z = 1.216
  20. EP251118a: preliminary result of EP-FXT follow-up observation
  21. GRB 251118A: Fermi-LAT detection
  22. EP251118a: NOT candidate optical counterpart
  23. GRB 251118A: Swift ToO observations
  24. EP251118a: Einstein Probe detected of a fast X-ray transient
  25. GRB 251118B: Fermi GBM Final Real-time Localization
  26. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  27. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  28. GRB 251118A: Fermi GBM Final Real-time Localization
  29. GRB 251116C: SVOM/ECLAIRs refined analysis
  30. GRB 251116B: SVOM/ECLAIRs refined analysis
  31. GRB 251117A: AstroSat CZTI detection
  32. GRB 251114B: Insight-HXMT/HE detection
  33. GRB 251114B: GECAM-B detection of a short burst
  34. GRB 251117A: Fermi GBM observation
  35. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  36. GRB 251116D: Insight-HXMT/HE detection
  37. GRB 251115A: Swift-XRT observations
  38. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  39. GRB 251117A: SVOM/GRM observation of a short burst
  40. GRB 251117A: Tiled Swift observations
  41. GRB 251117A: Fermi-LAT detection
  42. GRB 251116C: Swift/BAT arcminute localization of a burst
  43. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  44. LIGO/Virgo/KAGRA S251112cm: Classification of reported candidates with SOAR/Goodman
  45. GRB 251116B: SVOM/VT optical upper limit
  46. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  47. GRB 251116C: Swift-XRT observations
  48. GRB 251117A: Fermi GBM Final Localization Correction
  49. GRB 251116D: Glowbug gamma-ray detection
  50. EP251023a: Assy AZT-20 optical observations
  51. EP251023a: UAFO and AbAO optical observations
  52. GRB 251116D: AstroSat CZTI detection
  53. LIGO/Virgo/KAGRA S251112cm: EP-FXT follow-up observations
  54. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  55. GRB 251116C: SVOM/VT optical upper limit
  56. GRB 251025B: further Mondy optical observations
  57. GRB 251111A: Mondy optical upper limit
  58. GRB 251116B: EP-FXT follow-up observation
  59. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  60. GRB 251116B: LCO optical upper limits
  61. GRB 251116C: LCO optical upper limits
  62. SVOM GRB251116C: Global MASTER-Net observations report
  63. GRB 251116C: SVOM detection of a burst
  64. GRB 251116B: SVOM detection of a burst
  65. IceCube-Cascade 251112A: Upper limits from a search for additional neutrino events in IceCube
  66. GRB 251116A: Fermi GBM Final Real-time Localization
  67. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  68. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  69. GRB 251115A: Tiled Swift observations
  70. GRB 251115A: Fermi-LAT detection
  71. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  72. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  73. GRB 251115A: Fermi GBM Final Real-time Localization
  74. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  75. GRB 251113A: Glowbug gamma-ray detection
  76. GRB 251113A: AstroSat CZTI detection
  77. GRB 251114B: Fermi GBM Final Real-time Localization
  78. Konus-Wind detection of GRB 251108C
  79. Konus-Wind detection of GRB 251103A
  80. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  81. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  82. IPN triangulation of GRB 251108C
  83. The EP-WXT trigger 01709248221 is likely a flaring star
  84. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  85. GRB 251114A: Fermi GBM Final Real-time Localization
  86. LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
  87. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  88. GRB 251113A: Fermi GBM Final Real-time Localization
  89. GRB 251111A: SVOM/ECLAIRs refined analysis
  90. GRB 251025B: SVOM/ECLAIRs refined analysis
  91. Fermi Gamma-ray Burst Monitor trigger 784717756/251113381 is not a GRB
  92. GRB 251112A: Swift/UVOT Upper Limits
  93. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  94. GRB 251112A: Swift-XRT refined Analysis
  95. GRB 251108C: AstroSat CZTI detection
  96. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  97. GRB 251112B: MAXI/GSC detection
  98. Fermi Gamma-ray Burst Monitor trigger 784687703/251113034 is not a GRB
  99. Fermi Gamma-ray Burst Monitor trigger 784687099/251113027 is not a GRB
  100. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations

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