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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"

16218 results found.

  1. EP240919a: EP-WXT detection of a fast X-ray transient
  2. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  3. EP240918a: EP observation update
  4. GRB 240910A: further Swift observations and confirmation of afterglow
  5. EP240918a: JinShan optical upper limits
  6. EP240918a: Optical upper limits with Kinder observations
  7. EP240918a: GMG Optical Upper Limit
  8. EP240918a: an X-ray transient detected by Einstein Probe
  9. IPN triangulation of GRB 240913C / EP 240913a
  10. GRB 240821A: radio observation with the VLA
  11. GRB 240916A: Swift-XRT afterglow detection
  12. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  13. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  14. EP240913a: VLT/HAWK-I near-infrared upper limits
  15. GRB 240914A: Swift-XRT observations
  16. GRB 240914B: AstroSat CZTI detection
  17. GRB 240910A: SVOM/VT optical observations
  18. EP240913a: NOT optical upper limits
  19. EP240913a: JinShan optical upper limits
  20. EP240913a: ESO-NTT optical observations
  21. GRB 240914A: ESO-NTT optical observations
  22. GRB 240905E: further NOT optical observations
  23. EP240913a: EP-WXT detection of a fast X-ray transient
  24. GRB 240911A: LCO optical observations
  25. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  26. GRB 240912A: Swift/UVOT Detection
  27. GRB 240912A: J-band observations with WINTER
  28. GRB 240912A: Swift-XRT refined Analysis
  29. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  30. GRB 240912A: Enhanced Swift-XRT position
  31. GRB 240912A: Redshift from OSIRIS+/GTC
  32. Fast X-ray Transient EP240801a: GMRT radio observations
  33. GRB 240912A: Swift detection of a burst with an optical counterpart
  34. GRB 240910A: Fermi GBM Observation
  35. GRB 240910A: JinShan optical observations
  36. GRB 240825A: 7DT Optical Upper Limit
  37. GRB 240905E: SVOM/VT optical observations
  38. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  39. LIGO/Virgo/KAGRA S240910ci: Identification of a GW compact binary merger candidate
  40. GRB 240910A: SVOM/GRM observation
  41. EP240908a: Mondy and AbAO follow-up observations
  42. EP240908a: Updates on the WXT detection result around the trigger time
  43. EP240908a: TRT optical upper limit
  44. EP240908a: EP detection of a fast X-ray transient
  45. GRB 240905E: GIT optical upper limit
  46. GRB 240905E: Gaoyazi/GOT optical upper limits
  47. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  48. GRB 240905E: J-band observations with WINTER
  49. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  50. GRB 240905E: AKO Optical Upper Limit
  51. GRB 240905E: SVOM/C-GFT optical upper limit
  52. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  53. GRB 240905E: NOT optical upper limits
  54. GRB 240905E: REM optical/NIR upper limits
  55. GRB 240905E: Swift-XRT refined Analysis
  56. GRB 240902A: AstroSat CZTI detection of a long burst
  57. GRB 240905E: LCOGT Optical Upper Limit
  58. GRB 240905E: Swift/UVOT Upper Limits
  59. GRB 240905E: SAO RAS optical upper limit
  60. GRB 240905E: Nanshan/HMT optical upper limit
  61. GRB 240905E: Swift detection of a burst
  62. GRB 240905B: AstroSat CZTI detection and localization
  63. GRB 240825A: MeerLICHT afterglow detection
  64. GRB 240828A: SAO RAS AS-500(2) optical observations
  65. GRB 240825A: TSHAO Optical Upper Limit
  66. GRB240828B: REM optical/NIR upper limits
  67. GRB 240828B: AbAO optical upper limit
  68. GRB 240825A: SOAR observations
  69. GRB 240828B: Mephisto optical upper limit
  70. GRB 240828B: GRANDMA Optical Upper Limit
  71. GRB 240828B: J-band upper limit from WINTER
  72. GRB 240828B: GMG Optical Upper Limit
  73. GRB 240828B: SVOM/C-GFT optical upper limit
  74. GRB 240828B: SAO RAS optical upper limit
  75. GRB 240828A: SAO RAS optical observations
  76. GRB 240828A: KAIT Optical Afterglow Candidate
  77. GRB 240825A: SVOM/VT optical detection
  78. GRB 240825A: further SAO RAS optical observations
  79. GRB 240825A: iTelescope optical observations
  80. GRB 240828B: Swift-XRT afterglow detection
  81. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  82. GRB 240821A: PRIME near-infrared observations
  83. GRB 240828B : Detection of a possible very soft X-ray transient by SVOM/ECLAIRs
  84. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  85. GRB 240825A: SAO RAS optical observations
  86. GRB 240824A: GIT optical upper limit
  87. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  88. GRB 240825A: GMG Continued Optical Observation on the Second Night
  89. GRB 240825A: PRIME near-infrared detection
  90. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  91. GRB 240825A: AstroSat CZTI detection of the long bright burst
  92. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  93. GRB 240825A: Swift/UVOT Detection
  94. GRB 240825A: REM detection of the optical/NIR afterglow
  95. GRB 240825A: Montarrenti Observatory optical observations
  96. GRB 240825A: Enhanced Swift-XRT position
  97. GRB 240825A: LCO optical observations
  98. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  99. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  100. GRB 240824B: NOT optical upper limit

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