1. OSIRIS Cruise Science
The OSIRIS cameras have demonstrated the capability to do competitive science as astronomical telescopes
We should take advantage of this capability !
Keeping in mind lifetime issues
Concentrating on a few promising projects
Considering ESA’s “No cruise science, but exceptions are possible” policy
Purpose of this talk:
Show some examples that came up in discussions within the team
Initiate discussion what should be done

2. 1. Asteroid phase curves
Many asteroids can be observed by OSIRIS with good Signal/Noise over a large range in phase angles
Normally not achievable from Earth
Asteroids with relatively close approaches to Rosetta would be preferred
It is probably not feasible to get close enough to any asteroid (apart from Steins and Lutetia) to resolve it with the NAC

3. Asteroid phase curves
Advantages
Clearly defined scientific goal
Effort and number of exposures controlled by number of target objects
Disadvantages
Science can partly be done by earth-based study of NEAs
Operationally expensive for ESA

4. 2. Observations of comets
OSIRIS already observed 3 comets
Linear 2002/T7 and Machholz 2004/Q2 during commissioning
Tempel 1 during Deep impact
Possible results
Stereo-reconstruction of tail direction and structures
Water production from OH
CS (unobservable from Earth) in case of a very bright comet
Special case of comets 22P/Kopff and 81P/Wild 2: Could be observed in OH and OI in support of H2O observations by Herschel

5. Example of images of bright comets
ESA ©2004 MPS for OSIRIS Team
MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA
Comet LINEAR
ESA ©2005 MPS for OSIRIS Team
MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA
Comet Machholz

6. Observations of bright comets
Advantages
Proven capability of the instrument
Good PR opportunity
Operationally relatively easy
Disadvantages
Added scientific value over earth-based observations is unclear in most cases
Deep Impact was a special case
Exception: Possibility of stereo observations
Herschel support should be seriously considered

7. 3. COROT follow-up
COROT is currently looking for the photometric signal of extrasolar planets in transit of their stars
OSIRIS is in principle capable of a similar transit search
While we do not have the resources for a full search program, participation in the follow-up could be envisaged

8. COROT follow-up Advantages Touches a hot scientific topic
Project in large international context
High visibility
Disadvantages
Operationally demanding
Lifetime issues ?
Unrelated to Rosetta Science

9. 4. Gravitational microlensing
Gravitational microlensing shows a parallax effect on the scale of ~1 AU
Can be observed with near-simultaneous observations of the galactic center with OSIRIS and ground-based telescopes

10. Gravitational microlensing
Advantages
First observation of its kind with strong scientific justification
Good outreach perspective
Can be done with relatively few exposures
Disadvantages
Capability of photometry in relatively crowded field still to be demonstrated
Science is remote from Rosetta science
Difficult to sell to ESA

11. 5. Interstellar Extinction in the UV
The OSIRIS filters below 300 nm operate in a relatively unexplored wavelength range
The WAC with its large field of view may provide new information about interstellar extinction
Extinction peaks at around 250 nm

12. Interstellar Extinction
Advantages
Explores unique capability of OSIRIS
Operationally simple
Data may already be found in existing data sets
Disadvantages
May require a large data volume
Unrelated to Rosetta Science

13. Issues We need to decide if we want to go for Cruise science
If the answer is yes, we need to prioritize and try to get our suggestions into the program
Watch out for serendipitous science opportunities that may be in existing data sets