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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

16141 results found.

  1. EP240804a: NOT optical counterpart detection
  2. GRB 240805A: Swift detection of a burst
  3. EP240802a: Montarrenti Observatory optical upper limit
  4. EP240801a: Osservatorio Astronomico Nastro Verde upper limit
  5. EP240802A: Bassano Bresciano Observatory upper limit
  6. EP240802a: Time coincidence with GRB 240802A and optical upper limits with Kinder observations
  7. EP240801a: further SAO RAS optical observations
  8. EP240801a: optical observations at CrAO and AbAO
  9. EP240801a: GRANDMA and Kilonova-Catcher optical observations
  10. EP240801a: Leavitt Observatory optical observations
  11. EP240801a: GTC spectroscopy and absorption redshift
  12. EP240801a: SAO RAS optical observations
  13. EP240801a: JinShan optical observations
  14. EP240801a: NOT optical observations
  15. EP240801a: follow-up observation with LCOGT
  16. EP240801a: GSP follow-up observations of the candidate counterpart
  17. EP240801a: Kinder follow-up observations of the candidate counterpart
  18. EP240801a: KAIT optical counterpart observations
  19. EP240801a: GMG observation
  20. EP240801a: TRT optical counterpart detection
  21. GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
  22. GRB240730A: BOOTES-5/JGT early optical upper limit
  23. GRB 240730A: KAIT Optical Upper Limit
  24. GRB 240730A: Swift/UVOT Upper Limits
  25. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  26. GRB 240727A: observations of optical counterpart.
  27. GRB 240727A: Swift/UVOT detection
  28. GRB 240727A: Osservatorio Astronomico Nastro Verde upper limit
  29. GRB 240727A: NOT optical observation
  30. GRB 240727A: JinShan optical upper limits
  31. GRB 240727A Bassano Bresciano Observatory upper limit
  32. GRB240529A: VIRT optical transient detection
  33. GRB240727A: Skynet Optical Afterglow Observations
  34. GRB 240727A: TRT optical afterglow detection
  35. GRB 240727A: KAIT Optical Afterglow Candidate
  36. IceCube-Cascade 240714A: TRT optical observations on the EP/FXT positions
  37. GRB 240713A: 2.2m CAHA optical limit
  38. GRB 240715A: Swift/UVOT observations of the XRT sources.
  39. GRB240713A: Swift/UVOT Upper LImits
  40. GRB 240715A: TRT optical upper limit on one Swift/XRT candidate
  41. GRB 240713A: LAST optical upper limit
  42. GRB 240713A: optical upper limits from the INAF Asiago Observatory
  43. GRB240715A: GRANDMA Optical Upper Limits
  44. GRB 240712A: Swift/UVOT Upper Limits
  45. EP-WXT flaring star and the optical flaring activity during its decay phase
  46. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  47. The EP-WXT source triggered on July 14th is likely a flaring star
  48. GRB 240713A: NOT optical upper limits on three EP/FXT candidates
  49. GRB 240713A: JinShan optical upper limits
  50. GRB 240713A: OHP/T120 optical upper limit
  51. GRB240713A: Optical upper limit with Kinder observations
  52. GRB240713A: TAROT and GRANDMA Observations of SVOM/ECLAIRs GRB240713A
  53. GRB240713A : The first probable GRB Located on-Board SVOM by ECLAIRs
  54. EP240708a: GSP optical upper limit
  55. EP240708a: KAIT optical upper limit
  56. EP240708a: NOT optical observations
  57. EP240708a: SVOM/C-GFT optical upper limit
  58. EP240708a: Optical upper limits with Kinder observations
  59. EP240703b: GSP optical upper limit
  60. EP240703b: TRT optical upper limits
  61. EP240703a: TRT further optical observation
  62. EP240702a: TRT optical upper limits
  63. EP240703a: KAIT optical upper limit
  64. EP240703a: BTA observations
  65. EP240703c: Kinder optical follow-up and Swift XRT observations
  66. EP240703a: BOOTES-3 optical upper limit
  67. EP240703a: Liverpool Telescope optical follow-up observations
  68. EP240703a/GRB 240703A: TRT optical candidate likely not real
  69. EP240703a: Kinder optical follow-up observations
  70. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  71. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  72. EP240702a: GSP optical upper limit
  73. EP240626a: Montarrenti Observatory optical upper limit
  74. EP240626a: KAIT optical upper limit
  75. EP240625a: GRANDMA Optical Upper Limits
  76. EP240626a: BOOTES-7 optical upper limit
  77. EP240625a: NOT optical counterpart candidate
  78. GRB240615A: Gemini-North observations of the BAT and XRT positions
  79. GRB240615A: Gemini-North observations of the BAT and XRT positions
  80. EP240618a: NOT further optical observations
  81. EP240618a: NOT optical counterpart candidate
  82. GRB 240529A: JinShan optical observations
  83. EP240618a: GSP optical upper limit
  84. GRB 240619A: Fermi GBM Observation
  85. GRB 240619A: GOTO candidate optical afterglow
  86. EP240618a: Abastumani optical observationsEP240618a
  87. GRB 240615A: NOT optical observations
  88. EP240618a: GRANDMA Optical Upper Limits
  89. EP240618a: TRT optical upper limit
  90. EP240617a: STEP/T80S optical limits
  91. GRB 240615A: possible transient detection from Wendelstein observations
  92. EP240618a: BOOTES-6/DPRT optical upper limit
  93. GRB240615A: 1.3m DFOT optical upper limit
  94. EP240617a: BOOTES-6/DPRT optical upper limit
  95. X-ray transient EP240414a: Chandra late time observation
  96. GRB 240615A: FLWO-1.2m optical upper limits
  97. GRB 240615A: GOTO optical upper limits
  98. GRB 240529A: LBT optical detection and late temporal decay
  99. GRB 240529A : MITSuME Akeno optical afterglow detection
  100. GRB 240529A: SAO RAS optical observations

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