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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"

32770 results found.

  1. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  2. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  3. GRB 251115A: Tiled Swift observations
  4. GRB 251115A: Fermi-LAT detection
  5. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  6. Fermi GRB 251115A: Global MASTER-Net observations report
  7. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  8. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  9. GRB 251113A: Glowbug gamma-ray detection
  10. GRB 251113A: AstroSat CZTI detection
  11. GRB 251112A: Swift-BAT refined analysis
  12. Konus-Wind detection of GRB 251108C
  13. Konus-Wind detection of GRB 251103A
  14. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  15. IPN triangulation of GRB 251108C
  16. Fermi GRB 251114A: Global MASTER-Net observations report
  17. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  18. LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
  19. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  20. Fermi GRB 251113A: Global MASTER-Net observations report
  21. GRB 251111A: SVOM/ECLAIRs refined analysis
  22. GRB 251025B: SVOM/ECLAIRs refined analysis
  23. GRB 251112A: Swift/UVOT Upper Limits
  24. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  25. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  26. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  27. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  28. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  29. GRB251111A: 1.3m DFOT optical upper limit
  30. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  31. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  32. GRB 251111A: SVOM/VT optical observations with X-band data
  33. GRB 251111A: Swift-XRT observations
  34. GRB 251111A: EP-FXT counterpart detection
  35. GRB 251013C: Chandra X-ray observations and jet break detection
  36. GRB 251111A: SVOM/VT optical observations with VHF data
  37. GRB 251111A: KAIT optical upper limit
  38. GRB 251111A: LCO optical observation
  39. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  40. GRB 251103B: Swift-BAT refined analysis
  41. GRB 251106A: Swift/UVOT Upper Limits
  42. GRB 251105B: Insight-HXMT/HE detection
  43. GRB 251106B: Insight-HXMT detection
  44. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  45. GRB 251105A: AstroSat CZTI detection
  46. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  47. LIGO/Virgo/KAGRA S251108fi: Updated Sky localization
  48. LIGO/Virgo/KAGRA S251108dn: Updated Sky localization
  49. LIGO/Virgo/KAGRA S251108fi: Identification of a GW compact binary merger candidate
  50. GRB 251102B: SVOM/GRM observation
  51. LIGO/Virgo/KAGRA S251108dn: Identification of a GW compact binary merger candidate
  52. LIGO/Virgo/KAGRA S251105aj: Updated Sky localization
  53. LIGO/Virgo/KAGRA S251103f: Updated Sky localization
  54. IPN triangulation of GRB 251105B (possible sGRB with EE)
  55. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
  56. GRB 251106A: Swift-XRT afterglow detection
  57. GRB 251106A: Kilonova-Catcher optical upper limit
  58. Fermi GBM Sub-Threshold Detection of GRB 251106A
  59. GRB 251106A: Swift/BAT arcminute localization of a burst
  60. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  61. GRB 251106A: MASTER optical observations
  62. GRB 251103B: AstroSat CZTI detection
  63. GRB 251025C: TERI Gamma-ray detection
  64. GRB 251016B: TERI Gamma-ray detection
  65. GRB 251016A: TERI Gamma-ray detection of a short burst
  66. GRB 250920C: TERI Gamma-ray detection
  67. EP251102a: Xinglong 2.16-m clear-band observations of the optical counterpart
  68. GRB 251105A: Fermi GBM Observation
  69. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  70. GRB 251104A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  71. GRB 251105B: AstroSat CZTI detection of a short burst with extended emission
  72. GRB 251023A: SVOM/ECLAIRs detection of a burst through targeted search
  73. Fermi GBM Sub-Threshold Detection of GRB 251105B
  74. GRB 251103B: Swift/UVOT Upper Limits
  75. LIGO/Virgo/KAGRA S251105aj: Identification of a GW compact binary merger candidate
  76. Fermi GRB 251105A: Global MASTER-Net observations report
  77. GRB 251103B: Fermi GBM observation
  78. GRB 251028A: Insight-HXMT/HE detection
  79. GRB 251103A: Optical afterglow detection by ZTF’s public survey
  80. EP251102a: FTW optical and NIR observations
  81. GRB 251103A: WFST optical observations
  82. EP251102a: update of EP-FXT follow-up observation
  83. EP251102a: OHP/T193 optical observations
  84. GRB 251103A: OHP/T193 optical observations
  85. GRB 251103A: Xinglong 2.16m optical detection
  86. GRB 251103A: Insight-HXMT detection
  87. GRB 251103A: KAIT optical observations
  88. GRB 251103B: Nanshan/HMT optical upper limit
  89. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  90. GRB 251103B: MITSuME Akeno optical upper limits
  91. Fermi GRB 251103A: Global MASTER-Net observations report
  92. LIGO/Virgo/KAGRA S251103f: Identification of a GW compact binary merger candidate
  93. EP251102a: NIR observations with WINTER
  94. GRB 251103A: J-band detection with WINTER
  95. Swift GRB 251103B: Global MASTER-Net observations report
  96. GRB 251103B: GROWTH-India Telescope optical upper limits
  97. GRB 251103A: Kilonova-Catcher optical afterglow detection
  98. GRB 251103A: Swift/UVOT Detection
  99. GRB 251103A: Fermi GBM Observation
  100. GRB 251103A: SVOM/GRM observation

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