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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"

45783 results found.

  1. EP240913a/GRB 240913C: KAIT optical upper limit
  2. EP240913a / GRB 240913C INTEGRAL SPI ACS LIGHT CURVE
  3. GRB 240913C: Fermi GBM detection
  4. GRB 240914A: Swift-XRT observations
  5. GRB 240913C: Joint location by ETJASMIN
  6. GRB 240914B: AstroSat CZTI detection
  7. EP240913A / GRB 240913C: AstroSat CZTI detection
  8. GRB 240914A: SVOM/GRM observation
  9. GRB 240910A: SVOM/VT optical observations
  10. GRB 240914A: Swift ToO observations
  11. EP240913a: NOT optical upper limits
  12. EP240913a: JinShan optical upper limits
  13. EP240913a: ESO-NTT optical observations
  14. GRB 240914A: ESO-NTT optical observations
  15. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  16. GRB 240914B: BALROG localization (Fermi Trigger 747990592 / GRB 240914298)
  17. GRB 240914A : An intermediate duration GRB located on-board by SVOM/ECLAIRs.
  18. GRB 240905E: further NOT optical observations
  19. EP240913a: A GRB Event
  20. EP240913a: EP-WXT detection of a fast X-ray transient
  21. GRB 240913B: Fermi GBM Final Real-time Localization
  22. GRB 240911A: LCO optical observations
  23. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  24. Fermi Gamma-ray Burst Monitor trigger 747837485/240912526 is not a GRB
  25. GRB 240912A: Swift/UVOT Detection
  26. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  27. Fermi trigger No 747920561: Global MASTER-Net observations report
  28. GRB 240912A: SVOM/GRM observation
  29. GRB 240911A: Swift-XRT observations
  30. Fermi GRB 240913A: Global MASTER-Net observations report
  31. GRB 240913A: Fermi GBM Final Real-time Localization
  32. GRB 240912A: J-band observations with WINTER
  33. GRB 240912A: Swift-XRT refined Analysis
  34. GRB 240912A: Fermi GBM Observation
  35. Swift GRB 240912A: Global MASTER-Net observations report
  36. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  37. GRB 240911A: Tiled Swift observations
  38. Fermi Gamma-ray Burst Monitor trigger 747839931/240912555 is not a GRB
  39. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  40. GRB 240912B: Fermi GBM Final Real-time Localization
  41. GRB 240912A: NOT optical spectroscopy
  42. GRB 240912A: Enhanced Swift-XRT position
  43. GRB 240912A: Redshift from OSIRIS+/GTC
  44. Fast X-ray Transient EP240801a: GMRT radio observations
  45. GRB 240910A: Redshift from OSIRIS+/GTC
  46. GRB 240912A: Swift detection of a burst with an optical counterpart
  47. GRB 240912A: Fermi GBM Final Real-time Localization
  48. GRB 240910A: Fermi GBM Observation
  49. GRB 240910A: NOT optical observations
  50. GRB 240911A : a likely weak GRB detected by SVOM/ECLAIRs
  51. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  52. GRB 240910A: JinShan optical observations
  53. GRB 240910A: GOTO candidate optical counterpart
  54. EP240908a: Optical afterglow confirmation
  55. GRB 240710A: SVOM/GRM observation
  56. GRB 240910A: Swift ToO observations
  57. IPN triangulation of GRB 240905B (short)
  58. GRB 240825A: 7DT Optical Upper Limit
  59. GRB 240905E: SVOM/VT optical observations
  60. GRB 240905E: SVOM/VT optical observations (duplicate submission of GCN 37453)
  61. LIGO/Virgo/KAGRA S240910ci: NED Galaxies in the Localization Volume
  62. GRB 240910A: GRBAlpha detection
  63. GRB 240910B: Fermi GBM Final Real-time Localization
  64. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  65. LIGO/Virgo/KAGRA S240910ci: Updated Sky localization and EM Bright Classification
  66. LIGO/Virgo/KAGRA S240910ci: Identification of a GW compact binary merger candidate
  67. GRB 240910A: SVOM/GRM observation
  68. EP240908a: Mondy and AbAO follow-up observations
  69. EP240908a: Updates on the WXT detection result around the trigger time
  70. Fermi GRB 240910A: Global MASTER-Net observations report
  71. GRB 240910A: Fermi GBM Final Real-time Localization
  72. LIGO/Virgo/KAGRA S240908bs: Upper limits from Swift/BAT-GUANO
  73. LIGO/Virgo/KAGRA S240907cg: Upper limits from Swift/BAT-GUANO
  74. EP240908a: optical afterglow candidate
  75. EP EP240908a: Global MASTER-Net observations report
  76. GRB 240905B: Fermi GBM Observation
  77. Fermi trigger No 747553301: Global MASTER-Net observations report
  78. EP240908a: TRT optical upper limit
  79. GRB 240905B: GOTO optical upper limits
  80. EP240908a: EP detection of a fast X-ray transient
  81. Fermi GRB 240908A: Global MASTER-Net observations report
  82. LIGO/Virgo/KAGRA S240908dg: Updated Sky localization
  83. LIGO/Virgo/KAGRA S240908bs: Updated Sky localization
  84. GRB 240908A: Fermi GBM Final Real-time Localization
  85. LIGO/Virgo/KAGRA S240908dg: Identification of a GW compact binary merger candidate
  86. LIGO/Virgo/KAGRA S240908bs: Identification of a GW compact binary merger candidate
  87. LIGO/Virgo/KAGRA S240907cg: Updated Sky localization
  88. GRB 240801A: SVOM/GRM observation
  89. LIGO/Virgo/KAGRA S240907cg: Identification of a GW compact binary merger candidate
  90. GRB 240905E: GIT optical upper limit
  91. GRB 240905B: Swift-XRT observations
  92. GRB 240905E: Gaoyazi/GOT optical upper limits
  93. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  94. GRB 240905B: Fermi-LAT detection
  95. GRB 240905B: Swift ToO observations
  96. GRB 240905E: J-band observations with WINTER
  97. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  98. GRB 240905E: AKO Optical Upper Limit
  99. GRB 240905E: SVOM/C-GFT optical upper limit
  100. GRB 240905E: OHP/MISTRAL T193 optical upper limit

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