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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"
  1. GRB 170826B: Fermi GBM detection
  2. LIGO/Virgo G299232: CALET Observations
  3. GRB 170826A: Fermi GBM detection
  4. LIGO/Virgo G298936: Astrosat CZTI upper limits
  5. LIGO/Virgo G299232: XRT Rank 2 source is not real
  6. LIGO/Virgo G299232: Astrosat CZTI upper limits
  7. LIGO/VIRGO G299232: Fermi GBM Observations
  8. LIGO/Virgo G299232 : Fermi-LAT search for high-energy gamma-ray counterpart
  9. LIGO/Virgo G298389: HAWC follow-up
  10. LIGO/Virgo G298048: uGMRT Follow-up of SSS17a at 400 MHz and 1.4 GHz
  11. LIGO/Virgo G299232: Nearby Galaxies in the Localization Volume
  12. LIGO/Virgo G298936: CALET Observations
  13. GRB 170820A CALET Gamma-Ray Burst Monitor detection
  14. LIGO/Virgo G299232: Swift/BAT data search
  15. LIGO/VIRGO G298048: INAF VST-ESO PARANAL observations of NGC4993
  16. GRB 170822A: AstroSat CZTI detection
  17. LIGO/Virgo G299232: AGILE GRID observations
  18. LIGO/Virgo G299232: AGILE MCAL detection of a short gamma-ray candidate
  19. LIGO/Virgo G299232: INTEGRAL search for a prompt gamma-ray counterpart
  20. LIGO/Virgo G299232: COINCIDENT IceCube neutrino observation UPDATE
  21. LIGO/Virgo G296853: VLT observations by GLGW Hunters
  22. LIGO/Virgo G299232 ANTARES search
  23. LIGO/Virgo G297595: INTEGRAL pointed follow-up observations
  24. LIGO/Virgo G299232: FOUND COINCIDENT IceCube neutrino observation
  25. LIGO/Virgo G299232: Identification of a GW Compact Binary Coalescence Candidate
  26. LIGO/Virgo G297595: Gemini and VLT observations by GLGW Hunters
  27. LIGO/Virgo G298936: Liverpool Telescope Spectoscopy of GWFUNC-17ure
  28. LIGO/Virgo G298936 TAROT/TZAC observations
  29. GRB 170825A: AGILE/MCAL Detection
  30. LIGO/Virgo G298936 : MAXI/GSC observations
  31. LIGO/Virgo G298048: MASTER Global-Net early optical observations and the Possible KiloNova SSS17a in NGC 4993 photometry and merging rate
  32. LIGO/Virgo G298048: Pierre Auger Observatory neutrino follow-up
  33. LIGO/Virgo G298048: Subaru HSC z-band imaging of the OT candidate SSS17a
  34. LIGO/Virgo G298048: Near-infrared fading from Gemini-South
  35. LIGO/Virgo G298048: HAWC follow-up
  36. LIGO/Virgo G298048: Gemini-South Imaging and Spectroscopy
  37. LIGO/Virgo G298048: MUSE Integral Field Observations
  38. LIGO/Virgo G298048: LWA radio observations
  39. Konus-Wind observation of GRB 170822A
  40. GRB 170823A: Swift-BAT refined analysis
  41. LIGO/VIRGO G298048: AAT/AAO spectroscopic observations of the GW counterpart candidate SSS17a/DLT17ck
  42. LIGO/Virgo G298048: LOFAR follow-up
  43. LIGO/Virgo G298936: GWFUNC/CNEOST optical observations and an optical transient
  44. LIGO/Virgo G298048: H.E.S.S. very-high energy gamma-ray follow-up
  45. LIGO/Virgo G297595: H.E.S.S. very-high energy gamma-ray follow-up
  46. LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
  47. LIGO/Virgo G298048: Results of the ASKAP search for fast radio bursts
  48. LIGO/Virgo G298048: ATCA follow-up of SSS17a in NGC 4993
  49. LIGO/Virgo G298048: Properties of NGC 4993
  50. LIGO/Virgo G298389: CALET Observations
  51. LIGO/Virgo G298936 : Fermi-LAT search for a high-energy gamma-ray counterpart
  52. GRB 170823A: Swift detection of a burst
  53. LIGO/Virgo G298936: Swift/BAT data search
  54. LIGO/Virgo G298048: Continued VLA monitoring at 6 GHz
  55. LIGO/VIRGO G298936: Fermi GBM Observations
  56. LIGO/Virgo G298936: AGILE GRID observations
  57. LIGO/Virgo G298936: Updated localization from gravitational-wave data
  58. LIGO/Virgo G298936: AGILE MCAL observations
  59. LIGO/Virgo G298936 ANTARES search
  60. LIGO/Virgo G298936: INTEGRAL was inactive at the time of the event
  61. LIGO/Virgo G298936: IceCube neutrino observations
  62. LIGO/Virgo G298936: Identification of a GW Binary Black Hole Candidate
  63. GRB 170822A: RATIR Optical and NIR Observations
  64. GRB 170822A: AbAO optical upper limit
  65. LIGO/Virgo G298048: ESO/VLT optical observations
  66. GRB 170822A: MITSuME Akeno Optical Observation
  67. GRB 170822A: Swift-BAT refined analysis
  68. LIGO/VIRGO G298048: VLA/JAGWAR observations of the CLU galaxies
  69. GRB 170822A: Swift/UVOT Upper Limits
  70. LIGO/Virgo G298048: Chandra X-ray observations
  71. GRB 170822A: Swift-XRT refined Analysis
  72. LIGO/Virgo G298389 : MAXI/GSC observations
  73. LIGO/Virgo G298048: Global properties and star-formation rate of NGC 4993
  74. LIGO/Virgo G298048: observations of optical counterpart candidate with CHILESCOPE observatory
  75. GRB 170822A: Enhanced Swift-XRT position
  76. GRB 170822A:BOOTES-5/JGT optical afterglow candidate
  77. LIGO/Virgo G298048: CALET Observations
  78. GRB 170822A: Swift detection of a burst
  79. LIGO/Virgo G298048: ASKAP observations of SSS17a and NGC 4993 at 1.345 GHz
  80. LIGO/Virgo G298048: Gemini-South Near-Infrared Spectroscopy
  81. LIGO/Virgo G298048: MWA Observations of Error Region
  82. LIGO/Virgo G298048: VLA observation at 15 GHz
  83. LIGO/Virgo G298048: observations of optical counterpart candidate with CHILESCOPE observatory
  84. LIGO/Virgo G298048: TOROS Spectra observation with CASLEO
  85. LIGO/Virgo G298048: Pan-STARRS izy photometry of SSS17a/DLT17ck
  86. LIGO/Virgo G298048: Continued monitoring of the optical counterpart candidate
  87. LIGO/Virgo G298048 ANTARES search (2)
  88. Konus-Wind observation of GRB 170816A
  89. LIGO/Virgo G298048: Correction to ATCA 8.5 GHz observations
  90. LIGO/Virgo G298048: ATCA 8.5 GHz observations of galaxies in the localisation volume
  91. LIGO/Virgo G298048: Zadko observations of the OT candidate SSS17a/DLT17ck
  92. LIGO/Virgo G298048: NuSTAR limits on X-ray emission
  93. LIGO/Virgo G298048: ASKAP follow up
  94. LIGO/Virgo G298048: optical observations with BOOTES-5 at San Pedro Mártir
  95. LIGO/Virgo G298048: Kanata/HONIR NIR photometry of the possible counterpart of G298048
  96. LIGO/Virgo G298389: Swift/BAT data search
  97. LIGO/Virgo G298048: On the kick velocity and age of the binary Neutron Stars Progenitor
  98. LIGO/Virgo G298048: TOROS optical counterpart search (continuation)
  99. LIGO/Virgo G298048: TOROS optical counterpart search
  100. LIGO/Virgo G298048: optical observations of CHILESCOPE observatory

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