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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"

16159 results found.

  1. GRB 241209A: GRANDMA/TAROT upper limit
  2. GRB 241209B: BOOTES-5 optical upper limit
  3. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
  4. GRB 241209A: REM optical/NIR observations
  5. GRB 241209D: Swift detection of a burst
  6. GRB 241209A: VLT optical observations
  7. GRB 241209A: GOTO optical upper limits
  8. EP241206a: 1.5m OSN optical limit
  9. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  10. EP241206a: BOOTES Global Network optical limits
  11. GRB 241207C: MASTER optical observations
  12. GRB 241206B: GWAC-F50A optical upper limit
  13. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  14. EP241201a: 1.6m Mephisto Optical Upper Limits
  15. GRB 241204A: COLIBRÍ Optical Upper Limit
  16. EP241202b: KAIT optical upper limit
  17. EP241202b: Kinder optical counterpart candidate
  18. EP241201a: BOOTES-5 optical upper limit
  19. EP241201a: NOT optical observations
  20. GRB 241128A: Swift/UVOT Upper Limits
  21. EP241201a: Kinder optical counterpart candidate
  22. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  23. EP241126a: SOAR observations of the optical counterpart
  24. EP241126a: 1.6m Mephisto Optical Upper Limits
  25. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  26. GRB 241128A: AbAO optical upper limit
  27. EP241126a: NOT optical observations
  28. GRB 241127A: PRIME near-infrared detection
  29. GRB 241128A: Mondy optical observations
  30. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  31. Swift-XRT observations of IceCube -241127A
  32. EP241126a: SVOM/VT observations
  33. GRB 241128A: NOT optical observations
  34. GRB 241128A: LCO optical detection
  35. GRB 241128A: 1.5m OSN optical afterglow detection
  36. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  37. GRB 241127A: Swift/UVOT Detection
  38. GRB 241127A: SVOM/GRM observation
  39. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  40. Swift GRB241127.91: Global MASTER-Net OT detection
  41. EP241126a: WFST Observations
  42. GRB 241127A: Swift detection of a burst with an optical counterpart
  43. Swift GRB241127.91: Global MASTER-Net OT detection
  44. EP241126a: Optical Upper limits with Kinder observations
  45. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  46. EP241126a: EP-FXT follow-up observation update
  47. EP241126a: GSP detects optical counterpart
  48. EP241126a: TRT optical counterpart detection
  49. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  50. GRB 241113B: EP-FXT afterglow detection
  51. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  52. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  53. SVOM/GRM detection of a short burst from SGR 1830
  54. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  55. GRB 241026A: radio detection with the VLA
  56. EP241125a: Optical upper limit with Kinder observations
  57. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  58. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  59. GRB 241113B: SVOM/VT optical afterglow observations
  60. GRB 241105A: ATCA radio detection
  61. GRB 241026A: VIRT Optical Upper Limit
  62. GRB 241025A: VIRT Optical Upper Limit
  63. GRB241120A: OHP/T193 optical observations
  64. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  65. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  66. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  67. GRB 241120A: Mondy and AbAO optical observations
  68. EP241119a: Optical upper limits with Kinder observations
  69. EP241119a: GIT optical upper limits
  70. GRB 241113A: Possible ATCA Radio detection
  71. GRB 241112B: Mephisto further optical observations
  72. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  73. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  74. GRB 241115A: Mephisto upper limits
  75. GRB 241113B: Mephisto upper limits
  76. GRB 241115D / EP 241115a: SVOM/GRM observation
  77. GRB 241115A: LCOGT Optical Upper Limits
  78. EP 241113a: LBT possible optical counterpart
  79. GRB 241113B: KAIT Optical Afterglow Candidate
  80. GRB 241113A: J-band observations with WINTER
  81. GRB 241030A: LCO optical observation
  82. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  83. GRB 241113A: KAIT optical observations
  84. GRB 241113B: SVOM/GRM observation
  85. EP241107a: SOAR upper limits
  86. GRB 241113A: REM detection of the optical/NIR afterglow
  87. GRB 241113A: LCO optical observations
  88. GRB 241112B: GMG Optical Upper Limit
  89. GRB241113A: LCOGT (40-cm) optical counterpart detection
  90. GRB 241113A: MASTER010615.66-224018.2 optical counterpart detection
  91. GRB 241113A: Swift detection of a burst with an optical counterpart
  92. SVOM/GRM detection of a short burst from SGR 1E1841-045
  93. GRB 241105A: ATCA Radio Upper Limits
  94. GRB 241112B: AbAO optical upper limit
  95. GRB 241107A: GROWTH-India telescope optical upper limit
  96. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  97. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  98. GRB 241112B: SVOM/GRM observation
  99. GRB 241112B: SVOM/VT afterglow detection
  100. GRB 241112B: Mephisto optical upper limits

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