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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"

32739 results found.

  1. GRB 241002C : MITSuME Akeno optical upper limits
  2. LIGO/Virgo/KAGRA S240925n: Updated Sky localization
  3. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  4. GRB241001A: REM optical/NIR upper limits
  5. LIGO/Virgo/KAGRA S241002e: Updated Sky localization
  6. GRB 241002A: Swift/UVOT Upper Limits
  7. EP240930a: Liverpool Telescope observations
  8. GRB 241002A: LCOGT Optical Upper Limits
  9. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  10. GRB 241001A: Swift/UVOT Detection
  11. GRB 241001A: VLT/X-shooter redshift
  12. GRB 241002B: GOTO optical counterpart candidate
  13. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  14. GRB 241001A: correction to GCN 37667
  15. GRB 240929A: Liverpool Telescope prompt followup observations
  16. Fermi GRB 241002B: Global MASTER-Net observations report
  17. GRB 241001A: Swift-XRT observations
  18. GRB241001A: optical afterglow candidate
  19. LIGO/Virgo/KAGRA S241002e: Identification of a GW compact binary merger candidate
  20. LIGO/Virgo/KAGRA S240930du: Updated Sky localization
  21. GRB 240930B: Fermi GBM Observation
  22. GRB 241001A: Swift ToO observations
  23. GRB 240930B: GRBAlpha detection
  24. GRB 240929A: GRBAlpha detection
  25. EP240930a : KAIT optical upper limit
  26. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  27. EP240930a: EP-FXT follow-up observation update
  28. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  29. EP240930a: GOTO optical upper limits
  30. GRB 240929A: SVOM/GRM observation
  31. EP EP240930a: Global MASTER-Net observations report
  32. EP240930a: EP-WXT detection of a fast X-ray transient
  33. LIGO/Virgo/KAGRA S240930du: Identification of a GW compact binary merger candidate
  34. IceCube-240929A: Upper limits from a search for additional neutrino events in IceCube
  35. AMON NuEM 240926A: Swift XRT Follow-up
  36. GRB 240929A : Leavitt Observatory optical upper limit
  37. Fermi GRB 240930B: Global MASTER-Net observations report
  38. IPN triangulation of GRB 240926A
  39. GRB 240825A: LBT optical observations
  40. Fermi GRB 240930A: Global MASTER-Net observations report
  41. Fermi Gamma-ray Burst Monitor trigger 749362078/240930172 (GRB 240930A) is not a GRB
  42. LIGO/Virgo/KAGRA S240930aa: Identification of a GW compact binary merger candidate
  43. GRB 240929A long GRB detected by INTEGRAL
  44. Fermi GRB 240929A: Global MASTER-Net observations report
  45. Konus-Wind detection of GRB 240912A
  46. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  47. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  48. Konus-Wind detection of GRB 240905B
  49. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  50. EP240919a / GRB 240919A: SVOM/VT upper limit
  51. EP240918b and EP240918c: EP-FXT follow-up observations
  52. LIGO/Virgo/KAGRA S240925n: Updated Sky localization and Source Classification
  53. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  54. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  55. LIGO/Virgo/KAGRA S240925n: Identification of a GW compact binary merger candidate
  56. Konus-Wind detection of GRB 240918B
  57. IPN triangulation of GRB 240918B
  58. GRB 240905B: VZLUSAT-2 detection
  59. LIGO/Virgo/KAGRA S240922df: Updated Sky localization
  60. LIGO/Virgo/KAGRA S240920dw: Updated Sky localization
  61. LIGO/Virgo/KAGRA S240921cw: Updated Sky localization
  62. LIGO/Virgo/KAGRA S240924a: Updated Sky localization
  63. LIGO/Virgo/KAGRA S240920bz: Updated Sky localization and Source Classification
  64. LIGO/Virgo/KAGRA S240923ct: Updated Sky localization and Source Classification
  65. EP trigger ID 01709059262: correction to the observation start time and source localization
  66. LIGO/Virgo/KAGRA S240924a: Identification of a GW compact binary merger candidate
  67. LIGO/Virgo/KAGRA S240923ct: Identification of a GW compact binary merger candidate
  68. LIGO/Virgo S240919bn: GOTO optical upper limits
  69. GRB 240918B: AstroSat CZTI detection
  70. LIGO/Virgo/KAGRA S240922df: Identification of a GW compact binary merger candidate
  71. LIGO/Virgo/KAGRA S240921cw: Identification of a GW compact binary merger candidate
  72. EP240919a: EP-FXT follow-up observation update
  73. EP240913A/GRB 240913C: AbAO optical upper limit
  74. EP240919a / GRB 240919A: Mondy optical upper limit
  75. EP240913a/GRB 240913C: 1.6m Mephisto observations
  76. EP240918a: SVOM/VT upper limit
  77. Fermi GBM Sub-Threshold Detection of GRB240919A / EP240919a
  78. EP240919a / GRB 240919A: REM optical and NIR upper limits
  79. EP240919a / GRB 240919A: KAIT optical upper limit
  80. EP240918b and EP240918c: Optical upper limits with Kinder observations
  81. GRB 240414A: further radio observations with the VLA
  82. EP240919a: Optical upper limit with Kinder observations
  83. GRB 240919A / EP240919a: SVOM/GRM observation
  84. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  85. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  86. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  87. EP EP240919a: Global MASTER-Net observations report
  88. GRB 240910A: radio detection with the VLA
  89. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  90. EP240919a: NOT and Gemini optical observations
  91. EP240919a: GOTO optical upper limits
  92. EP240919a: JinShan optical upper limits
  93. EP240919a is likely a GRB event (duplicate submission of 37563)
  94. EP240919a is likely a GRB event
  95. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  96. GRB 240918A and GRB 240918B : INTEGRAL SPI ACS LIGHT CURVE
  97. LIGO/Virgo/KAGRA S240919bn: Updated Sky localization
  98. GRB 240918B: Fermi GBM Detection
  99. LIGO/Virgo/KAGRA S240917cb: Updated Sky localization and EM Bright Classification
  100. LIGO/Virgo/KAGRA S240916ar: Updated Sky localization and EM Bright Classification

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