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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"

16273 results found.

  1. GRB 200917A: GROWTH-India Telescope optical upper limit.
  2. GRB 200829A: T100 observations
  3. GRB 200907B: Swift/UVOT Upper Limits
  4. GRB 200907B: AstroSat CZTI detection
  5. GRB 200907B: MITSuME Okayama optical upper limits
  6. Correction to GCN 28387: GRB 200907B GROWTH-India optical upper limit
  7. GRB200907A: GROWTH-India optical upper limit
  8. GRB 200906A: Swift/UVOT Upper Limits
  9. GRB 200906A: GROWTH-India Telescope (GIT) optical r band upper limit
  10. GRB 200906A: Nanshan/NEXT optical upper limit
  11. GRB 200829A: optical observations, a light curve in R-filter
  12. ZTF20abtxwfx/AT2020sev : AstroSat CZTI non-detection of a transient
  13. INTEGRAL Weak#8699: AROMA-N Optical Observation
  14. GRB 200901A: Swift/UVOT Detection
  15. GRB 200829A: Koshka Zeiss-1000 optical observations
  16. GRB 200829A: Liverpool Telescope observations
  17. GRB 200829A: Continued Nanshan/NEXT optical observations
  18. GRB 200829A: Kitab optical upper limit
  19. GRB 200829A: further SAO RAS optical observations
  20. GRB 200829A: Nanshan/NEXT optical observations
  21. GRB 200829A: SAO RAS optical observations
  22. GRB 200826A
  23. GRB 200829A: THO optical observatios
  24. GRB200829A: optical afterglow detection
  25. GRB 200826A: Lowell Discovery Telescope observations of ZTF20abwysqy
  26. GRB 200829A: Swift/UVOT Detection
  27. GRB 200829A: TSHAO optical observations
  28. GRB 200829A: Swift detection of a burst with an optical afterglow
  29. GRB 200826A: Kitab optical observations
  30. Zwicky Transient Facility discovery of ZTF20abtxwfx/AT2020sev, a fast optical transient and candidate afterglow
  31. GRB 200826A: VLA Detection at 6 GHz
  32. GRB 200826A: further analysis of the Konus-Wind data and classification
  33. GRB 200826A: Swift-XRT afterglow detection
  34. GRB200826A: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi Short GRB (Trigger 620108997)
  35. GRB 200819A: Swift/UVOT Upper Limits
  36. GRB 200815A: MASTER optical observations
  37. GRB 200819A: Optical Observations from HCT
  38. GRB 200819A: MITSuME Ishigaki optical upper limits
  39. GRB 200819A: MITSuME Akeno optical upper limits
  40. GRB 200819A / Swift J0125.7+6303: Ondrejov Perek-2m optical limit
  41. GRB 200819A: Kitab, TSHAO optical upper limit
  42. HAWC alert 200815.26: MASTER optical observations
  43. GRB 200809B: BOOTES-3/YA optical upper limit
  44. GRB 200806A: Nanshan/NEXT optical upper limit
  45. GRB 200806A: CAHA optical afterglow confirmation
  46. GRB 200803A: Chilescope optical upper limit
  47. GRB 200806A: VIRT optical observations
  48. GRB 200806A: AbAO optical upper limit
  49. GRB 200806A: MITSuME Akeno optical upper limits
  50. GRB 200803A: Fermi GBM detection
  51. GRB 200803A: Swift-XRT afterglow detection
  52. GRB 200803A: MASTER optical counterpart discovery
  53. GRB 200801C: BOOTES-1 and BOOTES-2 optical limits
  54. GRB 200729A: Nanshan/NEXT optical upper limit
  55. GRB 200729A: further analysis of the NOT data
  56. GRB 200729A: Swift/UVOT Upper Limits
  57. GRB 200729A: Pan-STARRS pre-explosion source detection
  58. GRB 200729A: NOT optical upper limits
  59. GRB200729A: BOOTES-1 optical upper limit
  60. GRB 200723A: GOTO candidate afterglow and host galaxy
  61. GRB 200716C: Kitab optical observations
  62. GRB 200716C: CAHA optical observation // Anomalous light curve behavior?
  63. GRB 200716C: CrAO, Terskol, Assy-Turgen optical observations
  64. GRB 200716C: VIRT optical detection.
  65. GRB 200716C: Optical observations from HCT
  66. GRB 200716C: possible host galaxy from the SDSS
  67. GRB200716C: BOOTES-1 optical afterglow detection
  68. Swift GRB200716C: Global MASTER-Net OT detection
  69. GRB 200716C: Swift detection of a burst with an optical counterpart
  70. GRB 200522A: Candidate Optical/nIR Counterpart from Gemini and HST Imaging
  71. GRB 200711A: AbAO optical upper limit
  72. GRB 200711A: Swift/UVOT Upper Limits
  73. GRB 200711A: KAIT Optical Upper Limit
  74. GRB 200630A: Swift/UVOT Upper Limits
  75. GRB 200623A: Further MMTCam Observations of XRT Source #3
  76. GRB 200623A: LBT optical observations
  77. GRB 200623A: TNG optical observations
  78. IceCube-200620A: MASTER previous detection of ZTF20abgvabi/AT2020ncr
  79. IceCube-200620A: One Candidate Counterpart from the Zwicky Transient Facility
  80. GRB 200613A: Continued CrAO optical observations
  81. GRB 200613A: CrAO optical observations
  82. GRB 200613A: continued Kitab optical observations
  83. GRB 200613A: SAO RAS optical observations
  84. GRB 200613A: Mondy optical observations
  85. GRB 200613A: Jet-break from Xinglong-2.16m optical observations
  86. GRB 200613A: MITSuME Akeno optical upper limits
  87. GRB 200613A: continued AbAO optical afterglow observations
  88. GRB 200613A: Continued Xinglong-2.16m optical observations
  89. GRB 200613A: Swift/UVOT Detection
  90. GRB 200613A: Xinglong-2.16m optical observations
  91. GRB 200613A: Liverpool Telescope observations
  92. GRB 200613A: Kitab and AbAO optical afterglow observations, host galaxy candidate
  93. GRB 200613A: Candidate afterglow from OAJ
  94. GRB 200612A: Swift/UVOT Upper Limits
  95. GRB 200612A: Late Optical Maximum Deteted by MASTER
  96. GRB 200612A: BOOTES-3/YA optical upper limit
  97. Swift GRB200612.19: Global MASTER-Net OT detection
  98. GRB 200608A: BOOTES-3 and BOOTES-4 optical upper limit
  99. GRB 200529A: Swift/UVOT Upper Limits
  100. GRB 200529A: MITSuME Akeno optical upper limits

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