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').

534 results found.

  1. GRB 200907B: MITSuME Okayama optical upper limits
  2. GRB 200819A: MITSuME Ishigaki optical upper limits
  3. GRB 200819A: MITSuME Akeno optical upper limits
  4. GRB 200806A: MITSuME Akeno optical upper limits
  5. GRB 200613A: MITSuME Akeno optical upper limits
  6. GRB 200529A: MITSuME Akeno optical upper limits
  7. GRB 200528A: MITSuME Akeno optical upper limits
  8. GRB 200524A: optical upper limits from further MITSuME Akeno observation
  9. GRB 200524A: MITSuME Akeno optical observation
  10. GRB 200514A: MITSuME Akeno optical upper limits
  11. GRB 200412B: MITSuME Akeno optical observation
  12. GRB 200324A:MITSuME Akeno optical upper limits
  13. GRB 200227A: MITSuME Akeno optical upper limit
  14. LIGO/Virgo S200213t: No candidates found in J-GEM follow-up observations
  15. GRB 200122A: AstroSat CZTI detection
  16. GRB 200122A: MITSuME Akeno optical upper limits
  17. GRB 200115A: MITSuME Okayama optical upper limits
  18. GRB 191227A: MITSuME Akeno optical upper limits
  19. LIGO/Virgo S191216ap: No candidates found in J-GEM follow-up observations of HAWC error region
  20. LIGO/Virgo S191213g: No candidates found in J-GEM follow-up observations
  21. LIGO/Virgo S191205ah: MITSuME Observation of MASTER OT J123123.61-043847.2
  22. GRB 191031D: AstroSat CZTI detection
  23. GRB 191031D: MITSuME Akeno optical upper limits
  24. GRB191016A: MITSuME Okayama optical observation
  25. LIGO/Virgo S190930t: J-GEM follow-up observations for AT2019rpj
  26. GRB 191001B: MITSuME Akeno optical upper limits
  27. GRB 190926A: MITSuME Akeno optical upper limits
  28. LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations
  29. LIGO/Virgo S190728q: MITSuME Okayama and Bisei Follow-Up of ZTF19abjethn (AT2019lvs)
  30. LIGO/Virgo S190510g: J-GEM optical/NIR follow-up observations
  31. LIGO/Virgo S190412m: Further J-GEM optical/NIR observations
  32. GRB 190427A: MITSuME Akeno optical upper limits
  33. LIGO/Virgo S190412m: J-GEM optical/NIR follow-up observations
  34. GRB 190404C: MITSuME Akeno and Okayama optical upper limits
  35. LIGO-Virgo GW S190408an: J-GEM optical/NIR follow-up observations
  36. GRB 190330A: MITSuME Akeno and Okayama optical upper limits
  37. GRB 190326A: Insight-HXMT/HE detection
  38. GRB 190326A: MITSuME Okayama optical upper limits
  39. GRB190311A: MITSuME Akeno optical observation
  40. GRB190211A: MITSuME Akeno optical observation
  41. GRB190123A: MITSuME Akeno optical upper limits
  42. GRB190109B: MITSuME Akeno optical upper limits
  43. GRB 190114B: MITSuME Akeno optical upper limits
  44. GRB190109A: MITSuME Akeno optical upper limits
  45. GRB 190106A: Swift/UVOT Detection
  46. GRB 190106A: MITSuME Akeno optical observation
  47. GRB 181228A: MITSuME Akeno optical upper limits
  48. GRB 181110A: MITSuME Akeno optical observation
  49. GRB 181103A: MITSuME Okayama optical upper limits
  50. GRB 181022A: MITSuME Akeno optical upper limits
  51. GRB 181011A: MITSuME Akeno and Okayama optical upper limits
  52. GRB 180905A: Swift/UVOT Upper Limits
  53. GRB 180905A: MITSuME Akeno optical upper limits
  54. GRB 180721A: MITSuME Akeno optical upper limits
  55. GRB 180720B: MITSuME Ishigaki optical observations
  56. GRB 180720B: MITSuME Akeno optical observations
  57. GRB 180624A: MITSuME Okayama optical upper limits
  58. GRB 180602A: MITSuME Ishigakijima optical upper limits
  59. GRB 180602A: MITSuME Akeno optical upper limits
  60. GRB 180602A: MITSuME Okayama optical upper limits
  61. GRB 180514A: MITSuME Ishigakijima optical upper limits
  62. GRB 180514A: MITSuME Akeno optical upper limits
  63. GRB 180510A: MITSuME Ishigakijima optical upper limits
  64. GRB 180418A: MITSuME Ishigakijima Optical Observation
  65. GRB 180410A: MITSuME Akeno optical upper limits
  66. GRB 180316A: MITSuME Akeno optical upper limits
  67. GRB 180316A: MITSuME Okayama optical upper limits
  68. GRB 180314A: MITSuME Okayama optical upper limits
  69. GRB 180204A: MITSuME Okayama optical upper limits
  70. GRB 180115A: MITSuME Akeno optical upper limits
  71. GRB 171124A: MITSuME Akeno optical upper limits
  72. GRB 171123A: MITSuME Akeno optical upper limits
  73. GRB 171120A: MITSuME Akeno optical upper limits
  74. GRB 171115A: MITSuME Okayama optical upper limits
  75. GRB 171115A: MITSuME Akeno optical upper limits
  76. GRB 171102B: MITSuME Akeno optical upper limits
  77. GRB 171010A: MITSuME Akeno Optical Observation
  78. GRB 170921A: NOT optical observations
  79. GRB 170921A: MITSuME Okayama upper limits
  80. GRB 170903A: MITSuME Okayama upper limits
  81. GRB 170822A: MITSuME Akeno Optical Observation
  82. GRB 170705A: MITSuME Akeno Optical Observation
  83. GRB 170519A: MITSuME Akeno Optical Observation
  84. GRB 170519A: MITSuME Okayama Optical Observation
  85. GRB 170317A: MITSuME Okayama Optical Observation
  86. GRB 170317A: MITSuME Okayama Ks-band upper-limit
  87. LIGO/Virgo G275404: Nearby galaxy observations by J-GEM collaboration
  88. LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
  89. GRB 170202A: MITSuME Akeno Optical Observation
  90. GRB 161219B: MITSuME Akeno Optical Observation
  91. GRB 161217A: MITSuME Okayama upper limits
  92. GRB 161202A: MITSuME Okayama upper limits
  93. GRB 161129A: MITSuME Okayama Ks-band Observation
  94. GRB 161129A: MITSuME Okayama Optical Observation
  95. GRB 161108A: MITSuME Okayama upper limits
  96. GRB 161017A: MITSuME Akeno Optical Observation
  97. GRB 161014A: Continued MITSuME Akeno Optical Observation
  98. GRB 161014A: Swift/UVOT Detection
  99. GRB 161014A: Swift-XRT and UVOT afterglow detection
  100. GRB 161014A: MITSuME-Akeno optical observation

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