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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"

28270 results found.

  1. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  2. GRB 251116C: Swift-XRT observations
  3. LIGO/Virgo/KAGRA S251116en: Updated Sky localization
  4. GRB 251116D: Glowbug gamma-ray detection
  5. EP251023a: Assy AZT-20 optical observations
  6. EP251023a: UAFO and AbAO optical observations
  7. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  8. GRB 251116C: SVOM/VT optical upper limit
  9. GRB 251025B: further Mondy optical observations
  10. GRB 251111A: Mondy optical upper limit
  11. GRB 251116B: EP-FXT follow-up observation
  12. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  13. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  14. GRB 251116B: LCO optical upper limits
  15. GRB 251116C: LCO optical upper limits
  16. SVOM GRB251116C: Global MASTER-Net observations report
  17. GRB 251116B: SVOM detection of a burst
  18. IceCube-Cascade 251112A: Upper limits from a search for additional neutrino events in IceCube
  19. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  20. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  21. Fermi GRB 251115A: Global MASTER-Net observations report
  22. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  23. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  24. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  25. GRB 251113A: Glowbug gamma-ray detection
  26. GRB 251112A: Swift-BAT refined analysis
  27. Fermi trigger No 784717756: Global MASTER-Net observations report
  28. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  29. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  30. Fermi GRB 251114A: Global MASTER-Net observations report
  31. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  32. Fermi GRB 251113A: Global MASTER-Net observations report
  33. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  34. GRB 251112A: Swift/UVOT Upper Limits
  35. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  36. GRB 251112A: Swift-XRT refined Analysis
  37. GRB 251112B: MAXI/GSC detection
  38. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  39. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  40. GRB 251108B: Glowbug gamma-ray detection
  41. Swift Trigger 1413695: a possible GRB 251112A
  42. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  43. Fermi trigger No 784621743: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 3-Initial Localization Volume
  45. GRB251111A: 1.3m DFOT optical upper limit
  46. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  47. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  48. GRB 251111A: Swift-XRT afterglow detection
  49. GRB 251111A: SVOM/VT optical observations with X-band data
  50. SVOM GRB251111.42: Global MASTER-Net observations report
  51. GRB 251111A: Swift-XRT observations
  52. SVOM GRB251111.22: Global MASTER-Net observations report
  53. GRB 251111A: EP-FXT counterpart detection
  54. GRB 251013C: Chandra X-ray observations and jet break detection
  55. GRB 251111A: SVOM/VT optical observations with VHF data
  56. GRB 251111A: LCO optical observation
  57. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  58. GRB 251103B: Swift-BAT refined analysis
  59. GRB 251106A: Swift/UVOT Upper Limits
  60. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  61. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  62. IceCube-Cascade 251107A: Upper limits from a search for additional neutrino events in IceCube
  63. LIGO/Virgo/KAGRA S251108fi: Updated Sky localization
  64. LIGO/Virgo/KAGRA S251108dn: Updated Sky localization
  65. Fermi trigger No 784329591: Global MASTER-Net observations report
  66. LIGO/Virgo/KAGRA S251108fi: Identification of a GW compact binary merger candidate
  67. Fermi trigger No 784279167: Global MASTER-Net observations report
  68. SVOM GRB251108.54: Global MASTER-Net observations report
  69. GRB 251102B: SVOM/GRM observation
  70. LIGO/Virgo/KAGRA S251108dn: Identification of a GW compact binary merger candidate
  71. SVOM GRB251106.83: Global MASTER-Net observations report
  72. LIGO/Virgo/KAGRA S251105aj: Updated Sky localization
  73. LIGO/Virgo/KAGRA S251103f: Updated Sky localization
  74. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
  75. GRB 251106A: Swift-XRT afterglow detection
  76. GRB 251106A: Kilonova-Catcher optical upper limit
  77. Fermi GBM Sub-Threshold Detection of GRB 251106A
  78. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  79. GRB 251106A: MASTER optical observations
  80. GRB 251025C: TERI Gamma-ray detection
  81. GRB 251016B: TERI Gamma-ray detection
  82. GRB 251016A: TERI Gamma-ray detection of a short burst
  83. GRB 250920C: TERI Gamma-ray detection
  84. Fermi trigger No 784034269: Global MASTER-Net observations report
  85. EP251102a: Xinglong 2.16-m clear-band observations of the optical counterpart
  86. GRB 251105A: Fermi GBM Observation
  87. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  88. GRB 251104A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  89. Fermi GBM Sub-Threshold Detection of GRB 251105B
  90. GRB 251103B: Swift/UVOT Upper Limits
  91. LIGO/Virgo/KAGRA S251105aj: Identification of a GW compact binary merger candidate
  92. GRB 251103B: Fermi GBM observation
  93. GRB 251103A: WFST optical observations
  94. GRB 251103A: OHP/T193 optical observations
  95. GRB 251103A: Xinglong 2.16m optical detection
  96. GRB 251103A: KAIT optical observations
  97. GRB 251103B: Nanshan/HMT optical upper limit
  98. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  99. GRB 251103A: Swift/BAT-GUANO arcminute localization of a burst
  100. GRB 251103B: MITSuME Akeno optical upper limits

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