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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"

43686 results found.

  1. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  2. LIGO/Virgo/KAGRA S251112cm: Classification of reported candidates with SOAR/Goodman
  3. GRB 251116B: SVOM/VT optical upper limit
  4. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  5. GRB 251116C: Swift-XRT observations
  6. LIGO/Virgo/KAGRA S251116en: Updated Sky localization
  7. GRB 251117A: Fermi GBM Final Localization Correction
  8. GRB 251116D: Glowbug gamma-ray detection
  9. EP251023a: Assy AZT-20 optical observations
  10. EP251023a: UAFO and AbAO optical observations
  11. GRB 251116D: AstroSat CZTI detection
  12. LIGO/Virgo/KAGRA S251112cm: EP-FXT follow-up observations
  13. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  14. GRB 251116C: SVOM/VT optical upper limit
  15. GRB 251025B: further Mondy optical observations
  16. GRB 251111A: Mondy optical upper limit
  17. GRB 251116B: EP-FXT follow-up observation
  18. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  19. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  20. GRB 251116B: LCO optical upper limits
  21. GRB 251116C: LCO optical upper limits
  22. SVOM GRB251116C: Global MASTER-Net observations report
  23. GRB 251116C: SVOM detection of a burst
  24. GRB 251116B: SVOM detection of a burst
  25. IceCube-Cascade 251112A: Upper limits from a search for additional neutrino events in IceCube
  26. GRB 251116A: Fermi GBM Final Real-time Localization
  27. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  28. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  29. GRB 251115A: Tiled Swift observations
  30. GRB 251115A: Fermi-LAT detection
  31. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  32. Fermi GRB 251115A: Global MASTER-Net observations report
  33. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  34. GRB 251115A: Fermi GBM Final Real-time Localization
  35. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  36. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  37. GRB 251113A: Glowbug gamma-ray detection
  38. GRB 251113A: AstroSat CZTI detection
  39. GRB 251114B: Fermi GBM Final Real-time Localization
  40. GRB 251112A: Swift-BAT refined analysis
  41. Konus-Wind detection of GRB 251108C
  42. Fermi trigger No 784717756: Global MASTER-Net observations report
  43. Konus-Wind detection of GRB 251103A
  44. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  45. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  46. IPN triangulation of GRB 251108C
  47. The EP-WXT trigger 01709248221 is likely a flaring star
  48. Fermi GRB 251114A: Global MASTER-Net observations report
  49. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  50. GRB 251114A: Fermi GBM Final Real-time Localization
  51. LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
  52. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  53. Fermi GRB 251113A: Global MASTER-Net observations report
  54. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  55. GRB 251113A: Fermi GBM Final Real-time Localization
  56. GRB 251111A: SVOM/ECLAIRs refined analysis
  57. GRB 251025B: SVOM/ECLAIRs refined analysis
  58. Fermi Gamma-ray Burst Monitor trigger 784717756/251113381 is not a GRB
  59. GRB 251112A: Swift/UVOT Upper Limits
  60. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  61. GRB 251112A: Swift-XRT refined Analysis
  62. GRB 251108C: AstroSat CZTI detection
  63. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  64. GRB 251112B: MAXI/GSC detection
  65. Fermi Gamma-ray Burst Monitor trigger 784687703/251113034 is not a GRB
  66. Fermi Gamma-ray Burst Monitor trigger 784687099/251113027 is not a GRB
  67. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  68. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  69. GRB 251108B: Glowbug gamma-ray detection
  70. Swift Trigger 1413695: a possible GRB 251112A
  71. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  72. Fermi trigger No 784621743: Global MASTER-Net observations report
  73. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 3-Initial Localization Volume
  74. Fermi Gamma-ray Burst Monitor trigger 784653403/251112637 is not a GRB
  75. GRB251111A: 1.3m DFOT optical upper limit
  76. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  77. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  78. GRB 251111A: Swift-XRT afterglow detection
  79. GRB 251111A: SVOM/VT optical observations with X-band data
  80. SVOM GRB251111.42: Global MASTER-Net observations report
  81. GRB 251111A: Swift-XRT observations
  82. SVOM GRB251111.22: Global MASTER-Net observations report
  83. GRB 251111A: EP-FXT counterpart detection
  84. GRB 251013C: Chandra X-ray observations and jet break detection
  85. GRB 251111A: SVOM/VT optical observations with VHF data
  86. GRB 251111A: KAIT optical upper limit
  87. GRB 251111A: LCO optical observation
  88. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  89. GRB 251111A: SVOM detection of a soft burst
  90. GRB 251103B: Swift-BAT refined analysis
  91. GRB 251105B: Insight-HXMT/HE detection
  92. GRB 251106B: Insight-HXMT detection
  93. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  94. GRB 251105A: AstroSat CZTI detection
  95. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  96. IceCube-Cascade 251107A: Upper limits from a search for additional neutrino events in IceCube
  97. LIGO/Virgo/KAGRA S251108fi: Updated Sky localization
  98. LIGO/Virgo/KAGRA S251108dn: Updated Sky localization
  99. GRB 251108A: Fermi GBM Final Localization Correction
  100. Fermi trigger No 784329591: Global MASTER-Net observations report

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