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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"

22237 results found.

  1. GRB 251122A/EP251122a: SVOM/VT optical observations with VHF data
  2. GRB 251122A / EP251122a: LCO optical upper limits
  3. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  4. EP251122a: Global MASTER-Net observations report
  5. GRB 251122A/EP251122a: SVOM/C-GFT upper limit
  6. EP251118a: Continued Optical Detection with Kinder observations
  7. LIGO/Virgo/KAGRA S251105aj: SVOM/ECLAIRs detection of a high-energy transient SVOM J2320.0-2901 through targeted search
  8. LIGO/Virgo/KAGRA S251112cm: SOAR spectroscopy of three TROVE TNS candidates
  9. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  10. EP251118a: Xinglong-2.16m optical observation
  11. Fermi trigger No 785388351: Global MASTER-Net observations report
  12. EP251118A: 1.3m DFOT optical afterglow detection
  13. GRB 251118A: Swift/UVOT Detection
  14. EP251118a / GRB 251118C: SAO RAS optical observations
  15. GRB 251118A: Swift-XRT afterglow detection
  16. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  17. EP251118a: Optical detection with Kinder observations
  18. LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
  19. EP251118a / GRB 251118C: SVOM/VT optical observation
  20. EP251118a / GRB 251118C: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at CTIO
  21. GRB 251116C: NOT optical observations
  22. GRB 251117A: Swift-XRT observations
  23. EP251118A / GRB 251118C : MASTER optical counterpart observations
  24. EP251118a: FTW optical and NIR observations
  25. EP251118a: VLT near-infrared observation
  26. EP251118a: GOTO optical afterglow detection
  27. GRB 251119A: SVOM detection of a possible burst
  28. EP251118a: Global MASTER-Net observations report
  29. LAT GRB251118.86: Global MASTER-Net observations report
  30. EP251118a: NOT candidate optical counterpart
  31. GRB 251118A: Swift ToO observations
  32. EP251118a: Einstein Probe detected of a fast X-ray transient
  33. Fermi GRB 251118B: Global MASTER-Net observations report
  34. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  35. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  36. GRB 251116C: SVOM/ECLAIRs refined analysis
  37. GRB 251116B: SVOM/ECLAIRs refined analysis
  38. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  39. GRB 251115A: Swift-XRT observations
  40. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  41. GRB 251117A: Tiled Swift observations
  42. LAT GRB251117.51: Global MASTER-Net observations report
  43. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  44. LIGO/Virgo/KAGRA S251112cm: Classification of reported candidates with SOAR/Goodman
  45. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  46. GRB 251116C: Swift-XRT observations
  47. EP251023a: Assy AZT-20 optical observations
  48. EP251023a: UAFO and AbAO optical observations
  49. LIGO/Virgo/KAGRA S251112cm: EP-FXT follow-up observations
  50. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  51. GRB 251025B: further Mondy optical observations
  52. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  53. SVOM GRB251116C: Global MASTER-Net observations report
  54. GRB 251116B: SVOM detection of a burst
  55. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  56. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  57. GRB 251115A: Tiled Swift observations
  58. Fermi GRB 251115A: Global MASTER-Net observations report
  59. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  60. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  61. Konus-Wind detection of GRB 251108C
  62. Fermi trigger No 784717756: Global MASTER-Net observations report
  63. Konus-Wind detection of GRB 251103A
  64. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  65. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  66. Fermi GRB 251114A: Global MASTER-Net observations report
  67. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  68. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  69. Fermi GRB 251113A: Global MASTER-Net observations report
  70. GRB 251111A: SVOM/ECLAIRs refined analysis
  71. GRB 251025B: SVOM/ECLAIRs refined analysis
  72. GRB 251112A: Swift/UVOT Upper Limits
  73. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  74. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  75. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  76. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  77. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  78. Fermi trigger No 784621743: Global MASTER-Net observations report
  79. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 3-Initial Localization Volume
  80. GRB251111A: 1.3m DFOT optical upper limit
  81. GRB 251111A: Swift-XRT afterglow detection
  82. GRB 251111A: SVOM/VT optical observations with X-band data
  83. SVOM GRB251111.42: Global MASTER-Net observations report
  84. GRB 251111A: Swift-XRT observations
  85. SVOM GRB251111.22: Global MASTER-Net observations report
  86. GRB 251013C: Chandra X-ray observations and jet break detection
  87. GRB 251111A: SVOM/VT optical observations with VHF data
  88. GRB 251111A: KAIT optical upper limit
  89. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  90. GRB 251106A: Swift/UVOT Upper Limits
  91. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  92. Fermi trigger No 784329591: Global MASTER-Net observations report
  93. Fermi trigger No 784279167: Global MASTER-Net observations report
  94. SVOM GRB251108.54: Global MASTER-Net observations report
  95. SVOM GRB251106.83: Global MASTER-Net observations report
  96. GRB 251106A: Swift-XRT afterglow detection
  97. GRB 251106A: Kilonova-Catcher optical upper limit
  98. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  99. GRB 251106A: MASTER optical observations
  100. Fermi trigger No 784034269: Global MASTER-Net observations report

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