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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').
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"

32509 results found.

  1. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  2. GRB 241128A : RAPAS follow-up observations
  3. GRB 241201A: GRBAlpha detection
  4. EP241202b: Upper limits from Fermi-GBM Observations
  5. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  6. EP241202b: Kinder optical counterpart candidate
  7. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  8. GRB 241113B : RAPAS follow-up observation
  9. EP241201a: EP-FXT follow-up observations
  10. Konus-Wind detection of GRB 241130A
  11. EP241202b: Global MASTER-Net observations report
  12. EP241201a: BOOTES-5 optical upper limit
  13. EP241201a: NOT optical observations
  14. IPN triangulation of GRB 241130A
  15. GRB 241130A: EIRSAT-1 GMOD Detection
  16. GRB 241128A: Swift/UVOT Upper Limits
  17. IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube
  18. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  19. EP241201a: Kinder optical counterpart candidate
  20. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  21. EP241201a: Global MASTER-Net observations report
  22. LIGO/Virgo/KAGRA S241201ac: Updated Sky localization
  23. EP241126a: SOAR observations of the optical counterpart
  24. Fermi GRB 241201A: Global MASTER-Net observations report
  25. EP241126a: 1.6m Mephisto Optical Upper Limits
  26. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  27. LIGO/Virgo/KAGRA S241130be: Updated Sky localization
  28. IPN triangulation of GRB 241128B
  29. Konus-Wind detection of GRB 241114B
  30. LIGO/Virgo/KAGRA S241130n: Updated Sky localization
  31. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  32. GRB 241128A: AbAO optical upper limit
  33. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  34. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  35. LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
  36. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  37. GRB 241128A: Swift-BAT refined analysis
  38. GRB 241127A: Swift-BAT refined analysis
  39. EP241126a: NOT optical observations
  40. GRB 241127A: PRIME near-infrared detection
  41. GRB 241128A: Mondy optical observations
  42. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  43. Swift-XRT observations of IceCube -241127A
  44. Swift GRB 241128A: Global MASTER-Net observations report
  45. Fermi-LAT gamma-ray observations of IceCube-241127A
  46. EP241126a: SVOM/VT observations
  47. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  48. GRB 241128A: NOT optical observations
  49. GRB 241128A: LCO optical detection
  50. GRB 241128A: 1.5m OSN optical afterglow detection
  51. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  52. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  53. GRB 241127A: Swift/UVOT Detection
  54. GRB 241127A: SVOM/GRM observation
  55. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  56. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  57. EP241126a: WFST Observations
  58. LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
  59. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  60. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  61. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345)
  62. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345).
  63. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  64. EP241126a: Optical Upper limits with Kinder observations
  65. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  66. IPN triangulation of GRB 241114B
  67. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  68. EP241126a: EP-FXT follow-up observation update
  69. EP241126a: GSP detects optical counterpart
  70. EP241126a: TRT optical counterpart detection
  71. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  72. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  73. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  74. Trigger_18947: Swift ToO observations (retracted)
  75. GRB 241113B: EP-FXT afterglow detection
  76. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  77. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  78. SVOM/GRM detection of a short burst from SGR 1830
  79. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  80. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  81. Konus-Wind detection of GRB 241115D / EP 241115a
  82. LIGO/Virgo/KAGRA S241125n: HCT upper limit
  83. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  84. GRB 241026A: radio detection with the VLA
  85. EP241125a: Optical upper limit with Kinder observations
  86. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  87. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  88. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  89. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  90. LIGO/Virgo/KAGRA S241125n: Updated Sky localization
  91. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  92. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  93. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  94. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  95. GRB 241120A: GRBAlpha detection
  96. GRB 241113B: SVOM/VT optical afterglow observations
  97. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  98. Konus-Wind detection of GRB 241117A
  99. LIGO/Virgo/KAGRA S241122a: Updated Sky localization and Source Classification
  100. GRB 241105A: ATCA radio detection

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