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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

16152 results found.

  1. X-ray transient EP240315a: orphan FXT?
  2. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  3. X-ray transient EP240315a: GROND J-band detection
  4. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  5. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  6. AT2024eju: followup observations with Liverpool Telescope suggest a fading transient
  7. X-ray transient EP240315a: ATLAS detection of a possible optical counterpart AT2024eju
  8. Einstein Probe detected of a fast X-ray transient EP240315a
  9. GRB240204A: VIRT optical upper limit
  10. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  11. Transient EPW20240219aa: Optical observations with LDT
  12. GRB 240225B: Swift-XRT afterglow detection
  13. GRB 240225B: further SAO RAS optical observations
  14. GRB 240225B: VLT/X-shooter redshift
  15. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  16. GRB 240225B: 3.6m DOT observation
  17. GRB 240225B: SAO RAS optical observations
  18. GRB 240225B: Mondy afterglow observations
  19. GRB 240225B: Liverpool Telescope afterglow observations
  20. Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
  21. GRB 240225B: Liverpool Telescope optical afterglow observations
  22. GRB 240225B: NOT optical observations
  23. GRB 240225B: Nanshan/HMT optical afterglow detection
  24. GRB 240225B: Swift-XRT observations
  25. GRB 240225B: GOTO detection of a candidate optical afterglow
  26. Transient EPW20240219aa: REM optical/NIR upper limits
  27. Transient EPW20240219aa: Xinglong-2.16m optical upper limit
  28. Transient EPW20240219aa: GECKO: LOAO Optical Upper Limits
  29. Transient EPW20240219aa: 7DT Optical Upper Limits
  30. Transient EPW20240219aa: Mondy optical observations
  31. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  32. GRB 240222A: Swift/UVOT Upper Limits
  33. GRB 240222A: REM optical and NIR early-time observations
  34. GRB 240218A: MeerLICHT upper limits
  35. IPN triangulation of GRB 240209A
  36. GRB 240218A: REM detection of a NIR afterglow candidate
  37. GRB 240209A: Classification of AT2024cew/GOTO24pw as Type Ia-pec supernova
  38. GRB 240209A: Fermi GBM observation
  39. GRB240209A: OHP/T193 detection of the GOTO afterglow candidate AT2024cew / GOTO24pw
  40. GRB 240209A: Wendelstein Optical Observations
  41. GRB 240209A: NOEMA non-detection of AT2024cew / GOTO24pw counterpart candidate
  42. GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
  43. GRB 240209A: GOTO optical counterpart candidate
  44. GRB 240205B: PRIME near infrared detection
  45. GRB240204A: Swift/UVOT Upper Limits
  46. GRB 240205B: VLT/X-shooter redshift
  47. GRB 240205B: BOOTES-6 optical afterglow follow-up
  48. GRB 240205B: REM detection of the optical/NIR afterglow
  49. GRB 240204A: Mondy optical afterglow observations
  50. GRB 240204A : OHP/T193/T120 optical afterglow fading detection
  51. GRB 240205B: Skynet Optical Afterglow Observations
  52. GRB 240205B: BOOTES-7 optical afterglow follow-up
  53. GRB 240204a: Liverpool Telescope optical afterglow detection
  54. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  55. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  56. GRB 240204A: Montarrenti Observatory optical observations
  57. GRB 240204A: Mondy optical afterglow candidate
  58. GRB240122A: PRIME near infrared detection
  59. GRB 240123A: further SAO RAS optical observations
  60. GRB 240123A: Mondy continued optical observations and the PL decay index
  61. GRB 240123A: SAO RAS optical observations
  62. GRB 240123A : MITSuME Akeno optical afterglow candidate detection
  63. GRB 240122A: Swift/UVOT Upper Limits
  64. GRB 240122A: BOOTES-2/TELMA optical upper limit and 1.5m OSN detection
  65. GRB 240123A: Mondy continued optical observations + correction of the GRB name in GCN 35605
  66. GRB 240118A: Swift/UVOT Upper Limits
  67. GRB 240123A: Mondy optical afterglow observations
  68. GRB 240123A: Swift detection of a burst with a possible optical counterpart
  69. GRB 240122A: Swift-XRT afterglow detection
  70. GRB 240122A: VLT/X-shooter redshift confirmation
  71. GRB 240122A: Redshift from OSIRIS+/GTC
  72. GRB 240122A: LT non-detection of GOTO candidate counterpart confirms fading
  73. GRB 240122A: GOTO optical counterpart candidate
  74. GRB 240118A: Mondy optical observations
  75. IceCube-240105A: Detection of NIR flare of PKS 0446+11 with WINTER
  76. GRB 240118A: AbAO optical upper limit
  77. IceCube-240105A: ZTF optical observation of blazar PKS 0446+11
  78. GRB 240112C: SAO RAS optical observations
  79. GRB 240112C: Swift detection of a burst with an optical counterpart
  80. GRB 240101A: 1.3m DFOT optical observations
  81. GRB 240102A: 1.3m DFOT optical upper limit
  82. GRB 240101B: 1.3m DFOT optical upper limit
  83. GRB 240102A: Swift/UVOT Upper Limits
  84. GRB 240102A: LCOGT Optical Upper Limits
  85. GRB240102A: BOOTES-6/DPRT optical upper limit
  86. GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  87. GRB 240101A: Terskol Zeiss-2000 optical observations
  88. GRB 240101B: Swift/UVOT Upper Limits
  89. GRB 240101A: Swift/UVOT Upper Limits
  90. GRB 240101B: KAIT Optical Upper Limit
  91. GRB 240101A: KAIT Optical Upper Limit
  92. GRB 231230A: GOTO optical upper limits
  93. GRB 231230A: Swift/UVOT Upper Limits
  94. GRB 231230A: NOT optical upper limits
  95. GRB 231210B: BOOTES-7 optical upper limit
  96. GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
  97. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
  98. GRB 231216A: optical upper limits from the INAF Asiago Observatory
  99. GRB 231216A: 10.4 m GTC optical upper limit
  100. GRB 231216A: Nanshan/HMT optical upper limit

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