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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

219 results found.

  1. GRB 260802A / EP J223759.5+531421: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  2. AT2026nik: EP-FXT X-ray counterpart
  3. GRB 260204A: Swift-XRT observations
  4. GRB 251208D: Swift-XRT observations
  5. GRB 251203B: Swift-XRT observations
  6. EP251130a: Swift-XRT counterpart detection
  7. GRB 251116C: Swift-XRT observations
  8. GRB 251111A: Swift-XRT observations
  9. GRB 251027A: Swift-XRT observations
  10. GRB 251026A: Swift-XRT observations
  11. EP#01709247298: Swift-XRT counterpart detection
  12. sb25101602: Swift-XRT counterpart detection
  13. GRB 251013C: Swift-XRT counterpart detection
  14. EP250911a: Swift-XRT observations
  15. EP#01709240653: Swift-XRT observations
  16. GRB 250903A: Swift-XRT observations
  17. EP250903a: Swift-XRT observations
  18. EP250827a: Swift-XRT counterpart detection
  19. EP250821a: Swift XRT and UVOT counterpart detection
  20. GRB 250808A: Swift-XRT candidate counterpart detection
  21. GRB 250727A: Swift-XRT observations
  22. GRB 250713A: Swift-XRT observations
  23. EP#01709178975: Swift-XRT counterpart detection
  24. sb25061218: Swift-XRT observations
  25. sb25061207: Swift-XRT observations
  26. GRB 250610B: Swift-XRT counterpart detection
  27. GRB 250530A: Swift-XRT counterpart detection
  28. EP#01709176612: Swift-XRT counterpart detection of flaring star
  29. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  30. XMM-Newton observation of EP240426a
  31. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  32. GRB 231115A: XMM-Newton observation
  33. GRB 211106A: XMM-Newton monitoring campaign detections
  34. IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
  35. Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
  36. GRB 200415A: MASTER imspection and possible localisation
  37. Further Swift-XRT observations of Swift J0840.7-3516
  38. LIGO/Virgo S200115j: Further Swift-XRT sources
  39. GRB 191031D: XMM-Newton upper limit
  40. IceCube-190221A: Swift-XRT Follow-up Observations
  41. CORRECTED TARGET NAME: GRB 190114C: Planned XMM-Newton observation
  42. GRB 150114C#: Planned XMM-Newton observation
  43. IceCube-190104A: Swift-XRT observations
  44. Trigger 809217: Swift trigger on RS CVn Star HD 8357
  45. GW170817/GRB170817A: Preliminary results of Chandra monitoring
  46. LIGO/Virgo GW170817: Chandra X-ray Emission Continues to Rise ~156 Days Post-Merger
  47. LIGO/Virgo G299232/GW170825: serendipitous XMM-Newton slew observations
  48. LIGO/Virgo G298936/GW170823: serendipitous XMM-Newton slew observations
  49. IceCube-170922A: Swift-XRT observations
  50. LIGO/Virgo G297595: Swift-XRT sources
  51. GRB170714A: XMM observation of the afterglow
  52. LIGO/Virgo G275697: Further Swift-XRT sources
  53. LIGO/Virgo G275697: Further Swift-XRT sources
  54. LIGO/Virgo G275697: Further Swift-XRT sources
  55. LIGO/Virgo G275697: Swift-XRT sources
  56. LIGO/Virgo G268556: Swift-XRT detection of ATLAS17aeu
  57. Trigger 706396: Swift detection of a short burst from PSR 1119-6127
  58. LIGO/Virgo G211117/GW151226: serendipitous XMM-Newton slew observations
  59. LIGO/Virgo G211117: Further Swift-XRT sources
  60. GRB151127A: Planned XMM-Newton observation
  61. LIGO/Virgo G184098: Swift follow-up observations
  62. GRB 150818A: Planned XMM-Newton observation
  63. Trigger 649113: Swift detection of SGR 1E 1841-045
  64. Trigger 639199: Swift detection of IGRJ16418-4532
  65. Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
  66. Swift J0045.2+4151: analysis of XMM-Newton archival data
  67. Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
  68. BAT trigger 633105 (GRB 150301C): NOT r-band upper limit
  69. Trigger 633105 (aka GRB150301C): Swift/UVOT Observations of XRT Counterpart
  70. GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
  71. GRB 150101B/Swift J123205.1-105602: XMM-Newton observation
  72. The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
  73. Swift detection of the variable star SZ Psc
  74. Swift detection of UX Ari
  75. Swift detection of a bright X-ray source in M31
  76. Swift trigger 599860 probably not real
  77. Swift Trigger 596958 is probably the flare star: DG CVn
  78. GRB 131202A : XMM-Newton planned observation
  79. GRB 130821A: Swift-XRT observation
  80. GRB 130603B: First epoch of XMM-Newton observations
  81. Planned XMM-Newton and IRAM observation of GRB 121011A
  82. GRB 120804A: Late-time Chandra observation
  83. XMM observations of the short GRB120804A
  84. Trigger 530588: Swift detection of XMM J174457-2850.3
  85. GRB120711A: Planned XMM-Newton observation
  86. Swift triggers (#524542) on a Galactic source
  87. XMM-Newton observation of the short GRB 111020A
  88. GRB 111209A: GROND Afterglow observations
  89. GRB111209A : planned XMM-Newton observation
  90. GRB 111020A: Planned XMM-Newton observation
  91. SGR J1834.9-0846: A Neutron Star in W41?
  92. GRB 110807A: Swift detection of a burst or a posible new SGR
  93. SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
  94. GRB 100909A: Planned XMM-Newton observation
  95. GRB 100614 : XMM-Newton observation
  96. Swift UVOT and UVOT-enhanced XRT position for GRB 100528A
  97. Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
  98. GRB 090618: planned XMM-Newton observation
  99. Trigger 330353: Swift detection of a Galactic short soft burst
  100. SGR 0501+4516: preliminary results of the Suzaku ToO observation

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