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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.

Advanced Search Examples (click to copy):

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

32503 results found.

  1. EP240806a: KAIT optical observations
  2. GRB 240805B: Swift-BAT refined analysis
  3. GRB 240805A: Swift-BAT refined analysis
  4. EP240804a (GRB 240804B): NOT optical observations
  5. EP240806a: LCOGT optical counterpart detection
  6. Konus-Wind detection of GRB 240802A (EP240802a)
  7. Improved IPN triangulation of GRB 240802A / EP 240802a
  8. Konus-Wind detection of GRB 240805A
  9. GRB 240805B Bassano Bresciano Observatory upper limit
  10. GRB240805A: Fermi GBM Observation
  11. GRB 240805B: JinShan optical afterglow detection
  12. GRB 240804B/EP240804a: Correction to the GRB name in GCN 37071
  13. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  14. Konus-Wind detection of GRB 240804B (a counterpart of EP240804a)
  15. EP240806a: EP-FXT detection of the X-ray emission
  16. GRB 240624B: VZLUSAT-2 detection
  17. GRB 240619C: VZLUSAT-2 detection
  18. EP 240806A: LCO optical observations
  19. GRB 240805B: Optical detection with 1.6m Mephisto
  20. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
  21. GRB 240805B: Swift/UVOT Upper Limits
  22. GRB 240805A: Swift/UVOT Upper Limits
  23. GRB 240805B: BTA optical afterglow candidate
  24. GRB 240805A: SVOM/GRM observation
  25. GRB 240805B: LCOGT Optical Upper Limits
  26. Swift GRB 240805B: Global MASTER-Net observations report
  27. GRB 240805B: JinShan optical upper limits
  28. EP240801a: BTA BVRI photometry
  29. Fermi GRB 240805A: Global MASTER-Net observations report
  30. Swift GRB 240805A: Global MASTER-Net observations report
  31. GRB 240805A: Fermi-LAT detection
  32. GRB 240805A: INTEGRAL spectral analysis
  33. EP240801a: Continued optical observations at ZTSh (CraO)
  34. EP240804a: VLT/X-shooter spectroscopic redshift
  35. EP240804a: LCOGT optical counterpart detection
  36. GRB 240805A: A long GRB detected by INTEGRAL
  37. EP240804a: NOT optical counterpart detection
  38. EP240802a: correction of EP-WXT trigger time in GCN 37019
  39. Fermi GRB 240804A: Global MASTER-Net observations report
  40. EP240802a: Montarrenti Observatory optical upper limit
  41. IPN triangulation of GRB 240802A / EP 240802a
  42. EP240801a: Osservatorio Astronomico Nastro Verde upper limit
  43. EP240802A: Bassano Bresciano Observatory upper limit
  44. GRB 240802A: SVOM/GRM observation
  45. EP240802a: Time coincidence with GRB 240802A and optical upper limits with Kinder observations
  46. EP240801a: further SAO RAS optical observations
  47. EP240801a: optical observations at CrAO and AbAO
  48. EP240801a: GRANDMA and Kilonova-Catcher optical observations
  49. EP240801a: Leavitt Observatory optical observations
  50. EP240801a: GTC spectroscopy and absorption redshift
  51. EP240801a: SAO RAS optical observations
  52. GRB 240801B: AstroSat CZTI Updated classification - likely a solar flare
  53. EP240801a: JinShan optical observations
  54. GRB 240727C: SVOM/GRM observation
  55. EP240801a: NOT optical observations
  56. EP240801a: follow-up observation with LCOGT
  57. Fermi GBM trigger 744179961 / 240801194 can not be confirmed as a GRB
  58. GRB 240730A: Swift-BAT refined analysis
  59. EP240801a: GSP follow-up observations of the candidate counterpart
  60. EP240801a: Kinder follow-up observations of the candidate counterpart
  61. EP240708a: Kinder follow-up observations of the candidate counterpart (duplicate submission of GCN 37002)
  62. EP240801a: KAIT optical counterpart observations
  63. EP240801a: GMG observation
  64. EP240801a: TRT optical counterpart detection
  65. Fermi GRB 240801A: Global MASTER-Net observations report
  66. GRB 240731A: Fermi GBM Final Localization
  67. GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
  68. Fermi GRB 240730B: Global MASTER-Net observations report
  69. Swift GRB 240730A: Global MASTER-Net observations report
  70. GRB 240715A: Swift-XRT afterglow detection
  71. GRB 240730A: KAIT Optical Upper Limit
  72. GRB 240727C: GRBAlpha detection
  73. GRB 240730A: Swift/UVOT Upper Limits
  74. GRB 240727A: Swift-BAT refined analysis
  75. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  76. GRB 240727A: observations of optical counterpart.
  77. GRB 240727B: Swift-XRT observations
  78. Fermi GRB 240727A: Global MASTER-Net observations report
  79. GRB 240727A: Swift/UVOT detection
  80. GRB 240727A: Osservatorio Astronomico Nastro Verde upper limit
  81. GRB 240727A: NOT optical observation
  82. GRB 240727A: JinShan optical upper limits
  83. GRB 240727A Bassano Bresciano Observatory upper limit
  84. GRB 240727D: Correction to the GRB name in GCN 36958
  85. GRB 240720B: GRBAlpha detection
  86. GRB 240718A: GRBAlpha detection
  87. GRB 240627A: GRBAlpha detection
  88. Fermi GRB 240726A: Global MASTER-Net observations report
  89. GRB 240727B: Fermi GBM Observation
  90. GRB240529A: VIRT optical transient detection
  91. GRB 240727B: Swift ToO observations
  92. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  93. GRB 240726A: SVOM/GRM observation
  94. GRB240727A: Skynet Optical Afterglow Observations
  95. GRB 240727A: TRT optical afterglow detection
  96. GRB 240727A: KAIT Optical Afterglow Candidate
  97. GRB 240726A: AstroSat CZTI detection of a short burst
  98. IceCube-240725A: Upper limits from a search for additional neutrino events in IceCube
  99. Fermi-LAT gamma-ray observations of IceCube-240725A
  100. IceCube-240721A: Two candidates from the Zwicky Transient Facility

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