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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"

32489 results found.

  1. EP241201a: Global MASTER-Net observations report
  2. LIGO/Virgo/KAGRA S241201ac: Updated Sky localization
  3. EP241126a: SOAR observations of the optical counterpart
  4. Fermi GRB 241201A: Global MASTER-Net observations report
  5. EP241126a: 1.6m Mephisto Optical Upper Limits
  6. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  7. LIGO/Virgo/KAGRA S241130be: Updated Sky localization
  8. IPN triangulation of GRB 241128B
  9. Konus-Wind detection of GRB 241114B
  10. LIGO/Virgo/KAGRA S241130n: Updated Sky localization
  11. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  12. GRB 241128A: AbAO optical upper limit
  13. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  14. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  15. LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
  16. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  17. GRB 241128A: Swift-BAT refined analysis
  18. GRB 241127A: Swift-BAT refined analysis
  19. EP241126a: NOT optical observations
  20. GRB 241127A: PRIME near-infrared detection
  21. GRB 241128A: Mondy optical observations
  22. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  23. Swift-XRT observations of IceCube -241127A
  24. Swift GRB 241128A: Global MASTER-Net observations report
  25. Fermi-LAT gamma-ray observations of IceCube-241127A
  26. EP241126a: SVOM/VT observations
  27. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  28. GRB 241128A: NOT optical observations
  29. GRB 241128A: LCO optical detection
  30. GRB 241128A: 1.5m OSN optical afterglow detection
  31. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  32. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  33. GRB 241127A: Swift/UVOT Detection
  34. GRB 241127A: SVOM/GRM observation
  35. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  36. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  37. EP241126a: WFST Observations
  38. LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
  39. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  40. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  41. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345)
  42. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345).
  43. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  44. EP241126a: Optical Upper limits with Kinder observations
  45. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  46. IPN triangulation of GRB 241114B
  47. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  48. EP241126a: EP-FXT follow-up observation update
  49. EP241126a: GSP detects optical counterpart
  50. EP241126a: TRT optical counterpart detection
  51. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  52. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  53. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  54. Trigger_18947: Swift ToO observations (retracted)
  55. GRB 241113B: EP-FXT afterglow detection
  56. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  57. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  58. SVOM/GRM detection of a short burst from SGR 1830
  59. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  60. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  61. Konus-Wind detection of GRB 241115D / EP 241115a
  62. LIGO/Virgo/KAGRA S241125n: HCT upper limit
  63. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  64. GRB 241026A: radio detection with the VLA
  65. EP241125a: Optical upper limit with Kinder observations
  66. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  67. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  68. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  69. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  70. LIGO/Virgo/KAGRA S241125n: Updated Sky localization
  71. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  72. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  73. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  74. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  75. GRB 241120A: GRBAlpha detection
  76. GRB 241113B: SVOM/VT optical afterglow observations
  77. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  78. Konus-Wind detection of GRB 241117A
  79. LIGO/Virgo/KAGRA S241122a: Updated Sky localization and Source Classification
  80. GRB 241105A: ATCA radio detection
  81. LIGO/Virgo/KAGRA S241122a: Identification of a GW compact binary merger candidate
  82. IPN triangulation of GRB 241117A
  83. GRB 241026A: VIRT Optical Upper Limit
  84. GRB 241025A: VIRT Optical Upper Limit
  85. Konus-Wind detection of GRB 241120A
  86. GRB241120A: OHP/T193 optical observations
  87. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  88. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  89. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  90. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  91. GRB 241120A: Mondy and AbAO optical observations
  92. EP241119a: Optical upper limits with Kinder observations
  93. EP241119a: GIT optical upper limits
  94. GRB 241113A: Possible ATCA Radio detection
  95. EP241119a : J-band observations with WINTER
  96. GRB 241120A: Fermi GBM Observation
  97. EP241119a: Global MASTER-Net observations report
  98. GRB241120A: a long GRB detected by INTEGRAL
  99. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  100. GRB 241112B: Mephisto further optical observations

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