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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"

45622 results found.

  1. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  2. GRB 251118A: Fermi GBM Final Real-time Localization
  3. GRB 251116C: SVOM/ECLAIRs refined analysis
  4. GRB 251116B: SVOM/ECLAIRs refined analysis
  5. GRB 251117A: AstroSat CZTI detection
  6. GRB 251114B: Insight-HXMT/HE detection
  7. GRB 251114B: GECAM-B detection of a short burst
  8. GRB 251117A: Fermi GBM observation
  9. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  10. LIGO/Virgo/KAGRA S251117dq: Updated Sky localization
  11. GRB 251116D: Insight-HXMT/HE detection
  12. GRB 251115A: Swift-XRT observations
  13. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  14. GRB 251117A: SVOM/GRM observation of a short burst
  15. GRB 251117A: Tiled Swift observations
  16. GRB 251117A: Fermi-LAT detection
  17. LAT GRB251117.51: Global MASTER-Net observations report
  18. LIGO/Virgo/KAGRA S251117dq: Identification of a GW compact binary merger candidate
  19. GRB 251116C: Swift/BAT arcminute localization of a burst
  20. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  21. LIGO/Virgo/KAGRA S251112cm: Classification of reported candidates with SOAR/Goodman
  22. GRB 251116B: SVOM/VT optical upper limit
  23. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  24. GRB 251116C: Swift-XRT observations
  25. LIGO/Virgo/KAGRA S251116en: Updated Sky localization
  26. GRB 251117A: Fermi GBM Final Localization Correction
  27. GRB 251116D: Glowbug gamma-ray detection
  28. EP251023a: Assy AZT-20 optical observations
  29. EP251023a: UAFO and AbAO optical observations
  30. GRB 251116D: AstroSat CZTI detection
  31. LIGO/Virgo/KAGRA S251112cm: EP-FXT follow-up observations
  32. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  33. GRB 251116C: SVOM/VT optical upper limit
  34. GRB 251025B: further Mondy optical observations
  35. GRB 251111A: Mondy optical upper limit
  36. GRB 251116B: EP-FXT follow-up observation
  37. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  38. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  39. GRB 251116B: LCO optical upper limits
  40. GRB 251116C: LCO optical upper limits
  41. SVOM GRB251116C: Global MASTER-Net observations report
  42. GRB 251116C: SVOM detection of a burst
  43. GRB 251116B: SVOM detection of a burst
  44. IceCube-Cascade 251112A: Upper limits from a search for additional neutrino events in IceCube
  45. GRB 251116A: Fermi GBM Final Real-time Localization
  46. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  47. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  48. GRB 251115A: Tiled Swift observations
  49. GRB 251115A: Fermi-LAT detection
  50. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  51. Fermi GRB 251115A: Global MASTER-Net observations report
  52. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  53. GRB 251115A: Fermi GBM Final Real-time Localization
  54. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  55. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  56. GRB 251113A: Glowbug gamma-ray detection
  57. GRB 251113A: AstroSat CZTI detection
  58. GRB 251114B: Fermi GBM Final Real-time Localization
  59. GRB 251112A: Swift-BAT refined analysis
  60. Konus-Wind detection of GRB 251108C
  61. Fermi trigger No 784717756: Global MASTER-Net observations report
  62. Konus-Wind detection of GRB 251103A
  63. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  64. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  65. IPN triangulation of GRB 251108C
  66. The EP-WXT trigger 01709248221 is likely a flaring star
  67. Fermi GRB 251114A: Global MASTER-Net observations report
  68. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  69. GRB 251114A: Fermi GBM Final Real-time Localization
  70. LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
  71. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  72. Fermi GRB 251113A: Global MASTER-Net observations report
  73. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  74. GRB 251113A: Fermi GBM Final Real-time Localization
  75. GRB 251111A: SVOM/ECLAIRs refined analysis
  76. GRB 251025B: SVOM/ECLAIRs refined analysis
  77. Fermi Gamma-ray Burst Monitor trigger 784717756/251113381 is not a GRB
  78. GRB 251112A: Swift/UVOT Upper Limits
  79. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  80. GRB 251112A: Swift-XRT refined Analysis
  81. GRB 251108C: AstroSat CZTI detection
  82. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  83. GRB 251112B: MAXI/GSC detection
  84. Fermi Gamma-ray Burst Monitor trigger 784687703/251113034 is not a GRB
  85. Fermi Gamma-ray Burst Monitor trigger 784687099/251113027 is not a GRB
  86. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  87. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  88. GRB 251108B: Glowbug gamma-ray detection
  89. Swift Trigger 1413695: a possible GRB 251112A
  90. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  91. Fermi trigger No 784621743: Global MASTER-Net observations report
  92. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 3-Initial Localization Volume
  93. Fermi Gamma-ray Burst Monitor trigger 784653403/251112637 is not a GRB
  94. GRB251111A: 1.3m DFOT optical upper limit
  95. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  96. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  97. GRB 251111A: Swift-XRT afterglow detection
  98. GRB 251111A: SVOM/VT optical observations with X-band data
  99. SVOM GRB251111.42: Global MASTER-Net observations report
  100. GRB 251111A: Swift-XRT observations

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