Skip to main content
Circulars over Kafka event name backfill. 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"

4714 results found.

  1. GRB 230728A: Swift detection of a burst
  2. GRB 230727A: Swift/BAT-GUANO detection of a burst
  3. GRB 230727A: Fermi GBM Final Real-time Localization
  4. IBAS trigger number 10337: not a real GRB
  5. IPN triangulation of GRB 230723A (short)
  6. IceCube Alert 230724.08: Global MASTER-Net observations report
  7. Fermi trigger No 711805358: Global MASTER-Net observations report
  8. GRB 230703A detected with multiple GRID detectors
  9. GRB 230707A: Fermi GBM Detection
  10. Fermi GRB 230707A: Global MASTER-Net observations report
  11. GRB 230707A: Fermi GBM Final Real-time Localization
  12. LVK S230619bd/GBM-230619: Upper limits from a two-week IceCube neutrino search
  13. LIGO/Virgo/KAGRA S230627c: GRANDMA observations of galaxies and ZTF counterpart candidates
  14. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  15. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  16. LIGO/Virgo/Kagra S230627c: NED Galaxies in the Localization Volume
  17. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  18. LIGO/Virgo S230622e: Global MASTER-Net observations report
  19. LIGO/Virgo S230621bq: Global MASTER-Net observations report
  20. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  21. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  22. LIGO/Virgo S230620au: Global MASTER-Net observations report
  23. LIGO/Virgo S230620z: Global MASTER-Net observations report
  24. LIGO/Virgo S230620w: Global MASTER-Net observations report
  25. LIGO/Virgo S230619bg: Global MASTER-Net observations report
  26. LIGO/Virgo S230618s: Global MASTER-Net observations report
  27. GRB 230618A: Swift-XRT refined Analysis
  28. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  29. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  30. LIGO/Virgo S230618k: Global MASTER-Net observations report
  31. LIGO/Virgo S230618d: Global MASTER-Net observations report
  32. LIGO/Virgo S230617bc: Global MASTER-Net observations report
  33. LIGO/Virgo S230617aq: Global MASTER-Net observations report
  34. LIGO/Virgo S230617ab: Global MASTER-Net observations report
  35. Swift GRB 230618A: Global MASTER-Net observations report
  36. LIGO/Virgo S230617aj: Global MASTER-Net observations report
  37. GRB230618A: LCOGT Optical Observations
  38. GRB 230618A: Prompt enhanced Swift-XRT position
  39. GRB 230618A: Swift detection of a burst
  40. LIGO/Virgo/KAGRA S230615az: Non-Detections of GROWTH-India Candidates from GECKO Optical Observations
  41. LIGO/Virgo S230615be: Global MASTER-Net observations report
  42. LIGO/Virgo/KAGRA S230615az: GROWTH-India candidates
  43. GRB 230606A: LCOGT Optical Observations
  44. LIGO/Virgo S230608aw: Global MASTER-Net observations report
  45. LIGO/Virgo S230609a: Global MASTER-Net observations report
  46. LIGO/Virgo S230608ah: Global MASTER-Net observations report
  47. LIGO/Virgo S230608q: Global MASTER-Net observations report
  48. ZTF23aamxeqf/AT2023jxk: 1.3m DFOT Optical upper limit
  49. Fermi trigger No 707039690: Global MASTER-Net observations report
  50. ZTF and GIT Observations of the Candidate Optical Afterglow AT2023jxk
  51. LIGO/Virgo S230606d: Global MASTER-Net observations report
  52. Fermi-LAT gamma-ray observations of IceCube-230603A
  53. IceCube-230603A: Upper limits from a search for additional neutrino events in IceCube
  54. IceCube-230603A - IceCube observation of a high-energy neutrino candidate track-like event
  55. LIGO/Virgo S230603aa: Global MASTER-Net observations report
  56. LIGO/Virgo S230602ap: Global MASTER-Net observations report
  57. GRB 230522A: GRBAlpha and VZLUSAT-2 joint detection
  58. LIGO/Virgo S230529ay: Global MASTER-Net observations report
  59. LIGO/Virgo S230525a: Global MASTER-Net observations report
  60. Fermi trigger No 706610076: Global MASTER-Net observations report
  61. Fermi Gamma-ray Burst Monitor trigger 706536788/230523509 is not a GRB
  62. LIGO/Virgo S230522a: Global MASTER-Net observations report
  63. LIGO/Virgo S230521k: Global MASTER-Net observations report
  64. Fermi Gamma-ray Burst Monitor trigger 706338208/230521211 is not a GRB
  65. LIGO/Virgo S230520ae: Global MASTER-Net observations report
  66. Fermi trigger No 706331483: Global MASTER-Net observations report
  67. Fermi trigger No 706317104: Global MASTER-Net observations report
  68. GRB 230520A: CALET Gamma-Ray Burst Monitor detection
  69. GRB 230521A: Fermi GBM Final Real-time Localization
  70. LIGO/Virgo/KAGRA S230518h: ATCA follow-up of candidate counterparts
  71. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  72. GRB 230520A: MAXI/GSC detection
  73. LIGO/Virgo/Kagra S230518h: NED Galaxies in the Localization Volume
  74. LIGO/Virgo S230518h: Global MASTER-Net observations report
  75. GRB 230513A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  76. GRB 230512A: Liverpool Telescope observations
  77. Fermi-LAT gamma-ray observations of IceCube-230511A
  78. GRB 230510A: OHP/T193 and OHP/T120 optical observations
  79. IceCube-230511A: Upper limits from a search for additional neutrino events in IceCube
  80. GRB 230510A: LCOGT Optical Upper Limit
  81. IceCube-230511A: IceCube observation of a high-energy neutrino candidate
  82. GRB 230511C: Fermi GBM Final Localization
  83. GRB 230510B: MAXI/GSC detection
  84. Fermi trigger No 705413051: Global MASTER-Net observations report
  85. Fermi Gamma-ray Burst Monitor trigger 230510133/705381054 is not a GRB
  86. GRB 230506C: NUTTelA-TAO / BSTI Early Optical Limits
  87. Fermi trigger No 704365743: Global MASTER-Net observations report
  88. GRB 230420A: BOOTES-5/JGT optical afterglow detection
  89. GRB 230307A: iTelescope optical upper limit (likely)
  90. GRB 230409B: OHP/T193 optical upper limit
  91. Fermi GRB 230409C: Global MASTER-Net observations report
  92. GRB 230405B: AGILE detection
  93. GRB 230405B: Fermi GBM Observation
  94. IceCube Alert 230405.56: Global MASTER-Net observations report
  95. GRB 230405B: Swift detection of a burst
  96. GRB 230405B: Fermi GBM Final Real-time Localization
  97. GRB 230405A: Fermi GBM Final Real-time Localization
  98. IceCube-230401A: Upper limits from a search for additional neutrino events in IceCube
  99. GRB 230328B: Multa observatory optical afterglow observation
  100. IceCube-Cascade 230329A: Upper limits from a search for additional neutrino events in IceCube

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov