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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"

16145 results found.

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

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