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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"

16189 results found.

  1. EP 240416a: Xinglong and NOT decaying optical counterpart
  2. EP240416A: MASTER optical observations
  3. EP240416a: Kinder optical counterpart candidate
  4. GRB 240414A: AbAO optical upprer limit
  5. GRB 240415A: Swift/UVOT Detection
  6. EP240413a: BOOTES-2/TELMA Optical Upper Limit
  7. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  8. GRB 240415A: Earliest optical followup with the Kinder observations
  9. EP 240414a: BOOTES-4/MET Optical Upper Limits
  10. EP240414a: EP-FXT follow-up observation
  11. GRB 240415A: OHP/T193 optical observations
  12. GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
  13. GRB 240415A: SAO RAS optical observations
  14. GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
  15. GRB 240415A: Mondy optical transient detection
  16. GRB 240414A: Photometric observation from 2.2m CAHA
  17. GRB 240414A: Swift/UVOT Detection
  18. LXT 240402A/GRB 240402B: Swift follow-up observations
  19. GRB 240414A: Mondy optical observations
  20. GRB 240414A: AKO Optical Upper Limit
  21. EP 240414a: NOT optical counterpart confirmation
  22. GRB240414A : J-band upper limits from WINTER
  23. GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
  24. GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  25. LIGO/Virgo/KAGRA S240413p: No Counterparts in DDOTI/OAN Optical Observations
  26. EP240413A: GOTO optical upper limits
  27. GRB 240414A: Skynet Optical Afterglow Observations
  28. EP240414a: Kinder optical counterpart candidate possibly associated with the galaxy SDSS J124601.99-094309.3
  29. GRB 240414A : MITSuME Akeno optical upper limits
  30. GRB 240414A : OHP/T193 redshift determination
  31. GRB 240414A : OHP/T193 optical counterpart detection
  32. EP240408a: GSP optical upper limit
  33. GRB 240411B: CrAO/ZTSh optical observations
  34. GRB 240411B: Kinder observations with Lulin observatory
  35. GRB 240411B: 1.3m DFOT Optical observations
  36. GRB 240411B: OHP/T193 optical observations
  37. GRB 240411B: LCO optical afterglow detection
  38. EP240408A: MASTER optical observations
  39. EP240408a: GROND detection of a candidate counterpart
  40. EP240408a: BOOTES-6/DPRT optical upper limit
  41. X-ray transient EP240315a: second epoch e-MERLIN radio observations
  42. IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits
  43. X-ray transient LXT 240402A: WFST optical upper limits​
  44. GRB/FXT 240402B: Kinder optical counterpart candidate
  45. IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
  46. GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
  47. X-ray transient LXT240402A: AST3-3 optical upper limits
  48. LXT 240402A: MASTER optical observations with AGN in error-box
  49. GRB 240402B: GWAC-F50A optical upper limit
  50. X-ray transient EP240331a: Kinder optical upper limits
  51. X-ray transient EP240331A: GRANDMA-Kilonova catcher optical upper limit
  52. EP240331A: MASTER optical observations
  53. Transient EP240315a: J-band observations of AT2024eju with WIRC
  54. X-ray transient EP20240331a: MeerLICHT optical upper limits
  55. X-ray transient EP240315a: continued ATCA monitoring
  56. X-ray transient EP240315a: e-MERLIN radio observations
  57. X-ray transient EP240315a: Ondrejov D50 optical limit
  58. Transient EPW20240219aa: REM optical/NIR further observations
  59. X-ray transient EP240315a: ATCA detection of radio counterpart
  60. X-ray transient EP240315a: GTC/HiPERCAM photometry
  61. X-ray transient EP240315a: MeerKAT radio detection
  62. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  63. X-ray transient EP240315a: PRIME near infrared detection
  64. X-ray transient EP240315a: 3.6 m TNG NIR detection
  65. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  66. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  67. X-ray transient EP240315a: Kitab observatory optical upper limitns
  68. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  69. X-ray transient EP240315a: orphan FXT?
  70. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  71. X-ray transient EP240315a: GROND J-band detection
  72. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  73. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  74. AT2024eju: followup observations with Liverpool Telescope suggest a fading transient
  75. X-ray transient EP240315a: ATLAS detection of a possible optical counterpart AT2024eju
  76. Einstein Probe detected of a fast X-ray transient EP240315a
  77. GRB240204A: VIRT optical upper limit
  78. Transient EPW20240219aa: Optical observations with LDT
  79. GRB 240225B: Swift-XRT afterglow detection
  80. GRB 240225B: further SAO RAS optical observations
  81. GRB 240225B: VLT/X-shooter redshift
  82. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  83. GRB 240225B: 3.6m DOT observation
  84. GRB 240225B: SAO RAS optical observations
  85. GRB 240225B: Mondy afterglow observations
  86. GRB 240225B: Liverpool Telescope afterglow observations
  87. Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
  88. GRB 240225B: Liverpool Telescope optical afterglow observations
  89. GRB 240225B: NOT optical observations
  90. GRB 240225B: Nanshan/HMT optical afterglow detection
  91. GRB 240225B: Swift-XRT observations
  92. GRB 240225B: GOTO detection of a candidate optical afterglow
  93. Transient EPW20240219aa: REM optical/NIR upper limits
  94. Transient EPW20240219aa: Xinglong-2.16m optical upper limit
  95. Transient EPW20240219aa: GECKO: LOAO Optical Upper Limits
  96. Transient EPW20240219aa: 7DT Optical Upper Limits
  97. Transient EPW20240219aa: Mondy optical observations
  98. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  99. GRB 240222A: Swift/UVOT Upper Limits
  100. GRB 240222A: REM optical and NIR early-time observations

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