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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"

32492 results found.

  1. GRB 241213A: LCOGT Optical Upper Limits
  2. EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
  3. EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
  4. GRB 241213A: REM optical/NIR upper limits
  5. GRB241212A: OHP/T193 optical observations
  6. GRB 241213A: SAO RAS optical upper limit
  7. LIGO/Virgo/KAGRA S241210fu: Updated Sky localization
  8. Swift GRB 241213A: Global MASTER-Net observations report
  9. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  10. GRB 241212A : SVOM/VT bright optical afterglow
  11. GRB 241212A: AstroSat CZTI detection
  12. GRB 241209B: GRANDMA/TRT upper limit
  13. GRB 241207A: TSHAO Zeiss-1000 optical observations
  14. GRB 241212A: SVOM detection of a bright long burst
  15. GRB 241209B: Mondy AZT-33IK and AbAO AS-32 optical observations
  16. GRB 241209A: Chandra X-ray Detection
  17. Konus-Wind detection of GRB 241209B
  18. GRB 241207A: EIRSAT-1 GMOD Detection
  19. GRB 241209A: Redshift of the likely host galaxy z = 0.784 from OSIRIS+/GTC
  20. GRB 241209B: GRBAlpha detection
  21. GRB 241206C: GRBAlpha detection
  22. LIGO/Virgo/KAGRA S241210cw: Updated Sky localization
  23. LIGO/Virgo/KAGRA S241210d: Updated Sky localization and EM Bright Classification
  24. GRB 241129A: Fermi GBM Observation
  25. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  26. GRB 241209D: REM optical/NIR upper limits
  27. Konus-Wind detection of GRB 241209D
  28. GRB 241209B: Swift-XRT afterglow detection
  29. GRB 241209C: Fermi GBM Observation
  30. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  31. EP241208a: Optical upper limit with Kinder observations
  32. GRB 241128A: CrAO ZTSh and Mondy AZT-33IK optical observations
  33. GRB 241209D: AstroSat CZTI detection
  34. GRB 241209A: EP-FXT follow-up observations
  35. GRB 241209B: SVOM/VT afterglow detection
  36. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  37. EP241208a: Global MASTER-Net observations report
  38. EP241208a: EP-FXT follow-up observations
  39. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  40. GRB 241207B: Fermi GBM Observation
  41. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  42. GRB 241209D: Fermi GBM Observation
  43. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  44. GRB 241209D: COLIBRÍ detection of the afterglow
  45. GRB 241209A: COLIBRÍ Optical Upper Limit
  46. Fermi GRB 241209D: Global MASTER-Net observations report
  47. GRB 241209A: Fermi GBM Observation
  48. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  49. GRB 241209A: GRANDMA/TAROT upper limit
  50. GRB 241209B: BOOTES-5 optical upper limit
  51. Swift GRB 241209D: Global MASTER-Net observations report
  52. Fermi GRB 241209C: Global MASTER-Net observations report
  53. Fermi GRB 241209E: Global MASTER-Net observations report
  54. GRB 241209B: Swift ToO observations
  55. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
  56. GRB 241209A: REM optical/NIR observations
  57. GRB 241209C: AstroSat CZTI detection
  58. GRB 241209A: VLT/X-shooter spectroscopy
  59. GRB 241114B: cubesat Avion detection
  60. GRB 241209A: VLT optical observations
  61. Fermi GRB 241209A: Global MASTER-Net observations report
  62. GRB 241209A: GOTO optical upper limits
  63. Fermi GRB 241207B: Global MASTER-Net observations report
  64. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  65. GRB 241201A: AstroSat CZTI detection
  66. GRB 241206A: DDOTI Upper Limit on the Afterglow
  67. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  68. GRB 241207C: MASTER optical observations
  69. GRB 241207C: Tiled Swift observations
  70. Fermi GRB 241207A: Global MASTER-Net observations report
  71. EP241206a: Global MASTER-Net observations report
  72. GRB 241206A: Fermi GBM observation
  73. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  74. GRB 241206B: SVOM/MXT observations: a probable flare from the QSO 1ES 1959+650
  75. GRB 241206B: GWAC-F50A optical upper limit
  76. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  77. Fermi GRB 241206A: Global MASTER-Net observations report
  78. EP241201a: 1.6m Mephisto Optical Upper Limits
  79. GRB 241204A: COLIBRÍ Optical Upper Limit
  80. EP241202b: KAIT optical upper limit
  81. GRB 241204A: DDOTI Upper Limits on the Afterglow
  82. GRB 241204A: Fermi GBM Observation
  83. Fermi GRB 241204A: Global MASTER-Net observations report
  84. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  85. GRB 241128A : RAPAS follow-up observations
  86. GRB 241201A: GRBAlpha detection
  87. EP241202b: Upper limits from Fermi-GBM Observations
  88. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  89. EP241202b: Kinder optical counterpart candidate
  90. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  91. GRB 241113B : RAPAS follow-up observation
  92. EP241201a: EP-FXT follow-up observations
  93. Konus-Wind detection of GRB 241130A
  94. EP241202b: Global MASTER-Net observations report
  95. EP241201a: BOOTES-5 optical upper limit
  96. EP241201a: NOT optical observations
  97. IPN triangulation of GRB 241130A
  98. GRB 241130A: EIRSAT-1 GMOD Detection
  99. GRB 241128A: Swift/UVOT Upper Limits
  100. IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube

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