Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

35423 results found.

  1. GRB 240913C: Joint location by ETJASMIN
  2. GRB 240914B: AstroSat CZTI detection
  3. EP240913A / GRB 240913C: AstroSat CZTI detection
  4. GRB 240914A: SVOM/GRM observation
  5. GRB 240910A: SVOM/VT optical observations
  6. GRB 240914A: Swift ToO observations
  7. EP240913a: ESO-NTT optical observations
  8. GRB 240914A: ESO-NTT optical observations
  9. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  10. GRB 240914B: BALROG localization (Fermi Trigger 747990592 / GRB 240914298)
  11. GRB 240914A : An intermediate duration GRB located on-board by SVOM/ECLAIRs.
  12. GRB 240905E: further NOT optical observations
  13. EP240913a: A GRB Event
  14. GRB 240913B: Fermi GBM Final Real-time Localization
  15. GRB 240911A: LCO optical observations
  16. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  17. Fermi Gamma-ray Burst Monitor trigger 747837485/240912526 is not a GRB
  18. GRB 240912A: Swift/UVOT Detection
  19. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  20. GRB 240912A: SVOM/GRM observation
  21. GRB 240911A: Swift-XRT observations
  22. Fermi GRB 240913A: Global MASTER-Net observations report
  23. GRB 240913A: Fermi GBM Final Real-time Localization
  24. GRB 240912A: J-band observations with WINTER
  25. GRB 240912A: Swift-XRT refined Analysis
  26. GRB 240912A: Fermi GBM Observation
  27. Swift GRB 240912A: Global MASTER-Net observations report
  28. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  29. GRB 240911A: Tiled Swift observations
  30. Fermi Gamma-ray Burst Monitor trigger 747839931/240912555 is not a GRB
  31. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  32. GRB 240912B: Fermi GBM Final Real-time Localization
  33. GRB 240912A: NOT optical spectroscopy
  34. GRB 240912A: Enhanced Swift-XRT position
  35. GRB 240912A: Redshift from OSIRIS+/GTC
  36. GRB 240910A: Redshift from OSIRIS+/GTC
  37. GRB 240912A: Swift detection of a burst with an optical counterpart
  38. GRB 240912A: Fermi GBM Final Real-time Localization
  39. GRB 240910A: Fermi GBM Observation
  40. GRB 240910A: NOT optical observations
  41. GRB 240911A : a likely weak GRB detected by SVOM/ECLAIRs
  42. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  43. GRB 240910A: JinShan optical observations
  44. GRB 240910A: GOTO candidate optical counterpart
  45. GRB 240710A: SVOM/GRM observation
  46. GRB 240910A: Swift ToO observations
  47. IPN triangulation of GRB 240905B (short)
  48. GRB 240825A: 7DT Optical Upper Limit
  49. GRB 240905E: SVOM/VT optical observations
  50. GRB 240905E: SVOM/VT optical observations (duplicate submission of GCN 37453)
  51. GRB 240910A: GRBAlpha detection
  52. GRB 240910B: Fermi GBM Final Real-time Localization
  53. GRB 240910A: SVOM/GRM observation
  54. EP240908a: Mondy and AbAO follow-up observations
  55. Fermi GRB 240910A: Global MASTER-Net observations report
  56. GRB 240910A: Fermi GBM Final Real-time Localization
  57. LIGO/Virgo/KAGRA S240908bs: Upper limits from Swift/BAT-GUANO
  58. LIGO/Virgo/KAGRA S240907cg: Upper limits from Swift/BAT-GUANO
  59. GRB 240905B: Fermi GBM Observation
  60. GRB 240905B: GOTO optical upper limits
  61. Fermi GRB 240908A: Global MASTER-Net observations report
  62. GRB 240908A: Fermi GBM Final Real-time Localization
  63. GRB 240801A: SVOM/GRM observation
  64. GRB 240905E: GIT optical upper limit
  65. GRB 240905B: Swift-XRT observations
  66. GRB 240905E: Gaoyazi/GOT optical upper limits
  67. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  68. GRB 240905B: Fermi-LAT detection
  69. GRB 240905B: Swift ToO observations
  70. GRB 240905E: J-band observations with WINTER
  71. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  72. GRB 240905E: AKO Optical Upper Limit
  73. GRB 240905E: SVOM/C-GFT optical upper limit
  74. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  75. Fermi GRB 240905D: Global MASTER-Net observations report
  76. Fermi GRB 240905A: Global MASTER-Net observations report
  77. GRB 240905E: NOT optical upper limits
  78. GRB 240905E: REM optical/NIR upper limits
  79. GRB 240902B: AstroSat CZTI detection of a long burst
  80. GRB 240905E: Swift-XRT refined Analysis
  81. GRB 240902A: AstroSat CZTI detection of a long burst
  82. GRB 240905E: SVOM/GRM observation
  83. GRB 240905E: LCOGT Optical Upper Limit
  84. GRB 240905E: Swift/UVOT Upper Limits
  85. GRB 240905E: SAO RAS optical upper limit
  86. GRB 240825A: Montarrenti Observatory optical follow-up observations
  87. GRB 240905E: Nanshan/HMT optical upper limit
  88. Swift GRB 240905E: Global MASTER-Net observations report
  89. GRB 240905E: Swift detection of a burst
  90. GRB 240819A: Optical upper limits from TESS
  91. GRB 240905D: AstroSat CZTI detection
  92. GRB 240905A: SVOM/GRM observation
  93. Fermi GRB 240905B: Global MASTER-Net observations report
  94. GRB 240905D: Fermi GBM Final Real-time Localization
  95. GRB 240905B: AstroSat CZTI detection and localization
  96. GRB 240905C: Fermi GBM Final Real-time Localization
  97. GRB 240905B: Fermi GBM Final Real-time Localization
  98. GRB 240825A: ATCA Detection of Radio Counterpart
  99. Swift GRB 240904A: Global MASTER-Net observations report
  100. GRB 240905A: Fermi GBM Final Real-time Localization

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