Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. See news and announcements

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"
  1. GRB 190630C: Swift-BAT refined analysis
  2. GRB 190701A: Enhanced Swift-XRT position
  3. GRB 190630C: AstroSat CZTI detection
  4. LIGO/Virgo S190630ag: No counterpart candidates in the Swift/BAT Observations
  5. GRB 190701A: MAXI/GSC detection
  6. GRB 190701B: a long GRB detected by IBAS
  7. GRB 190701A: Prompt enhanced Swift-XRT position
  8. GRB 190701A: Swift detection of a burst
  9. LIGO/Virgo S190630ag: No counterpart candidates in AGILE-MCAL observations
  10. LIGO/Virgo S190630ag: No counterpart candidates in Fermi-LAT observations
  11. GRB 190630B: KAIT Optical Afterglow Confirmation
  12. GRB 190630C: Enhanced Swift-XRT position
  13. Swift GRB190631. Global MASTER-Net observations report
  14. LIGO/Virgo S190630ag: Upper limits from Fermi-GBM Observations
  15. GRB 190630C: Swift detection of a burst
  16. LIGO/Virgo S190630ag: Coverage and upper limits from MAXI/GSC observations
  17. LIGO/Virgo S190630ag: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  18. LIGO/Virgo S190630ag: No neutrino counterpart candidates in ANTARES search
  19. LIGO/Virgo S190630ag: No counterpart candidates in HAWC observations
  20. LIGO/Virgo S190630ag: Identification of a GW compact binary merger candidate
  21. LIGO/Virgo S190630ag Global MASTER-Net observations report
  22. LIGO/Virgo S190630ag: Upper limits from IceCube neutrino searches
  23. GRB 190630B: Swift-XRT refined Analysis
  24. GRB 190630B, Swift-BAT refined analysis
  25. IceCube-190629A: Upper limits from Fermi-GBM Observations
  26. GRB 190627A: VLT/FORS2 spectroscopic redshift
  27. Fermi trigger No 583567803 Global MASTER-Net observations report
  28. GRB Swift Trigger 912102: KAIT Optical Afterglow Candidate
  29. Swift Trigger 912102: possible GRB 190630B
  30. GRB 190630A: Fermi GBM Final Real-time Localization
  31. GRB 190627A: Koshka Zeiss-1000 optical counterpart observations
  32. IceCube-190629A - IceCube observation of a high-energy neutrino candidate event
  33. Baksan Neutrino Observatory Alert 190629.56 Global MASTER-Net observations report
  34. IceCube Alert 190629.81 Global MASTER-Net observations report
  35. GRB 190627A : Xinglong 2.16m optical observation
  36. GRB 190627A: Swift-XRT refined Analysis
  37. GRB 190627A: GMG observation at the second epoch
  38. GRB 190627A: NOT optical observations
  39. GRB 190627A: Optical imaging by D50 from Ondrejov
  40. GRB 190627A: NIR imaging from Liverpool Telescope
  41. GRB 190627A: Optical imaging and spectroscopy from Calar Alto
  42. GRB 190627A: NUTTelA-TAO optical counterpart observations
  43. GRB 190627A: Swift-BAT refined analysis (short-soft burst)
  44. GRB 190610A: Further Swift-XRT observations
  45. GRB 190628A: Fermi GBM Final Real-time Localization
  46. GRB 190627A: GMG observation
  47. GRB 190627A: MASTER optical counterpart observation
  48. GRB190627A: VIRT Afterglow observation
  49. GRB 190627A: Montarrenti Observatory optical detection
  50. GRB 190627A: NUTTelA-TAO optical observations
  51. Fermi trigger No 583327924 Global MASTER-Net observations report
  52. GRB 190627A: Enhanced Swift-XRT position
  53. GRB 190627A: Swift/UVOT Detection
  54. GRB 190627A: Swift detection of a burst
  55. Fermi trigger No 583245413 Global MASTER-Net observations report
  56. Fermi trigger No 583245413 Global MASTER-Net observations report
  57. Fermi trigger No 583221986 Global MASTER-Net observations report
  58. GRB 190626B: Fermi GBM Final Real-time Localization
  59. GRB 190619B: AstroSat CZTI detection
  60. GRB 190626A: Fermi GBM Final Real-time Localization
  61. Fermi trigger No 583111521 Global MASTER-Net observations report
  62. Swift Trigger 911102 is likely not an astrophysical event
  63. IceCube-190619A: prompt emission upper limits from AstroSat-CZTI
  64. Swift GRB190624.86 Global MASTER-Net observations report
  65. Swift trigger 911102: D50 optical limit
  66. Swift Trigger 911102: a possible GRB
  67. GRB 190623A: Fermi GBM Final Real-time Localization
  68. Fermi trigger No 582886211 Global MASTER-Net observations report
  69. GRB 190622A: BALROG localization (Fermi Trigger 582886211 / GRB 190622368)
  70. GRB 190622A: Fermi GBM Final Real-time Localization
  71. Fermi trigger No 582856902 Global MASTER-Net observations report
  72. GRB 190615B: AstroSat CZTI detection
  73. Fermi trigger No 582748289 Global MASTER-Net observations report
  74. Fermi trigger No 582759998 Global MASTER-Net observations report
  75. Fermi-LAT Gamma-ray Observations of IceCube-190619A
  76. IceCube-190619A: No counterpart candidates in ANTARES data
  77. IceCube-190619A: IceCube additional correlated neutrino search: upper limits
  78. IceCube-190619A - HAWC follow-up
  79. LIGO/Virgo S190426c: Swift UVOT - no new counterpart candidates identified
  80. LIGO/Virgo S190510g: Swift UVOT - no new counterpart candidates identified
  81. GRB 190620A: BALROG localization (Fermi Trigger 582725415 / GRB 190620507)
  82. GRB 190620A: Fermi GBM Final Real-time Localization
  83. Fermi trigger No 582615488 Global MASTER-Net observations report
  84. IceCube-190619A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  85. Fermi trigger No 582615488 Global MASTER-Net observations report
  86. IceCube-190619A: not observable by Fermi-GBM
  87. Fermi GBM trigger 190619235/582615488 likely not a GRB
  88. IceCube-190619A - IceCube observation of a high-energy neutrino candidate event
  89. Fermi trigger No 582646590 Global MASTER-Net observations report
  90. GRB 190619B: BALROG localization (Fermi Trigger 582646590 / GRB 190619595)
  91. GRB 190619B: Fermi GBM Final Real-time Localization
  92. GRB 190613A: SEDM Observations
  93. Fermi trigger No 582596766 Global MASTER-Net observations report
  94. GRB 190613B: JCMT SCUBA-2 sub-mm observations
  95. GRB 190619A: Fermi GBM Final Real-time Localization
  96. GRB 190613B: AstroSat CZTI detection
  97. GRB 190611B: AstroSat CZTI detection
  98. Konus-Wind observation of GRB 190613B
  99. GRB 190615B: Insight-HXMT/HE detection
  100. GRB 190615A: Insight-HXMT/HE detection

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov