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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').
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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.

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subject:"Swift"
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submitter:"Judith Racusin"

16293 results found.

  1. LIGO/Virgo S190814bv: VLA observation of ASKAP J005547-270433/AT2019osy
  2. LIGO/Virgo S190814bv: Swift UVOT - no new counterpart candidates identified
  3. GRB 190828B: Dabancheng-0.5m optical upper limit
  4. LIGO/Virgo S190814bv: DESGW non-detection of AT2019osy/ASKAP 005547-270433
  5. LIGO/Virgo S190814bv: Palomar 200-in spectroscopic redshift and host galaxy properties of ASKAP source AT2019osy
  6. LIGO/Virgo S190814bv: Optical non-detection of radio source AT2019osy from CFHT
  7. Fermi GBM-190816: Eight additional candidates from the Zwicky Transient Facility
  8. LIGO/Virgo S190814bv: DECam-GROWTH detection of an optical counterpart to the radio source AT2019osy
  9. LIGO/Virgo S190814bv: Final list of candidates from the DESGW coadd analysis from the week long search campaign
  10. LIGO/Virgo S190814bv: CFHTphotometryof AT2019npv
  11. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019npw and AT2019num
  12. LIGO/Virgo S190814bv : Magellan IMACS Spectrum of AT2019npv classified as a Type Ib supernova
  13. LIGO/Virgo S190814bv: SALT optical spectrum of candidate DG19aqbkc
  14. GRB 190824A: Swift/UVOT Upper Limits
  15. LIGO/Virgo S190814bv: No radio counterpart to DG19wxnjc/AT2019npv in ASKAP observations
  16. LIGO/Virgo S190814bv: Keck NIRES spectroscopy of DG19wxnjc/AT2019npv
  17. LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
  18. GRB 190821A: Swift/UVOT Upper Limits
  19. GRB 190821A: MASTER VWFC syncronous optical observations
  20. Fermi GBM-190816: MASTER-Net optical observation report
  21. LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
  22. LIGO/Virgo S190814bv: a potential faint optical counterpart in CFHT imaging
  23. LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
  24. GRB 190821A: T60 Les Makes optical detection of the afterglow
  25. Fermi GBM-190816: Four additional candidates from the Zwicky Transient Facility
  26. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019noq and AT2019ntn
  27. Fermi GBM-190816: ZTF19abqanpy 10.4m GTC spectroscopy
  28. LIGO/Virgo S190814bv: AT2019nqq 10.4m GTC spectroscopy
  29. LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
  30. LIGO/Virgo S190814bv: Additional candidates identified in DECam images by the DECam-GROWTH team
  31. LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
  32. LIGO/Virgo S190814bv: SOAR spectroscopy of 2 DESGW candidates
  33. LIGO/Virgo S190814bv: no candidates from optical imaging of selected galaxies at the NOT
  34. LIGO/Virgo S190814bv: New candidates from DECam DESGW difference imaging search
  35. LIGO/Virgo S190814bv: GROND imaging of candidate galaxies
  36. S190814bv: MASTER analysis of DECam-GROWTH candidates
  37. LIGO/Virgo S190814bv: No candidates identified in DECam data by visual inspection
  38. LIGO/Virgo S190814bv: des-gw190814b is a moving object
  39. LIGO/Virgo S190814bv: No Counterparts in DDOTI/OAN Optical Observations
  40. LIGO/Virgo S190814bv: No counterpart candidates in TOROS observations
  41. LIGO/Virgo S190814bv: no counterpart candidates in Keck I MOSFIRE imaging
  42. LIGO/Virgo S190814bv: MeerLICHT coverage second preliminary skymap
  43. LIGO/Virgo S190814bv Global MASTER-Net optical observations
  44. LIGO/Virgo S190814bv: no candidates from GOTO imaging observations
  45. LIGO/Virgo S190814bv: Candidates found in initial DESGW search
  46. LIGO/Virgo S190814bv: Nordic Optical Telescope imaging of selected galaxies
  47. FRB 190806: MASTER optical observation
  48. LIGO/Virgo S190728q: New optical candidates from the DESGW program
  49. LIGO/Virgo S190728q: AT2019lvw 10.4m GTC spectroscopy
  50. LIGO/Virgo S190728q: AT2019lzc 10.4m GTC spectroscopy
  51. GRB 190731A: Swift/UVOT Upper Limits
  52. GRB 190731A: no OT detected by MASTER
  53. IceCube 190730A: No counterpart candidates or blazar activity in GOTO observations
  54. LIGO/Virgo S190728q: AT2019lzt 10.4m GTC spectroscopy
  55. LIGO/Virgo S190728q: ZTF Forced Photometry for PS1 and DECam-GROWTH optical candidates, and a note on DECam Photometry from GCN 25215
  56. IceCube-190730A: MASTER optical observation
  57. LIGO/Virgo S190728q: MITSuME Okayama and Bisei Follow-Up of ZTF19abjethn (AT2019lvs)
  58. LIGO/Virgo S190728q: Optical transients from Pan-STARRS coverage during first 2 nights
  59. LIGO/Virgo S190728q: Optical Counterpart Candidates from DECam-GROWTH
  60. LIGO/Virgo S190728q: ZTF19abjethn TShAO and NUTTelA-TAO optical observations / classification
  61. LIGO/Virgo S190728q: Classification of AT2019lvs/ZTF19abjethn as a CV
  62. LIGO/Virgo S190728q: Update on Sky-Localization and Source-Classification
  63. LIGO/Virgo S190728q: LCO Follow-Up of ZTF19abjethn (AT2019lvs)
  64. LIGO/Virgo S190728q: Pan-STARRS detection of the transient AT2019lvs/ZTF19abjethn 18hrs before S190728q
  65. LIGO/Virgo S190728q: Identification of a Faint Blue Static Source at the Location of ZTF19abjethn
  66. LIGO/Virgo S190728q: Photometric Redshift and Stellar Mass Estimates for the Potential Host Galaxy of Optical Counterpart Candidate ZTF19abjethn
  67. LIGO/Virgo S190728q: Optical Candidate from the Zwicky Transient Facility ZTF19abjethn
  68. LIGO/Virgo S190718y: Classification of AT 2019lqm / Gaia19dcs as a Type Ia Supernova
  69. LIGO/Virgo S190718y: Classification of AT 2019lqn / Gaia19dct as a Type Ia Supernova
  70. GRB 190719C: optical afterglow confirmation
  71. LIGO/Virgo S190720a: No counterpart candidates in CNEOST observations
  72. GRB 190719C: Swift/UVOT Upper Limits
  73. LIGO/Virgo S190718y: No counterpart candidates in CNEOST
  74. GRB 190719C: NOT candidate optical afterglow and host
  75. GRB 190718A: Swift/UVOT Upper Limits
  76. GRB 190718A: FRAM-Auger optical limit
  77. LIGO/Virgo S190707q: No counterpart candidates in the CNEOST
  78. GRB 190706B: Swift/UVOT Detection
  79. GRB 190627A: Discovery Channel Telescope late time observations
  80. GRB 190530A: Observation of the afterglow by NOEMA
  81. GRB 190701A: Swift/UVOT Upper Limits
  82. GRB190701A: No candidates/counterpart in optical follow-up from GROWTH-India Telescope
  83. GRB 190630B: Tien Shan and Koshka Zeiss-1000 optical upper limits
  84. GRB 190630C: ISON-Castelgrande optical upper limit
  85. GRB 190701A: COATLI Optical Observations
  86. GRB 190630C: Swift/UVOT Upper Limits
  87. GRB 190630C: KAIT Optical Upper Limit
  88. GRB 190630B: Swift/UVOT Upper Limits
  89. GRB 190630B: KAIT Optical Afterglow Confirmation
  90. GRB 190627A: VLT/FORS2 spectroscopic redshift
  91. GRB Swift Trigger 912102: KAIT Optical Afterglow Candidate
  92. GRB 190627A: Koshka Zeiss-1000 optical counterpart observations
  93. GRB 190627A : Xinglong 2.16m optical observation
  94. GRB 190627A: GMG observation at the second epoch
  95. GRB 190627A: NOT optical observations
  96. GRB 190627A: Optical imaging by D50 from Ondrejov
  97. GRB 190627A: Optical imaging and spectroscopy from Calar Alto
  98. GRB 190627A: NUTTelA-TAO optical counterpart observations
  99. GRB 190627A: GMG observation
  100. GRB 190627A: MASTER optical counterpart observation

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