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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"

24633 results found.

  1. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  2. GRB 241207B: Fermi GBM Observation
  3. GRB 241209D: Swift-XRT refined Analysis
  4. GRB 241209D: Fermi GBM Observation
  5. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  6. GRB 241209D: COLIBRÍ detection of the afterglow
  7. GRB 241209A: COLIBRÍ Optical Upper Limit
  8. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  9. GRB 241209A: GRANDMA/TAROT upper limit
  10. GRB 241209A: REM optical/NIR observations
  11. GRB 241209D: Enhanced Swift-XRT position
  12. GRB 241209D: Swift detection of a burst
  13. GRB 241209A: Enhanced Swift-XRT position
  14. GRB 241114B: cubesat Avion detection
  15. GRB 241209A: VLT optical observations
  16. GRB 241209A: GOTO optical upper limits
  17. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  18. EP241208a: EP detection of a fast X-ray transient
  19. GRB 241209A: Swift detection of a short burst
  20. Fermi GRB 241207B: Global MASTER-Net observations report
  21. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  22. GRB 241206A: DDOTI Upper Limit on the Afterglow
  23. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  24. GRB 241207C: MAXI/GSC detection
  25. EP241206a: EP detection of a fast X-ray transient
  26. GRB 241206A: Fermi GBM observation
  27. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  28. EP241201a: 1.6m Mephisto Optical Upper Limits
  29. GRB 241204A: COLIBRÍ Optical Upper Limit
  30. EP241202b: KAIT optical upper limit
  31. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  32. GRB 241204A: DDOTI Upper Limits on the Afterglow
  33. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  34. GRB 241128A : RAPAS follow-up observations
  35. EP241202b: Upper limits from Fermi-GBM Observations
  36. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  37. EP241202b: Kinder optical counterpart candidate
  38. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  39. GRB 241113B : RAPAS follow-up observation
  40. Konus-Wind detection of GRB 241130A
  41. EP241201a: BOOTES-5 optical upper limit
  42. EP241202b: EP detection of a fast X-ray transient
  43. EP241201a: NOT optical observations
  44. IPN triangulation of GRB 241130A
  45. GRB 241130A: EIRSAT-1 GMOD Detection
  46. GRB 241128A: Swift/UVOT Upper Limits
  47. GRB 241130A: Fermi GBM Detection
  48. IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube
  49. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  50. EP241201a: Kinder optical counterpart candidate
  51. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  52. LIGO/Virgo/KAGRA S241201ac: Updated Sky localization
  53. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  54. EP241126a: 1.6m Mephisto Optical Upper Limits
  55. GRB 241201A: Fermi GBM Final Real-time Localization
  56. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  57. LIGO/Virgo/KAGRA S241130be: Updated Sky localization
  58. Fermi trigger No 754701230: Global MASTER-Net observations report
  59. LIGO/Virgo/KAGRA S241130n: Updated Sky localization
  60. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  61. GRB 241128A: AbAO optical upper limit
  62. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  63. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  64. LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
  65. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  66. GRB 241128A: Swift-BAT refined analysis
  67. GRB 241127A: Swift-BAT refined analysis
  68. GRB 241127A: PRIME near-infrared detection
  69. GRB 241128A: Mondy optical observations
  70. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  71. Swift-XRT observations of IceCube -241127A
  72. Fermi-LAT gamma-ray observations of IceCube-241127A
  73. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  74. GRB 241128A: Swift-XRT refined Analysis
  75. GRB 241128A: Enhanced Swift-XRT position
  76. GRB 241128A: NOT optical observations
  77. GRB 241128A: LCO optical detection
  78. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  79. GRB 241128A: Swift-XRT afterglow detection
  80. GRB 241128A: Swift detection of a burst
  81. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  82. GRB 241127A: Swift/UVOT Detection
  83. GRB 241127A: Swift-XRT refined Analysis
  84. GRB 241127A: Enhanced Swift-XRT position
  85. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  86. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  87. Swift GRB241127.91: Global MASTER-Net OT detection
  88. EP241126a: WFST Observations
  89. LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
  90. GRB 241127A: Swift detection of a burst with an optical counterpart
  91. Swift GRB241127.91: Global MASTER-Net OT detection
  92. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  93. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  94. LIGO/Virgo/KAGRA S241127aj: NED Galaxies in the Localization Volume
  95. EP241126a: Optical Upper limits with Kinder observations
  96. IPN triangulation of GRB 241114B
  97. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  98. EP241126a: GSP detects optical counterpart
  99. EP241126a: TRT optical counterpart detection
  100. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate

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